Washington Mutual Mortgage Securities Corp – ‘424B5’ on 8/24/05 re: WaMu Mortgage Pass-Through Certificates, Series 2005-AR11

On:  Wednesday, 8/24/05, at 4:03pm ET   ·   Accession #:  950117-5-3400   ·   File #s:  333-103345, -73

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Prospectus   —   Rule 424(b)(5)
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Document/Exhibit                   Description                      Pages   Size 

 1: 424B5       Washington Mutual 2005 Ar11                          184   1.05M 

Document Table of Contents

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PROSPECTUS SUPPLEMENT TO PROSPECTUS DATED AUGUST 23, 2005 

WAMU MORTGAGE PASS-THROUGH CERTIFICATES,
SERIES 2005-AR11

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. 
DEPOSITOR 

WASHINGTON MUTUAL BANK
SERVICER

$3,127,443,100
(APPROXIMATE) 

--------------------------------------------------------------------------------

CONSIDER CAREFULLY THE RISK FACTORS BEGINNING ON PAGE S-16 IN THIS PROSPECTUS   
SUPPLEMENT AND PAGE 5 IN THE ACCOMPANYING PROSPECTUS.                           

The certificates will represent interests only in the WaMu Mortgage Pass-Through
Certificates Series 2005-AR11 Trust and will not represent interests in or      
obligations of Washington Mutual Mortgage Securities Corp., Washington Mutual,  
Inc. or any of their affiliates.                                                

NEITHER THESE CERTIFICATES NOR THE UNDERLYING MORTGAGE LOANS ARE GUARANTEED BY  
ANY AGENCY OR INSTRUMENTALITY OF THE UNITED STATES.                             

This prospectus supplement may be used to offer and sell the offered            
certificates only if accompanied by the prospectus.                             

--------------------------------------------------------------------------------

THE WAMU MORTGAGE PASS-THROUGH CERTIFICATES SERIES 2005-AR11 TRUST WILL ISSUE   
NINETEEN CLASSES OF OFFERED CERTIFICATES AND FIVE CLASSES OF PRIVATELY PLACED   
CERTIFICATES. EACH CLASS OF CERTIFICATES WILL BE ENTITLED TO RECEIVE MONTHLY    
DISTRIBUTIONS OF INTEREST AND PRINCIPAL. THE TABLE ON PAGE S-4 OF THIS          
PROSPECTUS SUPPLEMENT CONTAINS A LIST OF THE CLASSES OF OFFERED CERTIFICATES,   
INCLUDING THE INITIAL CLASS PRINCIPAL BALANCE, CERTIFICATE INTEREST RATE, AND   
SPECIAL CHARACTERISTICS OF EACH CLASS.                                          

OFFERED CERTIFICATES                                                            
--------------------                                                            

                                                                [Download Table]
                                                                 
Total principal amount (approximate)           $3,127,443,100    

First payment date                             September 26, 2005

Interest and/or principal paid                 Monthly           

Last payment date                              August 25, 2045   

Credit enhancement for the offered certificates is being provided by four       
classes of privately offered certificates, which have an aggregate principal    
balance of approximately $73,626,194.                                           

WaMu Capital Corp. and Greenwich Capital Markets, Inc., as underwriters, will   
purchase the offered certificates from Washington Mutual Mortgage Securities    
Corp. in the amounts described in 'Method of Distribution' on page S-77 of this 
prospectus supplement. The underwriters will offer the offered certificates at  
varying prices to be determined at the time of sale. The proceeds to Washington 
Mutual Mortgage Securities Corp. from the sale of the offered certificates will 
be approximately 101.58% of the principal balance of the offered certificates   
plus accrued interest, before deducting expenses. Each underwriter's commission 
will be the difference between the price it pays to Washington Mutual Mortgage  
Securities Corp. for the offered certificates and the amount it receives from   
the sale of the offered certificates to the public.                             

NEITHER THE SEC NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED 
OF THE OFFERED CERTIFICATES OR DETERMINED THAT THIS PROSPECTUS SUPPLEMENT OR THE
PROSPECTUS IS ACCURATE OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A     
CRIMINAL OFFENSE.                                                               

Underwriters

WAMU CAPITAL CORP.                                         RBS GREENWICH CAPITAL
(Co-Lead Underwriters and Joint Book Running Managers)

August 23, 2005 

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IMPORTANT NOTICE ABOUT INFORMATION PRESENTED IN THIS
PROSPECTUS SUPPLEMENT AND THE ACCOMPANYING PROSPECTUS 

    We provide information to you about the offered certificates in two separate
documents that progressively provide more detail: (a) the accompanying          
prospectus, which provides general information, some of which may not apply to  
your series of certificates, and (b) this prospectus supplement, which describes
the specific terms of your series of certificates.                              

 IF THE TERMS OF YOUR CERTIFICATES VARY BETWEEN THIS PROSPECTUS SUPPLEMENT
AND THE ACCOMPANYING PROSPECTUS, YOU SHOULD RELY ON THE INFORMATION IN THIS     
PROSPECTUS SUPPLEMENT.                                                          

We include cross-references in this prospectus supplement and the       
accompanying prospectus to captions in these materials where you can find       
further related discussions. The following table of contents and the table of   
contents included in the accompanying prospectus provide the pages on which     
these captions are located.                                                     

    You can find a listing of the pages where some of the capitalized terms used
in this prospectus supplement and the accompanying prospectus are defined under 
the caption 'Index of Terms' on page S-94 in this prospectus supplement and     
under the caption 'Index of Terms' beginning on page 88 in the accompanying     
prospectus. Capitalized terms used in this prospectus supplement and not        
otherwise defined in this prospectus supplement have the meanings assigned in   
the accompanying prospectus.                                                    

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TABLE OF CONTENTS 

                                                                [Download Table]

                                         PAGE
                                         ----
                                             
SUMMARY INFORMATION...................    S-4
    What You Own......................    S-4
        Information About the Mortgage       
          Pool........................    S-4
    The Offered Certificates..........    S-4
        Initial Principal Balance of         
          the Certificates............   S-10
    Distributions on the                     
      Certificates....................   S-10
        Monthly Distributions.........   S-10
        Distributions of Interest.....   S-10
        Compensating Interest and            
          Interest Shortfalls.........   S-12
        Distributions of Principal....   S-12
    Credit Enhancements...............   S-13
    Yield Maintenance Agreement.......   S-13
    Allocation of Losses..............   S-14
    Yield Considerations..............   S-14
    Book-Entry Registration...........   S-14
    Denominations.....................   S-14
    Legal Investment..................   S-14
    ERISA Considerations..............   S-15
    Federal Income Tax Consequences...   S-15
    Ratings...........................   S-15
RISK FACTORS..........................   S-16
THE TRUST.............................   S-29
DESCRIPTION OF THE MORTGAGE POOL......   S-30
    The Index.........................   S-32
    Additional Information............   S-33
DESCRIPTION OF THE CERTIFICATES.......   S-35
    General...........................   S-35
    Book-Entry Registration...........   S-36
    Definitive Certificates...........   S-40
    Priority of Distributions.........   S-41
    Distributions of Interest.........   S-43
    Calculation of LIBOR..............   S-46
    Distributions of Principal........   S-48
        General.......................   S-48
        Senior Principal Distribution        
          Amount......................   S-48
        Subordinate Principal                
          Distribution Amount.........   S-50
    Principal Prepayments.............   S-50
    Subordination and Allocation of          
      Losses..........................   S-51
    The Class R Certificates..........   S-53
    Advances..........................   S-53
    Available Distribution Amount.....   S-53
    Last Scheduled Distribution              
      Date............................   S-54
    Optional Termination of the              
      Trust...........................   S-54
    Servicing Compensation and Payment       
      of Expenses.....................   S-55
    Special Servicing Agreements......   S-55
    Reports to Certificateholders.....   S-55
DELINQUENCY, LOSS AND FORECLOSURE            
  EXPERIENCE..........................   S-56
YIELD AND PREPAYMENT CONSIDERATIONS...   S-57
    General...........................   S-57
    Principal Prepayments and                
      Compensating Interest...........   S-58
    LIBOR Certificates................   S-58
    Rate of Payments..................   S-58
    Prepayment Assumptions............   S-59
    Lack of Historical Prepayment            
      Data............................   S-63
    Yield Considerations with Respect        
      to the Class X Certificates.....   S-63
    Yield Considerations with Respect        
      to the Senior Subordinate              
      Certificates....................   S-65
    Additional Yield Considerations          
      Applicable Solely to the Class R       
      Certificates....................   S-68
    Additional Information............   S-68
CREDIT ENHANCEMENTS...................   S-69
    Subordination.....................   S-69
    Shifting of Interests.............   S-69
YIELD MAINTENANCE AGREEMENT...........   S-69
CERTAIN FEDERAL INCOME TAX                   
  CONSEQUENCES........................   S-70
    Special Tax Considerations               
      Applicable to the Class A and          
      Class B Certificates............   S-71
    Taxation of the Cap Agreement            
      Portion of the Class X                 
      Certificates....................   S-72
    Special Tax Considerations               
      Applicable to the Residual             
      Certificates....................   S-73
    Penalty Protection................   S-74
CERTAIN LEGAL INVESTMENT ASPECTS......   S-75
ERISA CONSIDERATIONS..................   S-75
METHOD OF DISTRIBUTION................   S-77
LEGAL MATTERS.........................   S-78
CERTIFICATE RATINGS...................   S-78
APPENDIX A: DECREMENT TABLES..........   S-79
APPENDIX B: MORTGAGE LOAN TABLES......   S-81
APPENDIX C: GLOBAL CLEARANCE,                
  SETTLEMENT AND TAX DOCUMENTATION           
  PROCEDURES..........................   S-88
SCHEDULE 1............................   S-92
INDEX OF TERMS........................   S-94

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SUMMARY INFORMATION 

THE FOLLOWING SUMMARY HIGHLIGHTS SELECTED INFORMATION FROM THIS PROSPECTUS      
SUPPLEMENT. IT DOES NOT CONTAIN ALL OF THE INFORMATION THAT YOU NEED TO CONSIDER
IN MAKING YOUR INVESTMENT DECISION. TO UNDERSTAND THE TERMS OF THE OFFERED      
CERTIFICATES, READ CAREFULLY THIS ENTIRE PROSPECTUS SUPPLEMENT AND THE          
ACCOMPANYING PROSPECTUS.                                                        

THIS SUMMARY PROVIDES AN OVERVIEW OF CERTAIN CALCULATIONS, CASH FLOWS AND OTHER 
INFORMATION TO AID YOUR UNDERSTANDING. THIS SUMMARY IS QUALIFIED BY THE FULL    
DESCRIPTION OF THESE CALCULATIONS, CASH FLOWS AND OTHER INFORMATION IN THIS     
PROSPECTUS SUPPLEMENT AND THE ACCOMPANYING PROSPECTUS.                          

WHAT YOU OWN                                                                    

YOUR CERTIFICATES REPRESENT INTERESTS ONLY IN THE ASSETS OF THE TRUST. ALL      
PAYMENTS TO YOU WILL COME ONLY FROM THE AMOUNTS RECEIVED IN CONNECTION WITH     
THOSE ASSETS.                                                                   

The Trust owns a pool of mortgage loans and other assets, as described under    
'The Trust' in this prospectus supplement.                                      

INFORMATION ABOUT THE MORTGAGE POOL                                             

The mortgage pool consists of 5,077 mortgage loans with an aggregate principal  
balance as of August 1, 2005 of approximately $3,201,069,294. All of the        
mortgage loans are secured by residential properties (or shares of cooperative  
apartments) and each has an original term to maturity of not more than 40 years.
The mortgage loans sold to the WaMu Mortgage Pass-Through Certificates          
Series 2005-AR11 Trust were purchased by Washington Mutual Mortgage Securities  
Corp. directly from Washington Mutual Bank, an affiliate of Washington Mutual   
Mortgage Securities Corp.                                                       

After an initial fixed-rate period for some of the mortgage loans of one, two,  
three or twelve months, the interest rate on each mortgage loan will adjust     
monthly to equal the sum of an index and a margin. As of August 1, 2005, none of
the mortgage loans were still in their initial fixed-rate period. The interest  
rates on the mortgage loans are subject to overall maximum and minimum interest 
rate limits.                                                                    

The index for the mortgage loans will be One-Year MTA, the 12-month moving      
average yield on United States Treasury Securities adjusted to a constant       
maturity of one year.                                                           

While the interest rate on each mortgage loan will adjust monthly (after the    
initial fixed-rate period), the minimum monthly payment on each mortgage loan   
generally will adjust only annually. On each annual payment adjustment date, the
minimum monthly payment generally will not increase or decrease by more than    
7.5%. As a result, the interest due with respect to a mortgage loan for any     
given month may, under certain circumstances, exceed the monthly payment for    
that month. In that case, payment of the excess of interest due over the monthly
payment will be deferred and that excess will be added to the principal balance 
of that mortgage loan in the form of 'negative amortization.' See 'Description  
of the Mortgage Pool' in this prospectus supplement.                            

For a further description of the mortgage loans, see 'Description of the        
Mortgage Pool' and Appendix B in this prospectus supplement.                    

THE OFFERED CERTIFICATES                                                        

Washington Mutual Mortgage Securities Corp. will sell the mortgage loans to the 
Trust. The Trust is being created for the purpose of issuing the WaMu Mortgage  
Pass-Through Certificates, Series 2005-AR11. The approximate initial class      
principal balance, annual certificate interest rate and type of each class of   
the offered certificates will be as follows:                                    

                                                                [Download Table]

        APPROXIMATE                                           
       INITIAL CLASS       ANNUAL                             
         PRINCIPAL       CERTIFICATE                          
CLASS     BALANCE       INTEREST RATE           TYPE          
--------------------------------------------------------------
                                                              
A-1A   $1,742,982,000    Variable(1)        Senior/LIBOR      
A-1B1     200,385,000    Variable(2)   Senior/LIBOR/Mezzanine 
A-1B2      80,750,000    Variable(3)   Senior/LIBOR/Mezzanine 
A-1B3     445,107,000    Variable(4)   Senior/LIBOR/Mezzanine 
A-1C1     168,605,000    Variable(5)   Senior/LIBOR/Mezzanine 
A-1C2     104,932,000    Variable(6)   Senior/LIBOR/Mezzanine 
A-1C3     110,082,000    Variable(7)   Senior/LIBOR/Mezzanine 
A-1C4      52,127,000    Variable(8)   Senior/LIBOR/Mezzanine 
X                  (9)  Variable(10)        Senior/IO/PO      
B-1        62,421,000   Variable(11)      Subordinate/LIBOR   
B-2        44,815,000   Variable(12)      Subordinate/LIBOR   
B-3        22,407,000   Variable(13)      Subordinate/LIBOR   
B-4        22,407,000   Variable(14)      Subordinate/LIBOR   
B-5        19,206,000   Variable(15)      Subordinate/LIBOR   
B-6        17,606,000   Variable(16)      Subordinate/LIBOR   
B-7        11,204,000   Variable(17)      Subordinate/LIBOR   
B-8         9,603,000   Variable(17)      Subordinate/LIBOR   
B-9        12,804,000   Variable(17)      Subordinate/LIBOR   
R                 100      4.704%          Senior/Residual    

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 (1) For each distribution date on or before the date (the 'CLEAN-UP CALL OPTION
     DATE') on which the aggregate principal balance of the mortgage loans owned
by the Trust has been reduced to less than 10% of that balance as of  
August 1, 2005, the annual certificate interest rate on the Class A-1A
  Certificates will equal the least of (x) the product of (i) the weighted
 average of the mortgage interest rates on the mortgage loans (as of the
  second preceding due date after giving effect to the payments due on the
mortgage loans on that due date) less the per annum rate at which the 
    servicing fee is calculated and (ii) a fraction, the numerator of which is
     30 and the denominator of which is the actual number of days in the related
 certificate accrual period (the 'ADJUSTED WEIGHTED AVERAGE PASS-THROUGH
 RATE'), (y) LIBOR (the London Interbank Offered Rate for one-month U.S.
     dollar deposits, as described in this prospectus supplement) plus 0.32% and
     (z) 10.50%. For each distribution date after the Clean-Up Call Option Date,
  the annual certificate interest rate on the Class A-1A Certificates will
 equal the least of (x) the Adjusted Weighted Average Pass-Through Rate,
     (y) LIBOR plus 0.64% and (z) 10.50%. For the initial distribution date, the
    annual certificate interest rate on these certificates will equal LIBOR as
     of August 23, 2005 plus 0.32%. In addition, if on any distribution date the
  certificate interest rate on the Class A-1A Certificates is equal to the
  Adjusted Weighted Average Pass-Through Rate, the Class A-1A Certificates
   may be entitled to receive, as interest, carryover shortfall amounts from
     amounts, if any, paid under a yield maintenance agreement and from amounts,
     if any, otherwise payable to the Class X Certificates, as described in this
prospectus supplement. See 'Description of the Certificates --        
Distributions of Interest' in this prospectus supplement.             

(2) For each distribution date on or before the Clean-Up Call Option Date, the
     annual certificate interest rate on the Class A-1B1 Certificates will equal
the least of (x) the Adjusted Weighted Average Pass-Through Rate,     
   (y) LIBOR plus 0.29% and (z) 10.50%. For each distribution date after the
Clean-Up Call Option Date, the annual certificate interest rate on the
    Class A-1B1 Certificates will equal the least of (x) the Adjusted Weighted
 Average Pass-Through Rate, (y) LIBOR plus 0.58% and (z) 10.50%. For the
  initial distribution date, the annual certificate interest rate on these
certificates will equal LIBOR as of August 23, 2005 plus 0.29%. In    
    addition, if on any distribution date the certificate interest rate on the
  Class A-1B1 Certificates is equal to the Adjusted Weighted Average Pass-
   Through Rate, the Class A-1B1 Certificates may be entitled to receive, as
  interest, carryover shortfall amounts from amounts, if any, paid under a
    yield maintenance agreement and from amounts, if any, otherwise payable to
   the Class X Certificates, as described in this prospectus supplement. See
'Description of the Certificates -- Distributions of Interest' in this
prospectus supplement.                                                

(3) For each distribution date on or before the Clean-Up Call Option Date, the
     annual certificate interest rate on the Class A-1B2 Certificates will equal
the least of (x) the Adjusted Weighted Average Pass-Through Rate,     
   (y) LIBOR plus 0.45% and (z) 10.50%. For each distribution date after the
Clean-Up Call Option Date, the annual certificate interest rate on the
    Class A-1B2 Certificates will equal the least of (x) the Adjusted Weighted
 Average Pass-Through Rate, (y) LIBOR plus 0.90% and (z) 10.50%. For the
  initial distribution date, the annual certificate interest rate on these
certificates will equal LIBOR as of August 23, 2005 plus 0.45%. In    
    addition, if on any distribution date the certificate interest rate on the
  Class A-1B2 Certificates is equal to the Adjusted Weighted Average Pass-
   Through Rate, the Class A-1B2 Certificates may be entitled to receive, as
  interest, carryover shortfall amounts from amounts, if any, paid under a
    yield maintenance agreement and from amounts, if any, otherwise payable to
   the Class X Certificates, as described in this prospectus supplement. See
'Description of the Certificates -- Distributions of Interest' in this
prospectus supplement.                                                

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(4) For each distribution date on or before the Clean-Up Call Option Date, the
     annual certificate interest rate on the Class A-1B3 Certificates will equal
the least of (x) the Adjusted Weighted Average Pass-Through Rate,     
   (y) LIBOR plus 0.40% and (z) 10.50%. For each distribution date after the
Clean-Up Call Option Date, the annual certificate interest rate on the
    Class A-1B3 Certificates will equal the least of (x) the Adjusted Weighted
 Average Pass-Through Rate, (y) LIBOR plus 0.80% and (z) 10.50%. For the
  initial distribution date, the annual certificate interest rate on these
certificates will equal LIBOR as of August 23, 2005 plus 0.40%. In    
    addition, if on any distribution date the certificate interest rate on the
  Class A-1B3 Certificates is equal to the Adjusted Weighted Average Pass-
   Through Rate, the Class A-1B3 Certificates may be entitled to receive, as
  interest, carryover shortfall amounts from amounts, if any, paid under a
    yield maintenance agreement and from amounts, if any, otherwise payable to
   the Class X Certificates, as described in this prospectus supplement. See
'Description of the Certificates -- Distributions of Interest' in this
prospectus supplement.                                                

(5) For each distribution date on or before the Clean-Up Call Option Date, the
     annual certificate interest rate on the Class A-1C1 Certificates will equal
the least of (x) the Adjusted Weighted Average Pass-Through Rate,     
   (y) LIBOR plus 0.20% and (z) 10.50%. For each distribution date after the
Clean-Up Call Option Date, the annual certificate interest rate on the
    Class A-1C1 Certificates will equal the least of (x) the Adjusted Weighted
 Average Pass-Through Rate, (y) LIBOR plus 0.40% and (z) 10.50%. For the
  initial distribution date, the annual certificate interest rate on these
certificates will equal LIBOR as of August 23, 2005 plus 0.20%. In    
    addition, if on any distribution date the certificate interest rate on the
  Class A-1C1 Certificates is equal to the Adjusted Weighted Average Pass-
   Through Rate, the Class A-1C1 Certificates may be entitled to receive, as
  interest, carryover shortfall amounts from amounts, if any, paid under a
    yield maintenance agreement and from amounts, if any, otherwise payable to
   the Class X Certificates, as described in this prospectus supplement. See
'Description of the Certificates -- Distributions of Interest' in this
prospectus supplement.                                                

(6) For each distribution date on or before the Clean-Up Call Option Date, the
     annual certificate interest rate on the Class A-1C2 Certificates will equal
the least of (x) the Adjusted Weighted Average Pass-Through Rate,     
   (y) LIBOR plus 0.42% and (z) 10.50%. For each distribution date after the
Clean-Up Call Option Date, the annual certificate interest rate on the
    Class A-1C2 Certificates will equal the least of (x) the Adjusted Weighted
 Average Pass-Through Rate, (y) LIBOR plus 0.84% and (z) 10.50%. For the
  initial distribution date, the annual certificate interest rate on these
certificates will equal LIBOR as of August 23, 2005 plus 0.42%. In    
    addition, if on any distribution date the certificate interest rate on the
  Class A-1C2 Certificates is equal to the Adjusted Weighted Average Pass-
   Through Rate, the Class A-1C2 Certificates may be entitled to receive, as
  interest, carryover shortfall amounts from amounts, if any, paid under a
    yield maintenance agreement and from amounts, if any, otherwise payable to
   the Class X Certificates, as described in this prospectus supplement. See
'Description of the Certificates -- Distributions of Interest' in this
prospectus supplement.                                                

(7) For each distribution date on or before the Clean-Up Call Option Date, the
     annual certificate interest rate on the Class A-1C3 Certificates will equal
the least of (x) the Adjusted Weighted Average Pass-Through Rate,     
   (y) LIBOR plus 0.51% and (z) 10.50%. For each distribution date after the
Clean-Up Call Option Date, the annual certificate interest rate on the
    Class A-1C3 Certificates will equal the least of (x) the Adjusted Weighted
  Average Pass-Through Rate, (y) LIBOR plus 1.02 % and (z) 10.50%. For the
  initial distribution date, the annual certificate interest rate on these
certificates will equal LIBOR as of August 23, 2005 plus 0.51%. In    
addition, if on any distribution date the certificate interest        

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rate on the Class A-1C3 Certificates is equal to the Adjusted Weighted
    Average Pass-Through Rate, the Class A-1C3 Certificates may be entitled to
 receive, as interest, carryover shortfall amounts from amounts, if any,
paid under a yield maintenance agreement and from amounts, if any,    
otherwise payable to the Class X Certificates, as described in this   
prospectus supplement. See 'Description of the Certificates --        
Distributions of Interest' in this prospectus supplement.             

(8) For each distribution date on or before the Clean-Up Call Option Date, the
     annual certificate interest rate on the Class A-1C4 Certificates will equal
the least of (x) the Adjusted Weighted Average Pass-Through Rate,     
   (y) LIBOR plus 0.44% and (z) 10.50%. For each distribution date after the
Clean-Up Call Option Date, the annual certificate interest rate on the
    Class A-1C4 Certificates will equal the least of (x) the Adjusted Weighted
 Average Pass-Through Rate, (y) LIBOR plus 0.88% and (z) 10.50%. For the
  initial distribution date, the annual certificate interest rate on these
certificates will equal LIBOR as of August 23, 2005 plus 0.44%. In    
    addition, if on any distribution date the certificate interest rate on the
  Class A-1C4 Certificates is equal to the Adjusted Weighted Average Pass-
   Through Rate, the Class A-1C4 Certificates may be entitled to receive, as
  interest, carryover shortfall amounts from amounts, if any, paid under a
    yield maintenance agreement and from amounts, if any, otherwise payable to
   the Class X Certificates, as described in this prospectus supplement. See
'Description of the Certificates -- Distributions of Interest' in this
prospectus supplement.                                                

(9) Solely for purposes of calculating distributions of principal and interest
  and the allocation of losses realized on the mortgage loans, the Class X
   Certificates will be deemed to be comprised of an interest-only component
  and a principal-only component. The Class X interest-only component will
  have a notional amount (as described below). Interest will accrue on the
    Class X notional amount. The Class X interest-only component will not have
   a principal balance and principal will not be payable with respect to the
     Class X notional amount. The Class X interest-only component corresponds to
 the mortgage loans and payments of interest with respect to the Class X
interest-only component will be based on collections from the mortgage
    loans. The Class X principal-only component will have a principal balance,
  which initially will equal zero. Interest will not accrue on the Class X
principal-only component. In the event that interest accrued on the   
 Class X notional amount is reduced as a result of the allocation of net
negative amortization (as described in 'Description of the            
    Certificates -- Distributions of Interest' in this prospectus supplement),
such amount will be added as principal to the outstanding component   
 principal balance of the Class X principal-only component, in an amount
   equal to the amount of such reduction attributable to the mortgage loans.

(10) For each distribution date, the Class X Certificates will accrue interest  
  on the Class X notional amount, which will equal the aggregate principal
balance of the mortgage loans as of the second preceding due date. The
   initial Class X notional amount will be approximately $3,201,069,294. For
each distribution date, the annual certificate interest rate on the   
 Class X Certificates will equal the excess, if any, of (x) the weighted
 average of the mortgage interest rates on the mortgage loans (as of the
  second preceding due date after giving effect to the payments due on the
mortgage loans on that due date) less the per annum rate at which the 
     servicing fee is calculated (the 'WEIGHTED AVERAGE PASS-THROUGH RATE') over
(y) the product of (i) the weighted average of the annual certificate 
  interest rates on the certificates (other than the Class X Certificates)
    (each of which annual certificate interest rates, in the case of the Class
     A Certificates, will be multiplied by a fraction, the numerator of which is
     the actual number of days in the related certificate accrual period and the
    denominator of which is 30) and (ii) a fraction, the numerator of which is
  the aggregate class principal balance of the certificates (excluding the
principal-only                                                        

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component of the Class X Certificates) immediately prior to that      
   distribution date and the denominator of which is the aggregate principal
balance of the mortgage loans as of the second preceding due date.    
 Notwithstanding the foregoing, amounts to be distributed to the Class X
     Certificates in respect of interest accrued on their notional amount on any
     distribution date may instead be distributed as carryover shortfall amounts
   that are not covered by amounts payable pursuant to the yield maintenance
agreement. See 'Description of the Certificates -- Distributions of   
Interest' in this prospectus supplement.                              

(11) For each distribution date on or before the Clean-Up Call Option Date, the 
   annual certificate interest rate on the Class B-1 Certificates will equal
 the least of (x) the Weighted Average Pass-Through Rate, (y) LIBOR plus
  0.61% and (z) 10.50%. For each distribution date after the Clean-Up Call
Option Date, the annual certificate interest rate on the Class B-1    
    Certificates will equal the least of (x) the Weighted Average Pass-Through
  Rate, (y) LIBOR plus 0.915% and (z) 10.50%. For the initial distribution
     date, the annual certificate interest rate on these certificates will equal
     LIBOR as of August 23, 2005 plus 0.61%. In addition, if on any distribution
   date the certificate interest rate on the Class B-1 Certificates is equal
   to the Weighted Average Pass-Through Rate, the Class B-1 Certificates may
be entitled to receive, as interest, carryover shortfall amounts from 
amounts, if any, otherwise payable to the Class X Certificates, as    
described in this prospectus supplement. See 'Description of the      
   Certificates -- Distributions of Interest' in this prospectus supplement.

(12) For each distribution date on or before the Clean-Up Call Option Date, the 
   annual certificate interest rate on the Class B-2 Certificates will equal
 the least of (x) the Weighted Average Pass-Through Rate, (y) LIBOR plus
  0.63% and (z) 10.50%. For each distribution date after the Clean-Up Call
Option Date, the annual certificate interest rate on the Class B-2    
    Certificates will equal the least of (x) the Weighted Average Pass-Through
  Rate, (y) LIBOR plus 0.945% and (z) 10.50%. For the initial distribution
     date, the annual certificate interest rate on these certificates will equal
     LIBOR as of August 23, 2005 plus 0.63%. In addition, if on any distribution
   date the certificate interest rate on the Class B-2 Certificates is equal
   to the Weighted Average Pass-Through Rate, the Class B-2 Certificates may
be entitled to receive, as interest, carryover shortfall amounts from 
amounts, if any, otherwise payable to the Class X Certificates, as    
described in this prospectus supplement. See 'Description of the      
   Certificates -- Distributions of Interest' in this prospectus supplement.

(13) For each distribution date on or before the Clean-Up Call Option Date, the 
   annual certificate interest rate on the Class B-3 Certificates will equal
 the least of (x) the Weighted Average Pass-Through Rate, (y) LIBOR plus
  0.68% and (z) 10.50%. For each distribution date after the Clean-Up Call
Option Date, the annual certificate interest rate on the Class B-3    
    Certificates will equal the least of (x) the Weighted Average Pass-Through
 Rate, (y) LIBOR plus 1.02% and (z) 10.50%. For the initial distribution
     date, the annual certificate interest rate on these certificates will equal
     LIBOR as of August 23, 2005 plus 0.68%. In addition, if on any distribution
   date the certificate interest rate on the Class B-3 Certificates is equal
   to the Weighted Average Pass-Through Rate, the Class B-3 Certificates may
be entitled to receive, as interest, carryover shortfall amounts from 
amounts, if any, otherwise payable to the Class X Certificates, as    
described in this prospectus supplement. See 'Description of the      
   Certificates -- Distributions of Interest' in this prospectus supplement.

(14) For each distribution date on or before the Clean-Up Call Option Date, the 
   annual certificate interest rate on the Class B-4 Certificates will equal
 the least of (x) the Weighted Average Pass-Through Rate, (y) LIBOR plus
  0.85% and (z) 10.50%. For each distribution date after the Clean-Up Call
Option Date, the annual certificate interest rate on the Class B-4    
    Certificates will equal the least of (x) the Weighted Average Pass-Through
Rate, (y) LIBOR plus 1.275% and                                       

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(z) 10.50%. For the initial distribution date, the annual certificate 
    interest rate on these certificates will equal LIBOR as of August 23, 2005
plus 0.85%. In addition, if on any distribution date the certificate  
interest rate on the Class B-4 Certificates is equal to the Weighted  
  Average Pass-Through Rate, the Class B-4 Certificates may be entitled to
 receive, as interest, carryover shortfall amounts from amounts, if any,
otherwise payable to the Class X Certificates, as described in this   
prospectus supplement. See 'Description of the Certificates --        
Distributions of Interest' in this prospectus supplement.             

(15) For each distribution date on or before the Clean-Up Call Option Date, the 
   annual certificate interest rate on the Class B-5 Certificates will equal
 the least of (x) the Weighted Average Pass-Through Rate, (y) LIBOR plus
  0.95% and (z) 10.50%. For each distribution date after the Clean-Up Call
Option Date, the annual certificate interest rate on the Class B-5    
    Certificates will equal the least of (x) the Weighted Average Pass-Through
  Rate, (y) LIBOR plus 1.425% and (z) 10.50%. For the initial distribution
     date, the annual certificate interest rate on these certificates will equal
     LIBOR as of August 23, 2005 plus 0.95%. In addition, if on any distribution
   date the certificate interest rate on the Class B-5 Certificates is equal
   to the Weighted Average Pass-Through Rate, the Class B-5 Certificates may
be entitled to receive, as interest, carryover shortfall amounts from 
amounts, if any, otherwise payable to the Class X Certificates, as    
described in this prospectus supplement. See 'Description of the      
   Certificates -- Distributions of Interest' in this prospectus supplement.

(16) For each distribution date on or before the Clean-Up Call Option Date, the 
   annual certificate interest rate on the Class B-6 Certificates will equal
 the least of (x) the Weighted Average Pass-Through Rate, (y) LIBOR plus
  1.05% and (z) 10.50%. For each distribution date after the Clean-Up Call
Option Date, the annual certificate interest rate on the Class B-6    
    Certificates will equal the least of (x) the Weighted Average Pass-Through
  Rate, (y) LIBOR plus 1.575% and (z) 10.50%. For the initial distribution
     date, the annual certificate interest rate on these certificates will equal
     LIBOR as of August 23, 2005 plus 1.05%. In addition, if on any distribution
   date the certificate interest rate on the Class B-6 Certificates is equal
   to the Weighted Average Pass-Through Rate, the Class B-6 Certificates may
be entitled to receive, as interest, carryover shortfall amounts from 
amounts, if any, otherwise payable to the Class X Certificates, as    
described in this prospectus supplement. See 'Description of the      
   Certificates -- Distributions of Interest' in this prospectus supplement.

(17) For each distribution date on or before the Clean-Up Call Option Date, the 
    annual certificate interest rate on the Class B-7, Class B-8 and Class B-9
    Certificates will equal the least of (x) the Weighted Average Pass-Through
     Rate, (y) LIBOR plus 1.20% and (z) 10.50%. For each distribution date after
    the Clean-Up Call Option Date, the annual certificate interest rate on the
     Class B-7, Class B-8 and Class B-9 Certificates will equal the least of (x)
the Weighted Average Pass-Through Rate, (y) LIBOR plus 1.80% and (z)  
    10.50%. For the initial distribution date, the annual certificate interest
rate on these certificates will equal LIBOR as of August 23, 2005 plus
  1.20%. In addition, if on any distribution date the certificate interest
     rate on the Class B-7, Class B-8 and Class B-9 Certificates is equal to the
    Weighted Average Pass-Through Rate, the Class B-7, Class B-8 and Class B-9
   Certificates may be entitled to receive, as interest, carryover shortfall
amounts from amounts, if any, otherwise payable to the Class X        
    Certificates, as described in this prospectus supplement. See 'Description
of the Certificates -- Distributions of Interest' in this prospectus  
supplement.                                                           

The Trust will also issue the Class B-10, Class B-11, Class B-12, Class B-13 and
Class PPP Certificates, which are not being offered by this prospectus          
supplement. The Class PPP Certificates will not have a principal balance and    
will not accrue interest. The Class PPP Certificates will be entitled to receive
prepayment penalties paid by borrowers upon                                     

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voluntary full prepayment of approximately 82.9% (by aggregate principal balance
as of August 1, 2005) of the mortgage loans. Accordingly, these amounts will not
be available for distribution to other classes of certificates. The Class B-10, 
Class B-11, Class B-12 and Class B-13 Certificates are subordinated to the      
offered certificates and provide credit enhancement for the offered             
certificates. For each distribution date on or before the Clean-Up Call Option  
Date, the annual certificate interest rate on the Class B-10, Class B-11,       
Class B-12 and Class B-13 Certificates will equal the least of (x) the Weighted 
Average Pass-Through Rate, (y) LIBOR plus 1.20% and (z) 10.50%. For each        
distribution date after the Clean-Up Call Option Date, the annual certificate   
interest rate on the Class B-10, Class B-11, Class B-12 and Class B-13          
Certificates will equal the least of (x) the Weighted Average Pass-Through Rate,
(y) LIBOR plus 1.80% and (z) 10.50%. For the initial distribution date, the     
annual certificate interest rate on these certificates will equal LIBOR as of   
August 23, 2005 plus 1.20%. In addition, if on any distribution date the        
certificate interest rate on the Class B-10, Class B-11, Class B-12 and Class   
B-13 Certificates is equal to the Weighted Average Pass-Through Rate, the       
Class B-10, Class B-11, Class B-12 and Class B-13 Certificates may be entitled  
to receive, as interest, carryover shortfall amounts from amounts, if any,      
otherwise payable to the Class X Certificates, as described in this prospectus  
supplement. See 'Description of the Certificates -- Subordination and Allocation
of Losses' in this prospectus supplement.                                       

INITIAL PRINCIPAL BALANCE OF THE CERTIFICATES                                   

The initial aggregate principal balance of the certificates issued by the Trust 
is approximately $3,201,069,294, subject to an upward or downward variance of no
more than 5%.                                                                   

The initial aggregate principal balance of the certificates has the following   
composition:                                                                    

the senior certificates comprise                              
approximately 90.75% of the principal                         
balance of the mortgage loans;                                

the Class B-1 through Class B-9                               
Certificates comprise approximately 6.95%                     
of the principal balance of the mortgage                      
loans; and                                                    

the privately offered Class B-10,                             
Class B-11, Class B-12 and Class B-13                         
Certificates comprise approximately 2.30%                     
of the principal balance of the mortgage                      
loans.                                                        

DISTRIBUTIONS ON THE CERTIFICATES                                               

MONTHLY DISTRIBUTIONS                                                           

Each month, the trustee, Deutsche Bank National Trust Company, will make        
distributions of interest and/or principal to the holders of the certificates.  
Distributions will be made on the 25th day of each month, or if the 25th day is 
not a business day, on the next business day. The first distribution date will  
be September 26, 2005.                                                          

Source of Payments. The mortgagors pay their interest and principal during the  
month to Washington Mutual Bank, as servicer. Each month, the servicer subtracts
its servicing fee and sends the remainder to the trustee. On the distribution   
date for that month, the trustee distributes that remaining amount to the       
holders of the certificates in the order described in 'Description of the       
Certificates -- Priority of Distributions' in this prospectus supplement.       

Advances. For any month, if the servicer receives a payment on a mortgage loan  
that is less than the minimum monthly payment due or if no payment is received  
at all, the servicer will advance its own funds to cover the difference between 
the minimum monthly payment due and the amount actually received by the         
servicer. However, the servicer will not be required to make advances if it     
determines that those advances will not be recoverable from future payments or  
collections on that mortgage loan. See 'Description of the Certificates --      
Advances' in this prospectus supplement.                                        

DISTRIBUTIONS OF INTEREST                                                       

Each class of offered certificates will accrue interest. On each distribution   
date interest will be distributed to these classes in the order described in    
'Description of the Certificates -- Priority of Distributions' in this          
prospectus supplement.                                                          

Solely for purposes of calculating distributions of principal and interest and  
the allocation of losses realized on the mortgage loans, the Class X            
Certificates will be deemed to be comprised of an interest-only component and a 
principal-only component. The Class X interest-only component will have a       
notional amount (as described below). Interest will accrue on the Class X       
notional amount. The Class X interest-only component will                       

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not have a principal balance and principal will not be payable with respect to  
the Class X notional amount. The Class X principal-only component will have a   
principal balance, which initially will equal zero. Interest will not accrue on 
the Class X principal-only component.                                           

Interest to be distributed on the certificates (or added to the principal       
balance of the certificates in the form of 'net negative amortization,' as      
described below) on any distribution date will consist of accrued and unpaid    
interest as of previous distribution dates and interest accrued during the      
period beginning on the 25th day of the preceding calendar month and ending on  
the 24th day of the month of that distribution date, except for the Class X     
Certificates, which accrue interest on their notional amount during the         
preceding calendar month. Interest on the Class A Certificates will be          
calculated based on the actual number of days in the certificate accrual period 
and assuming a 360 day year. Interest on the Class X and subordinate            
certificates will be calculated based on a year consisting of twelve thirty-day 
months.                                                                         

In the event that an increase in the index causes interest to accrue on a       
mortgage loan for a given month in excess of the monthly payment for that       
mortgage loan, the excess interest will be added to the outstanding principal   
balance of that mortgage loan in the form of 'negative amortization.' For any   
distribution date, the excess, if any, of (i) the aggregate amount of negative  
amortization with respect to all mortgage loans for the calendar month prior to 
that distribution date, over (ii) the aggregate amount of prepayments in full   
and partial prepayments received with respect to all mortgage loans during the  
related prepayment period (the 'NET NEGATIVE AMORTIZATION'), will be deducted   
from interest payable to the certificates as described in 'Description of the   
Certificates -- Distributions of Interest' in this prospectus supplement. The   
amount deducted from the interest payable to each class of certificates will be 
added to the principal balance of that class.                                   

It is possible that, on any given distribution date, there will be insufficient 
payments from the mortgage loans to make the interest distributions (net of any 
Net Negative Amortization deducted from interest payable) described in this     
prospectus supplement. If the servicer does not advance its own funds, because  
it determines that the advance would be nonrecoverable, some certificates, most 
likely the subordinate certificates, may not receive the full amount of accrued 
interest to which they are entitled. If this happens, those certificates will be
entitled to receive any shortfall in interest distributions on future           
distribution dates in the same priority as their distribution of current        
interest. However, there will be no extra interest paid on that shortfall.      

The amount of interest each class of Class A Certificates accrues during each   
certificate accrual period will equal a ratio, the numerator of which is the    
actual number of days in that accrual period and the denominator of which is    
360, multiplied by the annual certificate interest rate in effect for that      
accrual period for that class and multiplied by the related class principal     
balance. The amount of interest the Class X Certificates and each class of      
subordinate certificates accrues during each certificate accrual period will    
equal 1/12th of the annual certificate interest rate in effect for that accrual 
period for that class multiplied by (i) in the case of the certificates other   
than the Class X Certificates, the related class principal balance and (ii) in  
the case of the Class X Certificates, the Class X notional amount. The principal
balance or notional amount used for this calculation on the first distribution  
date will be the applicable principal balance or notional amount as of          
August 25, 2005, which is the closing date. The principal balance used for this 
calculation on each distribution date thereafter will be the applicable         
principal balance immediately after the preceding distribution date. The annual 
certificate interest rate for each class of offered certificates is described on
pages S-5 to S-9 of this prospectus supplement. For a description of how the    
Class X notional amount is determined, see 'Description of the Certificates --  
Distributions of Interest' in this prospectus supplement.                       

No interest will accrue on the Class X principal-only component or on the       
Class PPP Certificates.                                                         

LIBOR Certificates. The certificate interest rates for the Class A and Class B  
Certificates adjust monthly based on the average of quotations of the London    
Interbank Offered Rate for one-month U.S. dollar deposits, or LIBOR, as         
described in 'Description of the Certificates -- Calculation of LIBOR' in this  
prospectus supplement. The formulas for the calculation of the certificate      
interest rates for these LIBOR Certificates appear                              

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in the notes to the table on page S-4 of this prospectus supplement. However,   
the certificate interest rate for (i) the Class A-1A, Class A-1B1, Class A-1B2, 
Class A-1B3, Class A-1C1, Class A-1C2, Class A-1C3 and Class A-1C4 Certificates 
may not exceed the lesser of (a) the Adjusted Weighted Average Pass-Through Rate
and (b) 10.50% and (ii) the Class B-1, Class B-2, Class B-3, Class B-4,         
Class B-5, Class B-6, Class B-7, Class B-8 and Class B-9 Certificates may not   
exceed the lesser of (a) the Weighted Average Pass-Through Rate and (b) 10.50%. 

The Class A Certificates and the subordinate certificates may receive as        
interest, in addition to interest accrued at their certificate interest rates,  
carryover shortfall amounts, as described in 'Description of the                
Certificates -- Distributions of Interest -- Carryover Shortfall Amount.'       

Amounts to be distributed to the Class X Certificates in respect of accrued     
interest on their notional amount on any distribution date may be reduced by    
carryover shortfall amounts payable to (i) the Class A Certificates for such    
distribution date not covered by amounts payable pursuant to the yield          
maintenance agreement and (ii) the Class B Certificates.                        

COMPENSATING INTEREST AND INTEREST SHORTFALLS                                   

Prepayments in Full. When mortgagors make prepayments in full, they need not pay
a full month's interest. Instead, they are required to pay interest only to the 
date of their prepayment. To compensate certificateholders for the shortfall in 
interest this causes, the servicer may pay compensating interest to the         
certificateholders out of the servicing fee it collects, as well as from certain
other sources. For a description of how compensating interest is allocated among
the certificates as well as important limitations on the amount of compensating 
interest that will be allocated among the certificates, see 'Description of the 
Certificates -- Distributions of Interest -- Compensating Interest' and 'Yield  
and Prepayment Considerations' in this prospectus supplement.                   

Partial Prepayments. When mortgagors make partial prepayments, they do not pay  
interest on the amount of that prepayment. Certificateholders will receive no   
compensating interest to compensate them for the shortfall in interest this     
causes.                                                                         

DISTRIBUTIONS OF PRINCIPAL                                                      

General. As the mortgagors pay principal on the mortgage loans, that principal  
is passed on to the holders of the certificates, as applicable.                 

The Class A Certificates and the Class X principal-only component (in the event 
Net Negative Amortization has been allocated to the Class X Certificates), in   
the aggregate, generally will receive their pro rata share of scheduled         
principal payments received on the mortgage loans on each distribution date. In 
addition, unless credit enhancement to the Class A and Class X Certificates has 
reached a specified level and the delinquencies and losses on the mortgage loans
do not exceed specified limits, the Class A Certificates and Class X            
principal-only component, in the aggregate, generally will receive 100% of all  
principal prepayments received on the mortgage loans, net of any portion thereof
applied to reduce negative amortization, until the tenth anniversary of the     
first distribution date, after which they will receive a disproportionately     
large, but decreasing, share of principal prepayments.                          

On each distribution date, a portion of the principal received or advanced on   
the mortgage loans will be distributed, first, to the Class A Certificates and, 
second, to the Class X Certificates, as described in 'Description of the        
Certificates -- Distributions of Principal -- Senior Principal Distribution     
Amount' in this prospectus supplement. HOWEVER, NOT ALL OF THESE CERTIFICATES   
WILL RECEIVE PRINCIPAL ON EACH DISTRIBUTION DATE. SEE APPENDIX A FOR A TABLE    
SHOWING, FOR EACH CLASS OF CERTIFICATES (OTHER THAN THE CLASS X CERTIFICATES),  
THE RATE OF RETURN OF PRINCIPAL THAT WOULD RESULT FROM DIFFERENT RATES OF       
PREPAYMENTS ON THE MORTGAGE LOANS. However, if the subordinate certificates are 
no longer outstanding, then the Class A and Class X Certificates will not       
receive principal in the order of priority described in 'Description of the     
Certificates -- Distributions of Principal -- Senior Principal Distribution     
Amount' in this prospectus supplement. Instead, each of these classes of        
certificates will generally receive principal pro rata according to its class   
principal balance. IF THE SUBORDINATE CERTIFICATES ARE OUTSTANDING, THE CLASS X 
PRINCIPAL-ONLY COMPONENT WILL NOT RECEIVE ANY DISTRIBUTIONS OF PRINCIPAL UNTIL  
THE PRINCIPAL BALANCES OF THE CLASS A CERTIFICATES HAVE EACH BEEN REDUCED TO    
ZERO.                                                                           

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Class B Certificates. On each distribution date, the Class B-1, Class B-2,      
Class B-3, Class B-4, Class B-5, Class B-6, Class B-7, Class B-8, Class B-9,    
Class B-10, Class B-11, Class B-12 and Class B-13 Certificates will be entitled 
to receive a portion of the scheduled principal received or advanced on the     
mortgage loans, pro rata, according to their respective class principal         
balances. Unless credit enhancement to the senior certificates has reached a    
specified level and the delinquencies and losses on the mortgage loans do not   
exceed specified limits, the Class B Certificates generally will receive a      
portion of the principal prepayments on the mortgage loans only on and after the
tenth anniversary of the first distribution date. However, under certain        
conditions described in this prospectus supplement under 'Description of the    
Certificates -- Priority of Distributions,' the amount of principal prepayments 
otherwise distributable to some classes of Class B Certificates will instead be 
paid to other classes of these certificates with a higher priority.             

Priority of Principal Distributions. Each class of certificates, receives its   
principal entitlements in the order described in 'Description of the            
Certificates -- Priority of Distributions' in this prospectus supplement. It is 
possible that, on any given distribution date, there will be insufficient       
payments from the mortgage loans to make the principal distributions described  
in this prospectus supplement. As a result, some certificates, most likely the  
subordinate certificates, may not receive the full amount of principal          
distributions to which they are entitled.                                       

The Class X Certificates will not receive any distributions of principal in     
respect of the Class X notional amount.                                         

The Class PPP Certificates will not have a principal balance and will not       
receive any distributions of principal.                                         

For a more detailed description of how distributions of principal will be       
allocated among the various classes of certificates, see 'Description of the    
Certificates -- Distributions of Principal' in this prospectus supplement.      

CREDIT ENHANCEMENTS                                                             

Subordination. The senior certificates will receive distributions of interest   
and principal to which they are entitled before the subordinate certificates are
entitled to receive distributions of interest or principal. This provides credit
enhancement to the senior certificates. In a similar fashion, each class of     
subordinate certificates will provide credit enhancement to all other           
subordinate certificates with lower numerical class designations.               

Shifting of Interests. The senior certificates generally will receive their pro 
rata share of scheduled principal payments on each distribution date. In        
addition, unless credit enhancement to the senior certificates has reached a    
specified level and the delinquencies and losses on the mortgage loans do not   
exceed specified limits, the senior certificates in the aggregate will receive  
100% of all principal prepayments received on the mortgage loans, net of any    
portion thereof applied to reduce negative amortization, until the tenth        
anniversary of the first distribution date. During the next four years the      
senior certificates in the aggregate will generally receive a disproportionately
large, but decreasing, share of principal prepayments. This will result in a    
quicker return of principal to the senior certificates and increases the        
likelihood that holders of the senior certificates will be paid the full amount 
of principal to which they are entitled. For a more detailed description of how 
principal prepayments are allocated among the senior certificates and the       
subordinate certificates, see 'Description of the Certificates -- Principal     
Prepayments' in this prospectus supplement.                                     

YIELD MAINTENANCE AGREEMENT                                                     

The holders of the Class A Certificates will have the benefit of payments, if   
any, from Bear Stearns Financial Products Inc. pursuant to a yield maintenance  
agreement. The yield maintenance agreement is intended to partially mitigate the
risk to the Class A Certificates that the lesser of (i) LIBOR plus the related  
margin and (ii) 10.50% will exceed the Adjusted Weighted Average Pass-Through   
Rate. Payments, if any, made pursuant to the yield maintenance agreement will   
start on the distribution date in October 2005 and will terminate after the     
distribution date in February 2014. The holders of the Class B Certificates will
not have the benefit of payments made pursuant to the yield maintenance         
agreement. See 'Description of the Certificates -- Carryover Shortfall Amounts' 
in this prospectus supplement.                                                  

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ALLOCATION OF LOSSES                                                            

Realized Losses. A loss is realized on a mortgage loan when the servicer        
determines that it has received all amounts it expects to recover for that      
mortgage loan and the amounts are less than the outstanding principal balance of
the mortgage loan and its accrued and unpaid interest. LOSSES WILL BE ALLOCATED 
TO THE CERTIFICATES BY DEDUCTING THE LOSSES FROM THE PRINCIPAL BALANCE OF THE   
CERTIFICATES WITHOUT MAKING ANY PAYMENTS TO THE CERTIFICATEHOLDERS. The amount  
of losses will be allocated to the most junior class of subordinate certificates
then outstanding. Losses will be allocated to the senior certificates other than
the Class R Certificates only after the principal balances of all of the        
subordinate certificates have been reduced to zero. After the principal balances
of all of the subordinate certificates have been reduced to zero, any loss with 
respect to a mortgage loan will be allocated to the Class A Certificates and the
Class X principal-only component, pro rata, until their respective class        
principal or component, as applicable, balances have been reduced to zero       
provided, however, that losses that would otherwise be allocated to the Class   
A-1A Certificates will be allocated (i) first, to the Class A-1C1, Class A-1C2, 
Class A-1C3 and Class A-1C4 Certificates, pro rata, until their respective class
principal balances have each been reduced to zero and (ii) second, to the       
Class A-1B1, Class A-1B2 and Class A-1B3 Certificates, pro rata, until their    
respective class principal balances have each been reduced to zero; and         
provided, further, that losses that would otherwise be allocated to the Class   
A-1B1, Class A-1B2 or Class A-1B3 Certificates will be allocated to the Class   
A-1C1, Class A-1C2, Class A-1C3 and Class A-1C4 Certificates, pro rata, until   
their respective class principal balances have each been reduced to zero.       

YIELD CONSIDERATIONS                                                            

The yield to maturity on each class of certificates will depend upon, among     
other things:                                                                   

the price at which the certificates are                       
purchased;                                                    

the amount payable to that class as                           
interest;                                                     

the rate of prepayments (including                            
liquidations) on the mortgage loans; and                      

whether the optional termination of the                       
Trust occurs.                                                 

The Class X Certificates, which generally receive only distributions of interest
(except for amounts added to their component principal balance as a result of   
Net Negative Amortization, which is then distributed to the Class X Certificates
as principal), will be especially sensitive to the rate of prepayments. For a   
discussion of special yield considerations applicable to these certificates, see
'Risk Factors' and 'Yield and Prepayment Considerations -- Yield Considerations 
with Respect to the Class X Certificates' in this prospectus supplement.        

See 'Yield and Prepayment Considerations' in this prospectus supplement.        

BOOK-ENTRY REGISTRATION                                                         

In general, the offered certificates, other than the Class R Certificates, will 
be available only in book-entry form through the facilities of The Depository   
Trust Company, Euroclear and Clearstream. See 'Description of the               
Certificates -- Book-Entry Registration' in this prospectus supplement.         

DENOMINATIONS                                                                   

The offered certificates, other than the Class X and Class R Certificates, are  
offered in minimum denominations of $25,000 each and multiples of $1 in excess  
of $25,000.                                                                     

The Class X Certificates are offered in minimum denominations of $100,000       
initial class notional amount each and multiples of $1 in excess of $100,000.   

The Class R Certificates will have an initial class principal balance of $100   
and will be offered in a single certificate that represents a 99.99% interest in
its class.                                                                      

LEGAL INVESTMENT                                                                

As of the date of their issuance, all of the offered certificates, other than   
the Class B-4, Class B-5, Class B-6, Class B-7, Class B-8 and Class B-9         
Certificates, will be 'mortgage related securities' for purposes of the         
Secondary Mortgage Market Enhancement Act of 1984. See 'Certain Legal Investment
Aspects' in this prospectus supplement for important information concerning     
possible restrictions on ownership of the offered certificates by regulated     
institutions. You should consult your own legal advisors in determining whether 
and to                                                                          

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what extent the offered certificates constitute legal investments for you.      

ERISA CONSIDERATIONS                                                            

Subject to important considerations described under 'ERISA Considerations' in   
this prospectus supplement and in the accompanying prospectus, the offered      
certificates, other than the Class R Certificates, will be eligible for purchase
by persons investing assets of employee benefit plans or individual retirement  
accounts. See 'ERISA Considerations' in this prospectus supplement and in the   
accompanying prospectus.                                                        

FEDERAL INCOME TAX CONSEQUENCES                                                 

For federal income tax purposes, the servicer will cause two REMIC elections to 
be made with respect to the Trust (exclusive of the yield maintenance           
agreement). The certificates, other than the Class R and Class PPP Certificates,
will represent ownership of REMIC regular interests, coupled with, in the case  
of the Class A Certificates, an interest in a yield maintenance agreement, and  
will generally be treated as representing ownership of debt for federal income  
tax purposes. You will be required to include in income all interest and        
original issue discount on these certificates in accordance with the accrual    
method of accounting regardless of your usual methods of accounting. For federal
income tax purposes, the Class R Certificates will represent ownership of the   
REMIC residual interest. The Class PPP Certificates will not represent an       
interest in any REMIC.                                                          

For further information regarding the federal income tax consequences of        
investing in the offered certificates, including important information regarding
the tax treatment of the Class R Certificates, see 'Certain Federal Income Tax  
Consequences' in this prospectus supplement and in the accompanying prospectus. 

RATINGS                                                                         

The offered certificates are required to receive the ratings from Standard &    
Poor's Ratings Services, a division of The McGraw-Hill Companies, Inc., and     
Moody's Investors Service, Inc. indicated under 'Certificate Ratings' in this   
prospectus supplement. The ratings on the offered certificates address the      
likelihood of the receipt by holders of the offered certificates of all         
distributions on the underlying mortgage loans to which they are entitled. They 
do not address the likely actual rate of prepayments. The rate of prepayments,  
if different than originally anticipated, could adversely affect the yield      
realized by holders of the offered certificates or cause the holders of the     
Class X Certificates to fail to recover their initial investment.               

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RISK FACTORS

   THE OFFERED CERTIFICATES ARE NOT SUITABLE INVESTMENTS FOR ALL INVESTORS. IN
PARTICULAR, YOU SHOULD NOT PURCHASE ANY CLASS OF OFFERED CERTIFICATES UNLESS YOU
UNDERSTAND AND ARE ABLE TO BEAR THE PREPAYMENT, CREDIT, LIQUIDITY AND MARKET    
RISKS ASSOCIATED WITH THAT CLASS.                                               

    THE OFFERED CERTIFICATES ARE COMPLEX SECURITIES AND IT IS IMPORTANT THAT YOU
POSSESS, EITHER ALONE OR TOGETHER WITH AN INVESTMENT ADVISOR, THE EXPERTISE     
NECESSARY TO EVALUATE THE INFORMATION CONTAINED IN THIS PROSPECTUS SUPPLEMENT   
AND THE ACCOMPANYING PROSPECTUS IN THE CONTEXT OF YOUR FINANCIAL SITUATION.     

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THERE IS NO GUARANTEE THAT YOU WILL RECEIVE     As the mortgagors make payments of interest and    
PRINCIPAL PAYMENTS ON YOUR CERTIFICATES AT ANY  principal on their mortgage loans, you will receive
SPECIFIC RATE OR ON ANY SPECIFIC DATES          payments. Because the mortgagors are free to make  
                                                those payments faster than scheduled, you may      
                                                receive distributions faster than you expected.    
                                                There is no guarantee that you will receive        
                                                principal payments on your certificates at any     
                                                specific rate or on any specific dates.            

THE YIELD ON YOUR CERTIFICATES IS DIRECTLY      The yield to maturity on your certificates is      
RELATED TO THE PREPAYMENT RATE ON THE MORTGAGE  directly related to the rate at which the          
LOANS                                           mortgagors pay principal on the mortgage loans.    
                                                Principal payments on the mortgage loans may be in 
                                                the following forms:                               

                                                   scheduled principal payments; and               

                                                   principal prepayments, which consist of:        

                                                      prepayments in full on a mortgage loan;      

                                                      partial prepayments on a mortgage loan; and  

                                                      liquidation principal, which is the principal
                                                      recovered after foreclosing on or otherwise  
                                                      liquidating a defaulted mortgage loan.       

                                                Each mortgage loan in the Trust is an              
                                                adjustable-rate mortgage loan. In general, each    
                                                mortgage loan has an initial fixed-rate period of  
                                                one, two, three or twelve months and during the    
                                                initial fixed-rate period, if prevailing mortgage  
                                                interest rates decline significantly below the     
                                                mortgage interest rates on the mortgage loans in   
                                                the Trust, the prepayment rate may increase.       

                                                As of August 1, 2005, approximately 73.5% (by      
                                                aggregate principal balance) of the mortgage loans 
                                                impose penalties for early prepayments in full (but
                                                do not impose penalties for partial prepayments)   
                                                received on or before the first anniversary of the 
                                                origination of the mortgage loan. As of August 1,  
                                                2005, approximately 8.1% (by aggregate principal   
                                                balance) of the mortgage loans impose penalties for
                                                early prepayments in full (but do not impose       
                                                penalties for partial prepayments) received on or  
                                                before the third anniversary of the origination of 
                                                the mortgage loan. As of August 1, 2005,           
                                                approximately 1.3% (by aggregate principal balance)
                                                of the mortgage loans impose penalties for early   
                                                prepayments in full, and for partial prepayments in
                                                the event that aggregate partial prepayments made  
                                                during a 12-month period exceed 20% of the original
                                                principal balance. Those prepayment penalties are  
                                                in effect for 30 months after the origination of   
                                                those mortgage loans. The amount of the applicable 
                                                prepayment penalty,                                

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to the extent permitted by applicable law, is as   
provided in the related mortgage note. Such        
prepayment premiums may discourage mortgagors from 
prepaying their mortgage loans during the period   
such prepayment penalties are in effect and,       
accordingly, thereby affect the rate of prepayment 
of such mortgage loans even in a declining interest
rate environment. All prepayment penalty payments  
remitted to the trust with respect to voluntary    
full prepayments will be distributed to the holders
of the Class PPP Certificates. The holders of the  
Class PPP Certificates will not receive any        
prepayment penalty payment remitted to the trust   
with respect to voluntary partial prepayments; each
such payment will be retained by the servicer as   
additional servicing compensation. No prepayment   
penalty payments will be available for distribution
to holders of the other classes of certificates.   
Notwithstanding the foregoing, no penalties are    
imposed (i) in some cases where the mortgagor sells
the mortgaged property and obtains a new mortgage  
loan originated and serviced by Washington Mutual  
Bank to purchase another property, provided that   
the prepayment is made no earlier than one year    
after origination, (ii) in some cases where the    
mortgagor refinances the mortgage loan with a new  
mortgage loan originated and serviced by Washington
Mutual Bank, provided that 90 days or less remain  
in the prepayment penalty term, or (iii) for       
prepayments of accrued but unpaid interest that has
been added to principal as a result of negative    
amortization.                                      

See 'Description of the Mortgage Pool' in this     
prospectus supplement for a description of         
prepayment penalties imposed on the mortgage loans.
General economic conditions and homeowner mobility 
will also affect the prepayment rate. See 'Yield   
and Prepayment Considerations' in this prospectus  
supplement and 'Maturity, Average Life and         
Prepayment Assumptions' in the prospectus. The     
prepayment rate may affect the yield on all of the 
offered certificates. However, if you have         
purchased a Class X Certificate, the prepayment    
rate will be especially important to you.          

Washington Mutual Mortgage Securities Corp. filed  
with the Securities and Exchange Commission on     
August 8, 2005 limited historical information      
concerning principal prepayment experience of      
mortgage loans of the general type included in the 
trust; however, the prepayment experience with     
respect to the specific mortgage loans included in 
the trust may differ significantly from the        
historical experience of this type of mortgage     
loan, and such differences may be substantial due  
to the inclusion in the historical information of  
mortgage loans with wider ranges of principal      
balances and credit scores than those in the       
mortgage loans included in the trust, among other  
possible reasons. If prevailing mortgage interest  
rates fall significantly, adjustable-rate mortgage 
loans could be subject to higher prepayment rates  
than if prevailing mortgage interest rates remain  
constant because the                               

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                                                  availability of fixed-rate mortgage loans at       
                                                  competitive interest rates may encourage mortgagors
                                                  to refinance their mortgage loans to 'lock in'     
                                                  lower fixed interest rates. The features of        
                                                  adjustable-rate mortgage loan programs during the  
                                                  past years have varied significantly in response to
                                                  market conditions including the interest-rate      
                                                  environment, consumer demand, regulatory           
                                                  restrictions and other factors. The lack of        
                                                  uniformity of the terms and provisions of those    
                                                  adjustable-rate mortgage loan programs have made it
                                                  impracticable to compile meaningful comparative    
                                                  data on prepayment rates and, accordingly, we      
                                                  cannot assure you as to the rate of prepayments on 
                                                  the mortgage loans in stable or changing interest  
                                                  rate environments.                                 

                                                  From time to time, Washington Mutual Bank may      
                                                  implement programs to solicit mortgagors of        
                                                  qualifying mortgage loans that they service for    
                                                  refinance, including mortgage loans underlying the 
                                                  certificates. While those programs will not        
                                                  specifically target the mortgage loans underlying  
                                                  the certificates for refinance, they may have the  
                                                  effect of accelerating the prepayment rate of those
                                                  mortgage loans, which would adversely affect the   
                                                  yield on all classes of certificates purchased at a
                                                  premium, particularly the Class X Certificates.    

THE YIELD ON YOUR CERTIFICATES MAY BE LIMITED BY  Each mortgage loan has a maximum mortgage interest 
MAXIMUM MORTGAGE INTEREST RATES                   rate, which may prevent the mortgage interest rate 
                                                  on a mortgage loan from increasing, despite        
                                                  prevailing market interest rates. As a result, the 
                                                  yield on your certificates may be adversely        
                                                  affected.                                          

IF THE INDEX IS REPLACED, THE MORTGAGE LOAN       If One-Year MTA is no longer available, the        
MARGINS MAY BE ADJUSTED                           servicer will choose a new index for the mortgage  
                                                  loans that is based on comparable information. When
                                                  the servicer chooses a new index, it will increase 
                                                  or decrease the margin for each mortgage loan by   
                                                  the difference between the average of the old index
                                                  for the final three years it was in effect and the 
                                                  average of the replacement index for the most      
                                                  recent three years. The new margin for each        
                                                  mortgage loan will be rounded up as provided in the
                                                  related mortgage note.                             

AN OPTIONAL TERMINATION OF THE TRUST MAY          When the aggregate principal balance of the        
ADVERSELY AFFECT THE OFFERED CERTIFICATES         mortgage loans owned by the Trust has been reduced 
                                                  to less than 10% of that balance as of August 1,   
                                                  2005, the servicer may purchase all of the mortgage
                                                  loans owned by the Trust, which will terminate the 
                                                  Trust. See 'Description of the Certificates --     
                                                  Optional Termination of the Trust' in this         
                                                  prospectus supplement and 'Description of the      
                                                  Certificates -- Termination' in the prospectus. If 
                                                  this happens, the purchase price paid by the       
                                                  servicer will be passed through to the             
                                                  certificateholders. This would have the same effect
                                                  as if all of the remaining mortgagors made         
                                                  prepayments in full on the last day of the month.  
                                                  Since the Class X Certificates generally receive   
                                                  only distributions of interest (except for interest
                                                  added to their component principal balance as a    
                                                  result of the allocation of any Net Negative       
                                                  Amortization, which is then distributed to the     
                                                  Class X Certificates as principal), an optional    
                                                  termination                                        

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                                                 of the Trust would adversely affect holders of     
                                                 those certificates. In addition, any other class of
                                                 certificates purchased at a premium could be       
                                                 adversely affected by an optional termination of   
                                                 the Trust.                                         

EVEN IF THE INDEX REMAINS CONSTANT, THE MINIMUM  Although none of the mortgage loans were in their  
MONTHLY PAYMENT ON THE MORTGAGE LOANS MAY BE     fixed- rate period as of the Cut-Off Date, the     
LESS THAN THE ACTUAL INTEREST DUE FOR THE FIRST  minimum monthly payment for the entire first year  
FIVE YEARS, INCREASING THE LIKELIHOOD OF         following origination of the mortgage loan reflects
NEGATIVE AMORTIZATION DURING THE EARLY YEARS OF  the fixed rate in effect during that initial       
THE MORTGAGE LOANS                               fixed-rate period, which will generally be lower   
                                                 than the fully indexed rate in effect at any time  
                                                 during the first year. Therefore, even if the index
                                                 does not increase, the minimum monthly payment     
                                                 during the first five years of the mortgage loan   
                                                 may not be enough to pay the amount of interest due
                                                 on the mortgage loan at the fully indexed rate,    
                                                 which is calculated based on the sum of the index  
                                                 and the margin.                                    

                                                 If the mortgagor chooses to pay the minimum monthly
                                                 payment rather than the other higher payment       
                                                 options, this will lead to an increase in the      
                                                 outstanding principal balance of the mortgage loan 
                                                 in the form of negative amortization. Even after   
                                                 the first year, when the minimum monthly payment   
                                                 may increase by 7.5%, this adjustment may not be   
                                                 enough to raise the minimum monthly payment to the 
                                                 amount necessary to pay the interest due on the    
                                                 mortgage loan based on the sum of the index and the
                                                 margin in effect during the following year. If the 
                                                 new minimum monthly payment is still less than the 
                                                 fully indexed rate during the following year, there
                                                 will continue to be negative amortization if the   
                                                 mortgagor chooses to pay the minimum monthly       
                                                 payment.                                           

                                                 Therefore the effect of the initial fixed rate at  
                                                 the beginning of the life of the mortgage loan may 
                                                 continue to cause the minimum monthly payment to be
                                                 less than the monthly interest due on the mortgage 
                                                 loan until the fifth anniversary of the first due  
                                                 date when the minimum monthly payment will be reset
                                                 to a fully-amortizing payment regardless of the    
                                                 7.5% limit.                                        

NEGATIVE AMORTIZATION MAY INCREASE LOSSES        When interest due on a mortgage loan is added to   
APPLIED TO YOUR CERTIFICATES                     the principal balance of the mortgage loan through 
                                                 negative amortization, the mortgaged property      
                                                 provides proportionally less security for the      
                                                 repayment of the mortgage loan. Therefore, if the  
                                                 mortgagor defaults on the mortgage loan there is a 
                                                 greater likelihood that a loss will be incurred    
                                                 upon the liquidation of the mortgaged property.    
                                                 Furthermore, the loss will be larger than would    
                                                 otherwise have been recognized in the absence of   
                                                 negative amortization. Certificateholders will bear
                                                 these losses as described in 'Description of the   
                                                 Certificates -- Subordination and Allocation of    
                                                 Losses' in this prospectus supplement.             

ALLOCATIONS OF NET NEGATIVE AMORTIZATION MAY     For any given month in which interest due on       
AFFECT YOUR YIELD                                mortgage loans is added to the principal balance of
                                                 those mortgage loans through negative amortization,
                                                 the reduction in                                   

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                                                  interest distributions resulting from such negative
                                                  amortization may be offset, in part, by applying   
                                                  certain principal prepayments received on the      
                                                  mortgage loans to interest distributions on the    
                                                  certificates. For any distribution date, the       
                                                  excess, if any, of negative amortization on the    
                                                  mortgage loans over the principal prepayments      
                                                  received on the mortgage loans, or Net Negative    
                                                  Amortization, will be deducted from the interest   
                                                  payable to the certificates as described in        
                                                  'Description of the Certificates -- Distributions  
                                                  of Interest' in this prospectus supplement. The    
                                                  amount of the reduction of accrued interest        
                                                  distributable to each class of certificates        
                                                  attributable to Net Negative Amortization will be  
                                                  added to the class principal balance of that class.
                                                  The increase in the class principal balance of any 
                                                  class of certificates will have the effect of      
                                                  increasing the applicable investors' exposure to   
                                                  realized losses on the mortgage loans. In addition,
                                                  because the allocation of principal prepayments    
                                                  between the senior and subordinate certificates may
                                                  be determined based on the relationship between the
                                                  aggregate class principal balance of the senior    
                                                  certificates and the aggregate class principal     
                                                  balance of the subordinate certificates, this      
                                                  method of allocating Net Negative Amortization may 
                                                  affect the rate and timing of distributions of     
                                                  principal prepayments among the classes of         
                                                  certificates. See 'Description of the              
                                                  Certificates -- Principal Prepayments' in this     
                                                  prospectus supplement.                             

A DECLINING INTEREST RATE ENVIRONMENT MAY         If a decline in the index causes the interest due  
ACCELERATE THE PAYMENT ON YOUR CERTIFICATES       on a mortgage loan to be less than the current     
                                                  monthly payment, the amount of that difference will
                                                  be subtracted from the outstanding principal       
                                                  balance of the mortgage loan and remitted to the   
                                                  certificateholders as principal distributions on   
                                                  the certificates. To the extent that these amounts 
                                                  are greater than the principal payments on the     
                                                  mortgage loans you anticipated, the principal      
                                                  balance of your certificates may be reduced to zero
                                                  sooner than you expected.                          

POSSESSION BY A SUBSEQUENT PURCHASER OR CREDITOR  The trustee will not have physical possession of   
OF THE MORTGAGE NOTES AND MORTGAGES COULD DEFEAT  the mortgage notes and mortgages related to the    
THE INTERESTS OF THE TRUST IN THE MORTGAGE NOTES  mortgage loans owned by the Trust. In addition, the
AND MORTGAGES                                     trustee will not conduct any independent review or 
                                                  examination of the related mortgage files. Instead,
                                                  to facilitate servicing and reduce administrative  
                                                  costs, Washington Mutual Bank fsb, a wholly-owned  
                                                  subsidiary of Washington Mutual Bank, the servicer 
                                                  of the mortgage loans, will retain possession of   
                                                  and will review the mortgage notes and mortgages as
                                                  custodian for the Trust and financing statements   
                                                  will be filed evidencing the Trust's interest in   
                                                  the mortgage loans. The mortgage notes will not be 
                                                  endorsed to the Trust and no assignment of the     
                                                  mortgages to the Trust will be prepared.           
                                                  Furthermore, the mortgage notes and mortgages will 
                                                  not be stamped or otherwise marked to reflect the  
                                                  assignment to Washington Mutual Mortgage Securities
                                                  Corp. and then to the Trust. If a subsequent       
                                                  purchaser or creditor were able to take physical   
                                                  possession of the mortgage notes and mortgages     
                                                  without knowledge of that assignment, the          

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                                                interests of the Trust in the mortgage notes and   
                                                mortgages could be defeated. In that event,        
                                                distributions to certificateholders may be         
                                                adversely affected.                                

RAPID PREPAYMENTS WILL REDUCE THE YIELD ON THE  The Class X Certificates generally receive only    
CLASS X CERTIFICATES                            distributions of interest (except for amounts added
                                                to their component principal balance as a result of
                                                Net Negative Amortization, which is then           
                                                distributed to the Class X Certificates as         
                                                principal). The yield to maturity on the Class X   
                                                Certificates will be extremely sensitive to the    
                                                level of prepayments on the mortgage loans. The    
                                                faster that the mortgage loans prepay, the less    
                                                interest the Class X Certificates will receive.    

                                                The yield to maturity on the Class X Certificates  
                                                will be especially sensitive to the level of       
                                                prepayments on the mortgage loans with higher      
                                                interest rates. For each distribution date,        
                                                interest accrues on the notional amount of the     
                                                Class X Certificates at an annual certificate      
                                                interest rate equal to the excess, if any, of      
                                                (x) the Weighted Average Pass-Through Rate over    
                                                (y) the rate described in clause (y) of note (10)  
                                                to the table on page S-4 of this prospectus        
                                                supplement. Consequently, the higher the interest  
                                                rates on the mortgage loans that prepay, the less  
                                                interest will accrue on the notional amount of the 
                                                Class X Certificates and under certain prepayment  
                                                scenarios, the Class X Certificates may not accrue 
                                                any interest. If mortgage interest rates decline,  
                                                the higher interest rate mortgage loans are more   
                                                likely to be refinanced, and, therefore,           
                                                prepayments in full on these mortgage loans are    
                                                more likely to occur.                              

                                                You should fully consider the risks associated with
                                                an investment in the Class X Certificates. If the  
                                                mortgage loans prepay faster than expected or if   
                                                the Trust is terminated earlier than expected, you 
                                                may not fully recover your initial investment. See 
                                                'Yield and Prepayment Considerations -- Yield      
                                                Considerations with Respect to the Class X         
                                                Certificates' in this prospectus supplement for a  
                                                table showing expected yields at different         
                                                prepayment rates.                                  

CHANGES TO THE CERTIFICATE MARGINS WILL REDUCE  The certificate margins for the Class A and        
THE YIELD ON THE CLASS X CERTIFICATES           Class B Certificates will increase after the       
                                                Clean-Up Call Option Date to the amount specified  
                                                in the notes to the table on page S-4 of this      
                                                prospectus supplement. Consequently, the           
                                                certificate interest rate for the Class X          
                                                Certificates will be reduced after that date.      

THE CLASS A AND CLASS B CERTIFICATES WILL BE    The Class A Certificates will receive interest at a
SENSITIVE TO CHANGES IN LIBOR                   certificate interest rate equal to the least of    
                                                (x) the Adjusted Weighted Average Pass-Through     
                                                Rate, (y) LIBOR plus the related margin and        
                                                (z) 10.50%. The Class B Certificates will receive  
                                                interest at a certificate interest rate equal to   
                                                the least of (x) the Weighted Average Pass-Through 
                                                Rate, (y) LIBOR plus the related margin and        
                                                (z) 10.50%. Accordingly, the Class A and Class B   
                                                Certificates will be sensitive to changes in LIBOR.
                                                No prediction can be made as to future levels of   
                                                LIBOR. See 'Description of the Certificates --     

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                                                  Distributions of Interest' and ' -- Calculation of  
                                                  LIBOR' in this prospectus supplement.               

THE CLASS A CERTIFICATES MAY RECEIVE INTEREST AT  The Class A Certificates will receive interest at a 
A CERTIFICATE INTEREST RATE LOWER THAN THE        certificate interest rate equal to the least of     
LESSER OF LIBOR PLUS THE RELATED MARGIN AND       (x) the Adjusted Weighted Average Pass-Through      
10.50%                                            Rate, (y) LIBOR plus the related margin and         
                                                  (z) 10.50%. For any class of these certificates,    
                                                  the prepayment of mortgage loans with relatively    
                                                  higher pass-through rates may cause the Adjusted    
                                                  Weighted Average Pass-Through Rate to be lower than 
                                                  LIBOR plus the related margin, in which case the    
                                                  certificate interest rate for these certificates    
                                                  will be limited to the lesser of (i) the Adjusted   
                                                  Weighted Average Pass-Through Rate and              
                                                  (ii) 10.50%.                                        

                                                  If on any distribution date the certificate         
                                                  interest rate for any class of the Class A          
                                                  Certificates is limited to the Adjusted Weighted    
                                                  Average Pass-Through Rate, a carryover shortfall    
                                                  amount, equal to the excess, if any, of (i) the     
                                                  amount of interest that would have accrued on such  
                                                  class at a certificate interest rate equal to the   
                                                  lesser of (a) LIBOR plus the related margin and     
                                                  (b) 10.50%, over (ii) the actual amount of interest 
                                                  accrued on such class for such distribution date,   
                                                  will be payable to such certificates, to the extent 
                                                  of available funds on that distribution date or     
                                                  future distribution dates. However, any such        
                                                  carryover shortfall amount will be paid on any      
                                                  distribution date only to the extent that there are 
                                                  amounts on deposit to pay such shortfalls, funded,  
                                                  first from payments made under the yield            
                                                  maintenance agreement and, second, from interest    
                                                  accrued on and otherwise distributable to the       
                                                  Class X Certificates. Furthermore, on any           
                                                  distribution date the amounts available to pay such 
                                                  carryover shortfall amount from interest accrued on 
                                                  and otherwise distributable to the Class X          
                                                  Certificates will be paid to the Class A            
                                                  Certificates, pro rata based on unpaid carryover    
                                                  shortfall amounts. Accordingly, these carryover     
                                                  shortfall amounts may remain unpaid on the date of  
                                                  any optional termination of the Trust or the final  
                                                  distribution date. Except to the extent that any    
                                                  carryover shortfall amounts are paid to the         
                                                  Class A Certificates pursuant to the yield          
                                                  maintenance agreement or from amounts otherwise     
                                                  distributable to the Class X Certificates, the      
                                                  holders of the Class A Certificates will be subject 
                                                  to the risk that interest distributable to those    
                                                  classes will equal the lesser of (i) the Adjusted   
                                                  Weighted Average Pass-Through Rate and              
                                                  (ii) 10.50%. See 'Description of the Certificates --
                                                  Distributions of Interest' in this prospectus       
                                                  supplement.                                         

THE CLASS B CERTIFICATES MAY RECEIVE INTEREST AT  The Class B Certificates will receive interest at a 
A CERTIFICATE INTEREST RATE LOWER THAN THE        certificate interest rate equal to the least of     
LESSER OF LIBOR PLUS THE RELATED MARGIN AND       (x) the Weighted Average Pass-Through Rate,         
10.50%                                            (y) LIBOR plus the related margin and (z) 10.50%.   
                                                  For any class of these certificates, the prepayment 
                                                  of mortgage loans with relatively higher            
                                                  pass-through rates may cause the Weighted Average   
                                                  Pass-Through Rate to be lower than LIBOR plus the   
                                                  related margin, in which case the                   

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                                                 certificate interest rate for these certificates   
                                                 will be limited to the lesser of (i) the Weighted  
                                                 Average Pass-Through Rate and (ii) 10.50%. See     
                                                 'Description of the Certificates -- Distributions  
                                                 of Interest' in this prospectus supplement.        

                                                 If on any distribution date the certificate        
                                                 interest rate for any class of the Class B         
                                                 Certificates is limited to the Weighted Average    
                                                 Pass-Through Rate, a carryover shortfall amount,   
                                                 equal to the excess, if any, of (i) the amount of  
                                                 interest that would have accrued on such class at a
                                                 certificate interest rate equal to the lesser of   
                                                 (a) LIBOR plus the related margin and (b) 10.50%,  
                                                 over (ii) the actual amount of interest accrued on 
                                                 such class for such distribution date, will be     
                                                 payable to such certificates, to the extent of     
                                                 available funds on that distribution date or future
                                                 distribution dates. However, any such carryover    
                                                 shortfall amount will be paid on any distribution  
                                                 date only to the extent that there are amounts on  
                                                 deposit to pay such shortfalls, funded from        
                                                 interest accrued on and otherwise distributable to 
                                                 the Class X Certificates to the extent remaining   
                                                 after such interest has been applied to pay        
                                                 carryover shortfall amounts to the Class A         
                                                 Certificates. Furthermore, on any distribution date
                                                 the amounts available to pay such carryover        
                                                 shortfall amount will be paid to the Class B       
                                                 Certificates in order of seniority. Accordingly,   
                                                 these carryover shortfall amounts may remain unpaid
                                                 on the date of any optional termination of the     
                                                 Trust or the final distribution date. Except to the
                                                 extent that any carryover shortfall amounts are    
                                                 paid to the Class B Certificates from amounts      
                                                 otherwise distributable to the Class X             
                                                 Certificates, the holders of these Class B         
                                                 Certificates will be subject to the risk that      
                                                 interest distributable to those classes will equal 
                                                 the lesser of (i) the Weighted Average Pass-Through
                                                 Rate and (ii) 10.50%. See 'Description of the      
                                                 Certificates -- Distributions of Interest' in this 
                                                 prospectus supplement.                             

PAYMENTS MADE PURSUANT TO THE YIELD MAINTENANCE  For any distribution date (other than the first    
AGREEMENT MAY NOT BE SUFFICIENT TO COVER         distribution date and any distribution date after  
CARRYOVER SHORTFALL AMOUNTS ON THE CLASS A       the distribution date in February 2014) on which   
CERTIFICATES                                     the certificate interest rate on any of the        
                                                 Class A Certificates is limited to the Adjusted    
                                                 Weighted Average Pass-Through Rate, such class of  
                                                 Certificates may be entitled to receive, as        
                                                 interest, payments pursuant to the yield           
                                                 maintenance agreement. Payments under the yield    
                                                 maintenance agreement on any distribution date will
                                                 generally equal the product of (i) a fraction, the 
                                                 numerator of which is the actual number of days in 
                                                 the certificate accrual period and the denominator 
                                                 of which is 360, (ii) the excess, if any, of (x)   
                                                 LIBOR, subject to a maximum of 10.17%, over (y) the
                                                 related cap strike rate specified on Schedule 1 to 
                                                 this prospectus supplement and (iii) the lesser of 
                                                 (x) the aggregate principal balance of the Class A 
                                                 Certificates immediately prior to such distribution
                                                 date and (y) the related yield maintenance notional
                                                 balance specified on Schedule 1 to                 

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                                               this prospectus supplement. The yield maintenance  
                                               notional balance will be calculated based upon an  
                                               assumed constant prepayment rate on the mortgage   
                                               loans equal to 25% CPR per annum. If the actual    
                                               prepayment rate on the mortgage loans is slower    
                                               than the prepayment rate assumed for purposes of   
                                               determining the yield notional balance, or if LIBOR
                                               exceeds certain levels payments pursuant to the    
                                               yield maintenance agreement may not be sufficient  
                                               to cover carryover shortfall amounts allocated to  
                                               the applicable class of certificates that would    
                                               otherwise be covered by amounts payable pursuant to
                                               the yield maintenance agreement.                   

CERTIFICATES BOUGHT AT PREMIUMS AND DISCOUNTS  If you purchase a certificate at a discount from   
MAY RECEIVE A LOWER YIELD THAN EXPECTED        its original principal balance and the rate of     
                                               principal payments is slower than you expect, your 
                                               yield may be lower than you anticipate. If you     
                                               purchase a certificate at a premium over its       
                                               original principal balance and the rate of         
                                               principal payments is faster than you expect, your 
                                               yield may be lower than you anticipate.            

LOSSES ON THE MORTGAGE LOANS WILL REDUCE THE   The yield to maturity of the Class B-1, Class B-2, 
YIELD ON THE CERTIFICATES                      Class B-3, Class B-4, Class B-5, Class B-6,        
                                               Class B-7, Class B-8 and Class B-9 Certificates    
                                               will be sensitive to losses on the mortgage loans  
                                               that occur after the aggregate principal balance of
                                               the Class B-10, Class B-11, Class B-12 and         
                                               Class B-13 Certificates has been reduced to zero.  
                                               Losses on the mortgage loans that occur after that 
                                               time will be allocated exclusively to the          
                                               Class B-1, Class B-2, Class B-3, Class B-4,        
                                               Class B-5, Class B-6, Class B-7, Class B-8 and     
                                               Class B-9 Certificates in reverse numerical order  
                                               until the aggregate principal balance of those     
                                               certificates has been reduced to zero.             

                                               In addition, if the aggregate principal balance of 
                                               all the subordinate certificates has been reduced  
                                               to zero, all further losses on the mortgage loans  
                                               will be allocated to the Class A Certificates and  
                                               the Class X principal-only component, pro rata,    
                                               until their respective class principal or          
                                               component, as applicable, balances have been       
                                               reduced to zero; provided, however, that any loss  
                                               that would otherwise be allocated to the           
                                               Class A-1A Certificates will be allocated          
                                               (i) first, to the Class A-1C1, Class A-1C2,        
                                               Class A-1C3 and Class A-1C4 Certificates, pro rata,
                                               until their respective class principal balances    
                                               have each been reduced to zero and (ii) second, to 
                                               the Class A-1B1, Class A-1B2 and Class A-1B3       
                                               Certificates, pro rata, until their respective     
                                               class principal balances have each been reduced to 
                                               zero; and provided, further, that any loss that    
                                               would otherwise be allocated to the Class A-1B1,   
                                               Class A-1B2 or Class A-1B3 Certificates will be    
                                               allocated to the Class A-1C1, Class A-1C2,         
                                               Class A-1C3 and Class A-1C4 Certificates, pro rata,
                                               until their respective class principal balances    
                                               have each been reduced to zero.                    

                                               See 'Description of the Certificates --            
                                               Subordination and Allocation of Losses' in this    
                                               prospectus supplement.                             

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THE LACK OF SECONDARY MARKETS MAY MAKE IT         The offered certificates will not be listed on any 
DIFFICULT FOR YOU TO RESELL YOUR CERTIFICATES     securities exchange. A secondary market for the    
                                                  offered certificates may not develop. If a         
                                                  secondary market does develop, it might not        
                                                  continue or it might not be sufficiently liquid to 
                                                  allow you to resell any of your certificates. You  
                                                  should not expect to be able to obtain a published 
                                                  quotation to sell any of the offered certificates. 

THE LACK OF PHYSICAL CERTIFICATES FOR SOME        You will NOT have a physical certificate if you own
CERTIFICATES MAY CAUSE DELAYS IN PAYMENT          a Class A, Class X, Class B-1, Class B-2,          
                                                  Class B-3, Class B-4, Class B-5, Class B-6,        
                                                  Class B-7, Class B-8 or Class B-9 Certificate. As a
                                                  result, you will be able to transfer your          
                                                  certificates only through The Depository Trust     
                                                  Company, participating organizations, including    
                                                  Euroclear and Clearstream and indirect             
                                                  participants. In addition, you may experience some 
                                                  delay in receiving distributions on these          
                                                  certificates because the trustee will not send     
                                                  distributions directly to you. Instead, the trustee
                                                  will send all distributions to The Depository Trust
                                                  Company, which will then credit those distributions
                                                  to the participating organizations. Those          
                                                  organizations will in turn credit accounts you have
                                                  either directly with them or indirectly with them  
                                                  through indirect participants.                     

THE RETURN ON YOUR CERTIFICATES COULD BE REDUCED  Following the terrorist attacks in the United      
DUE TO THE SERVICEMEMBERS CIVIL RELIEF ACT OR     States on September 11, 2001, the United States has
ANY COMPARABLE STATE LEGISLATION                  increased its active military operations           
                                                  (including, most recently, significant military    
                                                  actions in Iraq) and has placed a substantial      
                                                  number of military reservists and members of the   
                                                  National Guard on active duty status. It is        
                                                  possible that the number of reservists and members 
                                                  of the National Guard placed on active duty status 
                                                  in the near future may increase. Calling           
                                                  reservists, members of the National Guard and      
                                                  civilians to active military duty may adversely    
                                                  affect the performance of your certificates. Under 
                                                  the Servicemembers Civil Relief Act (the 'RELIEF   
                                                  ACT'), formerly known as the Soldiers' and Sailors'
                                                  Civil Relief Act of 1940, persons in active        
                                                  military service are provided relief from the      
                                                  performance of some payment obligations. The relief
                                                  includes a 6.000% per annum interest rate cap on   
                                                  each mortgage loan, provided that the mortgage loan
                                                  was obtained before the commencement of active     
                                                  military service. In addition, all civil court     
                                                  actions, such as bankruptcy and foreclosure        
                                                  proceedings, are delayed.                          

                                                  State legislation may provide similar relief for   
                                                  military personnel placed on active duty status.   
                                                  For the purpose of this prospectus supplement,     
                                                  references to the Relief Act include any such      
                                                  comparable state legislation.                      

                                                  The application of the interest rate cap to any    
                                                  mortgage loan underlying the certificates would    
                                                  result in certificateholders receiving less        
                                                  interest than they would otherwise be entitled to. 
                                                  The interest shortfall on any distribution date    
                                                  arising out of each of these mortgage loans would  
                                                  be equal to one month of interest on the           

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                                                  principal balance of the mortgage loan at a rate   
                                                  equal to the difference between the interest rate  
                                                  payable by the borrower under the terms of the     
                                                  applicable mortgage note and 6.000%. The interest  
                                                  shortfall would be deducted from the interest      
                                                  payable to each class of certificates, pro rata, in
                                                  accordance with interest accrued on each class of  
                                                  certificates for the applicable distribution date. 

                                                  The effect of a delay in foreclosure proceedings   
                                                  with respect to any mortgage loan underlying the   
                                                  certificates would be to cause a loss, or increase 
                                                  the severity of any loss that would have otherwise 
                                                  occurred, upon the final liquidation of the        
                                                  mortgage loan. These losses would be applied first 
                                                  to the Class B-13, Class B-12, Class B-11,         
                                                  Class B-10, Class B-9, Class B-8, Class B-7,       
                                                  Class B-6, Class B-5, Class B-4, Class B-3,        
                                                  Class B-2 and Class B-1 Certificates, in that      
                                                  order, and then to the senior certificates.        

                                                  Neither Washington Mutual Mortgage Securities Corp.
                                                  nor Washington Mutual Bank is able to determine how
                                                  many of the mortgage loans underlying the          
                                                  certificates may be affected by application of the 
                                                  Relief Act in the future.                          

THE GEOGRAPHIC CONCENTRATION OF THE MORTGAGED     The geographic concentration of mortgaged          
PROPERTIES RELATING TO THE MORTGAGE LOANS         properties can expose the related mortgage loans to
INCREASES YOUR EXPOSURE TO ADVERSE CONDITIONS IN  a higher incidence of losses due to a greater      
CALIFORNIA                                        susceptibility to hazards not covered by standard  
                                                  hazard insurance, such as hurricanes, floods,      
                                                  mudslides and earthquakes, than properties located 
                                                  in other parts of the country. Also, the geographic
                                                  concentration of mortgaged properties can expose   
                                                  the related mortgage loans to a higher incidence of
                                                  losses due to economic conditions in states that   
                                                  have higher concentrations of businesses in        
                                                  particular economic segments than the nation as a  
                                                  whole. Approximately 67.2% of the mortgage loans   
                                                  (by aggregate principal balance as of August 1,    
                                                  2005) are secured by mortgaged properties located  
                                                  in California. The high concentration of mortgage  
                                                  loans in California may adversely affect losses and
                                                  prepayments on the mortgage loans which, in turn,  
                                                  would adversely affect the certificates. See       
                                                  Appendix B to this prospectus supplement for a     
                                                  table showing the geographic distribution of the   
                                                  mortgage loans by state.                           

A LOSS OR DELINQUENCY ON A MORTGAGE LOAN MAY      As of August 1, 2005, the average principal balance
HAVE A DISPROPORTIONATE IMPACT ON THE             of the mortgage loans was approximately $630,504,  
PERFORMANCE OF THE MORTGAGE POOL BECAUSE THE      and approximately 20.6% of the mortgage loans (by  
MORTGAGE LOANS HAVE HIGH PRINCIPAL BALANCES       aggregate principal balance as of August 1, 2005)  
                                                  had original principal balances in excess of       
                                                  $1,000,000. You should consider the risk that the  
                                                  loss and delinquency experience on the higher      
                                                  balance mortgage loans may have a disproportionate 
                                                  effect on the mortgage loans as a whole. A loss of 
                                                  the entire principal balance of one of these       
                                                  mortgage loans may result in a substantial realized
                                                  loss, which may be allocated to the offered        
                                                  certificates.                                      

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CERTAIN MATTERS RELATING TO CONSERVATORSHIP OR  The servicer is chartered as a federal savings     
RECEIVERSHIP OF THE SERVICER                    association and is regulated and supervised by the 
                                                Office of Thrift Supervision (the 'OTS'), which is 
                                                authorized to appoint the Federal Deposit Insurance
                                                Corporation (the 'FDIC') as conservator or receiver
                                                for the servicer if certain events occur relating  
                                                to the servicer's financial condition or the       
                                                propriety of its actions. In addition, the FDIC    
                                                could appoint itself as conservator or receiver for
                                                the servicer.                                      

                                                If the FDIC were appointed as receiver or          
                                                conservator for the servicer, then regardless of   
                                                the terms of the pooling agreement, the FDIC       
                                                (i) could prevent the appointment of a successor   
                                                servicer, (ii) could authorize the servicer to stop
                                                servicing the mortgage loans, or (iii) could       
                                                increase the amount or the priority of the         
                                                servicing fee due to the servicer or otherwise     
                                                alter the terms under which the servicer services  
                                                the mortgage loans. If any of these events were to 
                                                occur, payments on the certificates could be       
                                                delayed or reduced.                                

                                                The administrative expenses of a conservator or    
                                                receiver for the servicer that the conservator or  
                                                receiver determines to be related to the mortgage  
                                                loans or the pooling agreement could be paid from  
                                                collections on the mortgage loans before the Trust 
                                                or the holders of the certificates receive any     
                                                payments, thereby resulting in delays or reductions
                                                in payments on the certificates.                   

                                                The Trust may not have a perfected interest in     
                                                collections on the mortgage loans held by the      
                                                servicer, and thus if an insolvency proceeding were
                                                commenced by or against the servicer, payments on  
                                                the certificates could be delayed or reduced.      

CERTAIN REGULATORY MATTERS REGARDING            The operations and financial condition of the      
THE SERVICER                                    servicer are subject to extensive regulation and   
                                                supervision under federal and state law. The       
                                                appropriate banking regulatory authorities,        
                                                including the OTS and the FDIC, have broad         
                                                enforcement powers over the servicer.              

                                                If federal bank regulatory authorities supervising 
                                                any bank were to find that any obligation of such  
                                                bank or an affiliate under a securitization or     
                                                other agreement, or any activity of such bank or   
                                                affiliate, constituted an unsafe or unsound        
                                                practice or violated any law, rule, regulation or  
                                                written condition or agreement applicable to the   
                                                related bank, such federal bank regulatory         
                                                authorities have the power to order such bank or   
                                                affiliate, among other things, to rescind such     
                                                agreement or contract, refuse to perform that      
                                                obligation, terminate the activity, amend the terms
                                                of such obligation or take such other action as    
                                                such regulatory authorities determine to be        
                                                appropriate. If such an event occurs with respect  
                                                to the servicer or its affiliates, the servicer may
                                                not be liable to the holders of the certificates   
                                                for contractual damages for complying with such an 
                                                order and the holders of the certificates may have 
                                                no recourse against the relevant regulatory        
                                                authority.                                         

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                                                 Recently, after the Office of the Comptroller of   
                                                 the Currency (the 'OCC') found that a national bank
                                                 was, contrary to safe and sound banking practices, 
                                                 receiving inadequate servicing compensation under  
                                                 its securitization agreements, that bank agreed to 
                                                 a consent order with the OCC. Such consent order   
                                                 requires that bank, among other things, to resign  
                                                 as servicer and to cease performing its duties as  
                                                 servicer within approximately 120 days, to         
                                                 immediately withhold and segregate funds from      
                                                 collections for payment of its servicing fee       
                                                 (notwithstanding the priority of payments in the   
                                                 securitization agreements and the perfected        
                                                 security interest of the relevant trust in those   
                                                 funds) and to increase its servicing fee percentage
                                                 above that which was originally agreed upon in its 
                                                 securitization agreements.                         

                                                 While the servicer has no reason to believe that   
                                                 any appropriate banking regulatory authority would 
                                                 consider provisions relating to the servicer acting
                                                 as servicer or the payment or amount of a servicing
                                                 fee to the servicer, or any other obligation of the
                                                 servicer under its securitization agreements to be 
                                                 unsafe or unsound or violative of any law, rule or 
                                                 regulation applicable to it, there can be no       
                                                 assurance that any such regulatory authority would 
                                                 not conclude otherwise in the future. If such a    
                                                 regulatory authority did reach such a conclusion   
                                                 and ordered the servicer to rescind or amend its   
                                                 securitization agreements, payments to the holders 
                                                 of the certificates could be delayed or reduced.   

PAYMENTS UNDER THE YIELD MAINTENANCE AGREEMENT   To the extent that distributions on the Class A    
TO THE CLASS A CERTIFICATES ARE SUBJECT TO THE   Certificates depend on payments to be received by  
RISK OF NON-PAYMENT BY THE COUNTERPARTY TO THAT  the trustee under the yield maintenance agreement, 
AGREEMENT                                        the ability of the trustee to make those           
                                                 distributions will be subject to the credit risk of
                                                 Bear Stearns Financial Products Inc., the          
                                                 counterparty to the agreement. Although there is a 
                                                 mechanism in place to facilitate the replacement of
                                                 the agreement upon the default or credit impairment
                                                 of the counterparty, there can be no assurance that
                                                 any such mechanism will result in the ability to   
                                                 obtain a suitable replacement agreement.           

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THE TRUST 

   The issuer of the certificates, the WaMu Mortgage Pass-Through Certificates
Series 2005-AR11 Trust (the 'TRUST'), will be a statutory trust formed under the
laws of the State of Delaware pursuant to a trust agreement between Washington  
Mutual Mortgage Securities Corp., as depositor, and Deutsche Bank Trust Company 
Delaware, as Delaware trustee. Pursuant to the pooling agreement among          
Washington Mutual Mortgage Securities Corp., as depositor, Washington Mutual    
Bank, as servicer, Deutsche Bank National Trust Company, as trustee, and        
Deutsche Bank Trust Company Delaware, as Delaware trustee, which will amend and 
restate the trust agreement, a pool of mortgage loans, as described in this     
prospectus supplement, will be sold to the Trust on August 25, 2005 (the        
'CLOSING DATE'). As used in this prospectus supplement, the 'trustee' will refer
to Deutsche Bank National Trust Company acting in its capacity as trustee under 
the pooling agreement.                                                          

 The mortgage notes will not be endorsed to the Trust and no assignment of
the mortgages to the Trust will be prepared. Washington Mutual Bank fsb, a      
wholly-owned subsidiary of Washington Mutual Bank, the servicer of the mortgage 
loans, will retain possession of and will review the mortgage notes and         
mortgages as custodian for the Trust and financing statements will be filed     
evidencing the Trust's interest in the mortgage loans. The mortgage pool will be
the primary asset of the Trust. The Trust will own the right to receive all     
payments of principal and interest on the mortgage loans due after August 1,    
2005 (the 'CUT-OFF DATE'). In exchange for the mortgage loans and other         
property, the trustee will authenticate and deliver the certificates to         
Washington Mutual Mortgage Securities Corp. A schedule to the pooling agreement 
will include information about each mortgage loan, including:                   

the outstanding principal balance as of the close of  
business on the Cut-Off Date;                         

the term of the mortgage loan; and                    

   the mortgage interest rate as of the close of business on
  the Cut-Off Date and information about how that mortgage
interest rate adjusts.                                

The Trust will also contain other property, including:                          

     insurance policies related to individual mortgage loans, if
applicable;                                           

 any property that Washington Mutual Mortgage Securities
Corp. acquires after the Cut-Off Date as a result of  
   foreclosure or threatened foreclosure of a mortgage loan;

the rights of the Trust under the yield maintenance   
agreement; and                                        

  amounts held in the Certificate Account (as described on
page 28 of the accompanying prospectus).              

The pooling agreement permits the servicer, to place funds that would   
otherwise be held in the Certificate Account into an Investment Account and     
invest them in Eligible Investments for its own benefit, before those funds are 
remitted to the trustee to be distributed to certificateholders.                

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DESCRIPTION OF THE MORTGAGE POOL* 

The mortgage pool will consist of 5,077 mortgage loans that will have an
aggregate principal balance as of the Cut-Off Date, after deducting payments due
on or before that date, of approximately $3,201,069,294.                        

    The mortgage loans are secured by first mortgages or first deeds of trust or
other similar security instruments creating first liens on fee simple or        
leasehold interests in one- to four-family residential properties or, shares of 
stock relating to cooperative apartments. These mortgaged properties, which may 
include detached homes, duplexes, townhouses, individual condominium units,     
individual units in planned unit developments and other attached dwelling units 
that are part of buildings consisting of more than four units (so long as the   
mortgaged property (other than cooperative apartments) consists of no more than 
four units), have the additional characteristics described below, in Appendix B 
to this prospectus supplement and in the prospectus.                            

    As of the Cut-Off Date, approximately 0.3% of the borrowers are obligated on
more than one mortgage loan underlying the certificates. As of the Cut-Off Date,
the maximum number of mortgage loans related to a single borrower is two, and   
the maximum aggregate principal balance of mortgage loans related to a single   
borrower obligated on more than one mortgage loan represents approximately 0.1% 
of the mortgage loans by principal balance.                                     

   For all mortgage loans, the Minimum Monthly Payment (as defined below) will
be due on the first day of each month (the 'DUE DATE'). Each mortgage loan will 
have a first Due Date during the period from September 2004 through August 2005,
inclusive, and will have an original term to maturity of not more than 40 years.

Each mortgage loan will be a conventional mortgage loan evidenced by a  
mortgage note. After an initial fixed-rate period for some of the mortgage loans
of one, two, three or twelve months, the mortgage interest rate on each mortgage
loan will be adjusted monthly to equal the sum of the Index (as defined below)  
and the per annum rate specified in the applicable mortgage note (the 'MARGIN'),
rounded to the nearest 0.001%. The Margin for each mortgage loan may change if  
the initial Index is replaced. See 'The Index' in this prospectus supplement. In
addition, adjustments to the mortgage interest rate for each mortgage loan are  
subject to a lifetime maximum interest rate (a 'RATE CEILING'). The minimum     
interest rate for each mortgage loan is its related Margin.                     

   Each mortgage loan was originated with an initial fixed-rate period of one,
two, three or twelve months. As of the Cut-Off Date, none of the mortgage loans 
were still in their one, two, three or twelve month fixed-rate period.          

  Each mortgage loan allows the related mortgagor to choose, each month, one
of several payment options, which may include an amount less than, equal to or  
greater than a fully-amortizing monthly payment. The 'MINIMUM MONTHLY PAYMENT'  
is the minimum monthly payment required to be paid by                           

---------                                                                       
* The description of the mortgage pool and the mortgaged properties in this     
section and in Appendix B is based on the mortgage loans as of the close of 
  business on the Cut-Off Date, after deducting the scheduled principal payments
due on or before that date, whether or not actually received. All references
in this prospectus supplement to 'principal balance' refer to the principal 
balance as of the Cut-Off Date, unless otherwise specifically stated or     
required by the context. Due to rounding, percentages may not sum to 100%.  
References to percentages of mortgage loans refer in each case to the       
 percentage of the aggregate principal balance of the mortgage loans, based on
the outstanding principal balances of the mortgage loans after giving effect
  to scheduled monthly payments due on or before the Cut-Off Date. References to
  weighted averages refer in each case to weighted averages by principal balance
as of the Cut-Off Date of the mortgage loans determined in the same way as  
described in the previous sentence. Before the issuance of the certificates,
mortgage loans may be removed from the mortgage pool as a result of Payoffs,
delinquencies or otherwise. If that happens, other mortgage loans may be    
included in the mortgage pool. Washington Mutual Mortgage Securities Corp.  
believes that the information in this prospectus supplement for the mortgage
 pool is representative of the characteristics of the mortgage pool as it will
actually be constituted when the certificates are issued, although the range
 of mortgage interest rates and other characteristics of the mortgage loans in
the mortgage pool may vary. See ' -- Additional Information' in this        
prospectus supplement.                                                      

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the mortgagor pursuant to the terms of the mortgage note. In general, when the  
Minimum Monthly Payment is less than the amount of interest due that month      
(which is calculated each month as the sum of the Index and the Margin), the    
mortgagor will have the option to pay the actual amount of interest due that    
month. Likewise, whenever the Minimum Monthly Payment is less than a            
fully-amortizing monthly payment, the mortgagor will be given the option to pay 
that fully-amortizing amount. Finally, the mortgagor will have the option of    
paying a monthly payment that would amortize the mortgage loan in 15 years,     
rather than the 30-year or 40-year term of the mortgage loan.                   

The initial Minimum Monthly Payment for each mortgage loan is the amount
which will fully amortize the mortgage loan at its initial fixed interest rate  
(which will generally be lower than the sum of the Index and Margin) in equal   
monthly installments over its remaining term to maturity. The Minimum Monthly   
Payment for each mortgage loan will adjust annually, and on any Due Date on     
which the principal balance of the mortgage loan would otherwise exceed 110% (in
the case of approximately 4.2% of the mortgage loans, as of the Cut-Off Date) or
125% (in the case of approximately 95.8% of the mortgage loans, as of the       
Cut-Off Date) of its original principal balance, to an amount which will fully  
amortize the mortgage loan at the then current mortgage interest rate in equal  
monthly installments over its remaining term to maturity. The Minimum Monthly   
Payment may not, however, increase or decrease on any adjustment date by an     
amount greater than 7.5% of the Minimum Monthly Payment in effect immediately   
before that adjustment date (the 'PAYMENT CAP'), provided that this 7.5%        
limitation does not apply to the adjustment made on the fifth anniversary of the
first Due Date and each fifth anniversary thereafter or if the principal balance
of the mortgage loan would otherwise exceed 110% or 125%, as applicable, of its 
original principal balance. The final payment on each mortgage loan also is not 
subject to any limit on the change in the Minimum Monthly Payment. Depending on 
the amount and timing of increases to the principal balance of a mortgage loan  
due to negative amortization, the final payment on that mortgage loan may be    
substantially larger than the immediately preceding Minimum Monthly Payment.    

  Since the mortgage interest rate on each mortgage loan adjusts monthly and
the Minimum Monthly Payment adjusts annually, subject to the limitations        
described above, and since the Minimum Monthly Payment may not be increased on  
most adjustment dates by an amount greater than 7.5%, increases in the Index    
will cause a larger portion of the monthly payment to be allocated to interest  
and a smaller portion to principal. In some cases, the interest due on the      
mortgage loan may exceed the monthly payment. Any such excess will be added to  
the outstanding principal balance of the mortgage loan in the form of 'negative 
amortization.' Decreases in the Index, on the other hand, will cause a larger   
portion of the monthly payment to be allocated to principal and a smaller       
portion to interest.                                                            

 Although none of the mortgage loans were in their fixed-rate period as of
the Cut-Off Date, the Minimum Monthly Payment for the entire first year of the  
mortgage loan following origination reflects the fixed rate in effect during    
that initial fixed-rate period, which will generally be lower than the fully    
indexed rate in effect at any time during the first year. Therefore, even if the
Index does not increase, the Minimum Monthly Payment during the first five years
of the mortgage loan may not be enough to pay the amount of interest due on the 
mortgage loan at the fully indexed rate, which is calculated based on the sum of
the Index and the Margin. If the mortgagor chooses to pay the Minimum Monthly   
Payment rather than the other higher payment options, this will lead to an      
increase in the outstanding principal balance of the mortgage loan in the form  
of negative amortization. Even after the first year, when the Minimum Monthly   
Payment may increase by 7.5%, this adjustment may not be enough to raise the    
Minimum Monthly Payment to the amount necessary to pay the interest due on the  
mortgage loan based on the sum of the Index and the Margin in effect during the 
following year. If the new Minimum Monthly Payment is still less than the fully 
indexed rate during the following year, there will continue to be negative      
amortization if the mortgagor chooses to pay only the Minimum Monthly Payment.  
Therefore the effect of the initial fixed rate at the beginning of the life of  
the mortgage loan may continue to cause the Minimum Monthly Payment to be less  
than the monthly interest due on the mortgage loan until the fifth anniversary  
of the first Due Date when the Minimum Monthly Payment will be reset to a       
fully-amortizing payment.                                                       

    In addition, for any month, if the servicer receives a payment on a mortgage
loan that is less than the Minimum Monthly Payment or if no payment is received 
at all, the servicer will advance its own funds to cover the difference between 
the Minimum Monthly Payment scheduled to be received and the                    

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amount actually received with respect to that mortgage loan. However, the       
servicer will not be required to make such advances if it determines that those 
advances will not be recoverable from future payments or collections on that    
mortgage loan.                                                                  

All of the mortgage loans are assumable to the extent provided in the   
related mortgage note. The mortgage note for each mortgage loan provides that if
the mortgage loan is assumed, the Rate Ceiling following the assumption will be 
the greater of (i) the original Rate Ceiling for the mortgage loan or (ii) the  
interest rate in effect for the mortgage loan at the time of assumption plus    
five percentage points.                                                         

The mortgage loans sold to the WaMu Mortgage Pass-Through Certificates  
Series 2005-AR11 Trust were purchased by Washington Mutual Mortgage Securities  
Corp. directly from Washington Mutual Bank, an affiliate of Washington Mutual   
Mortgage Securities Corp.                                                       

   None of the mortgage loans will be buydown loans. Some of the risks of loss
on some mortgage loans will be covered up to specified limits by primary        
insurance policies. As of the Cut-Off Date, approximately 1.1% of the mortgage  
loans were covered by a primary insurance policy. All of the mortgage loans with
original loan-to-value ratios as of the Cut-Off Date in excess of 80% were      
covered by a primary insurance policy.                                          

    As of the Cut-Off Date, approximately 73.5% (by aggregate principal balance)
of the mortgage loans impose penalties for early prepayments in full (but do not
impose penalties for partial prepayments) received on or before the first       
anniversary of the origination of the mortgage loan. As of the Cut-Off Date,    
approximately 8.1% (by aggregate principal balance) of the mortgage loans impose
penalties for early prepayments in full (but do not impose penalties for partial
prepayments) received on or before the third anniversary of the origination of  
the mortgage loan. As of the Cut-Off Date, approximately 1.3% (by aggregate     
principal balance) of the mortgage loans impose penalties for early prepayments 
in full, and for partial prepayments in the event that aggregate partial        
prepayments made during a 12-month period exceed 20% of the original principal  
balance. Those prepayment penalties are in effect for 30 months after the       
origination of those mortgage loans. The amount of the applicable prepayment    
penalty, to the extent permitted by applicable law, is as provided in the       
related mortgage note. All prepayment penalty payments remitted to the Trust    
with respect to voluntary full prepayments will be distributed to the holders of
the Class PPP Certificates. The holders of the Class PPP Certificates will not  
receive any prepayment penalty payment remitted to the Trust with respect to    
voluntary partial prepayments; each such payment will be retained by the        
servicer as additional servicing compensation. No prepayment penalty payments   
will be available for distribution to holders of the other classes of           
certificates. Notwithstanding the foregoing, no penalties are imposed (i) in    
some cases where the mortgagor sells the mortgaged property and obtains a new   
mortgage loan originated and serviced by Washington Mutual Bank to purchase     
another property, provided that the prepayment is made no earlier than one year 
after origination, (ii) in some cases where the mortgagor refinances the        
mortgage loan with a new mortgage loan originated and serviced by Washington    
Mutual Bank, provided that 90 days or less remain in the prepayment penalty     
term, or (iii) for prepayments of accrued but unpaid interest that has been     
added to principal as a result of negative amortization.                        

SEE APPENDIX B FOR A DETAILED DESCRIPTION OF THE MORTGAGE LOANS.        

THE INDEX                                                                       

   The index for the mortgage loans (the 'INDEX') is a per annum rate equal to
the twelve-month moving average monthly yield on United States Treasury         
Securities adjusted to a constant maturity of one year ('ONE-YEAR MTA'), as     
published by the Board of Governors of the Federal Reserve System in the Federal
Reserve Statistical Release 'Selected Interest Rates (H.15)', determined by     
averaging the monthly yields for the most recently available twelve months. The 
One-Year MTA figure used for each interest rate adjustment date will be the most
recent One-Year MTA figure available as of fifteen days before that date.       

    If One-Year MTA is no longer available, the servicer will choose a new Index
that is based on comparable information. When the servicer chooses a new Index, 
it will increase or decrease the Margin on each mortgage loan by the difference 
between the average of One-Year MTA for the final three years it was in effect  
and the average of the replacement index for the most recent three years. The   
Margin will                                                                     

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be increased by that difference if the average of One-Year MTA is greater than  
the average of the replacement index, and the Margin will be decreased by that  
difference if the average of the replacement index is greater than the average  
of One-Year MTA. The new Margin will be rounded up as provided in the related   
mortgage note.                                                                  

Listed below are some historical values of One-Year MTA since 2000. The 
values of One-Year MTA shown are intended only to provide an historical summary 
of the movements in the One-Year MTA and may not be indicative of future rates. 
No assurances can be given as to the value of One-Year MTA on any interest rate 
adjustment date or during the life of any mortgage loan.                        

                                                        [Enlarge/Download Table]

                                                                YEAR                        
                                         ---------------------------------------------------
                 MONTH                    2005     2004     2003     2002     2001     2000 
                 -----                    ----     ----     ----     ----     ----     ---- 
                                                                                            
January................................. 2.022%   1.234%   1.935%   3.260%   5.999%   5.212%
February................................ 2.171%   1.229%   1.858%   3.056%   5.871%   5.338%
March................................... 2.347%   1.225%   1.747%   2.912%   5.711%   5.458%
April................................... 2.504%   1.238%   1.646%   2.787%   5.530%   5.580%
May..................................... 2.633%   1.288%   1.548%   2.668%   5.318%   5.703%
June.................................... 2.737%   1.381%   1.449%   2.553%   5.102%   5.793%
July.................................... 2.865%   1.463%   1.379%   2.414%   4.897%   5.880%
August..................................          1.522%   1.342%   2.272%   4.671%   5.962%
September...............................          1.595%   1.302%   2.180%   4.395%   6.035%
October.................................          1.677%   1.268%   2.123%   4.088%   6.083%
November................................          1.773%   1.256%   2.066%   3.763%   6.128%
December................................          1.887%   1.244%   2.002%   3.481%   6.108%

ADDITIONAL INFORMATION                                                          

Appendix B contains important information about the mortgage loans      
including:                                                                      

     the mortgage interest rates, the Pass-Through Rates and the
original principal balances of the mortgage loans;    

      the Margins, the interest rate floors and the Rate Ceilings;

     the years in which initial monthly payments on the mortgage
loans are due;                                        

  the first interest rate adjustment dates on the mortgage
loans;                                                

  the loan-to-value ratios of the mortgage loans as of the
Cut-Off Date;                                         

the types of mortgaged properties;                    

the geographic distribution by state of the mortgaged 
properties;                                           

the scheduled maturity years of the mortgage loans;   

the original terms to maturity of the mortgage loans; 

the number of mortgage loans originated under full    
documentation or reduced documentation programs;      

the stated owner occupancy status of the mortgaged    
properties when the mortgage loans were originated;   

the mortgagor's purpose of financing; and             

the credit score ranges.                              

  The credit score tables appearing in Appendix B show the credit scores, if
any, that the originators or underwriters of the mortgage loans collected for   
the mortgagors. Third-party credit reporting organizations provide credit scores
as an aid to lenders in evaluating the creditworthiness of borrowers. Although  
different credit reporting organizations use different methodologies, higher    
credit scores generally indicate greater creditworthiness. Credit scores do not 
necessarily correspond to the probability of default over the life of the       
related mortgage loan because they reflect past credit history, rather than an  
assessment of future payment performance. In addition, the credit scores shown  
were collected from a variety of sources                                        

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over a period of weeks, months or longer, and the credit scores do not          
necessarily reflect the credit scores that would be reported as of the date of  
this prospectus supplement. Credit scores also only indicate general consumer   
creditworthiness, and credit scores are not intended to specifically apply to   
mortgage debt. Therefore, credit scores should not be considered as an accurate 
predictor of the likelihood of repayment of the related mortgage loans.         

 The pooling agreement will be available to purchasers of the certificates
through a Current Report on Form 8-K that will be filed with the Securities and 
Exchange Commission within fifteen days after the initial issuance of the       
certificates. If mortgage loans are removed from or added to the mortgage pool  
as described in the footnote on page S-30, that removal or addition will be     
noted in the Current Report on Form 8-K.                                        

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DESCRIPTION OF THE CERTIFICATES 

GENERAL                                                                         

The certificates will be issued pursuant to the pooling agreement to be 
dated as of the Cut-Off Date among Washington Mutual Mortgage Securities Corp., 
as depositor, Washington Mutual Bank, as servicer, Deutsche Bank National Trust 
Company, as trustee, and Deutsche Bank Trust Company Delaware, as Delaware      
trustee. A form of the pooling agreement is filed as an exhibit to the          
registration statement of which this prospectus supplement is a part. The       
prospectus contains important additional information regarding the terms and    
conditions of the pooling agreement and the certificates. The offered           
certificates will not be issued unless they receive the ratings from Standard & 
Poor's Ratings Services, a division of The McGraw-Hill Companies, Inc. ('S&P'), 
and Moody's Investors Service, Inc. ('MOODY'S') indicated under 'Certificate    
Ratings' in this prospectus supplement. As of the Closing Date, the offered     
certificates, other than the Class B-4, Class B-5, Class B-6, Class B-7, Class  
B-8 and Class B-9 Certificates, will qualify as 'mortgage related securities'   
within the meaning of the Secondary Mortgage Market Enhancement Act of 1984.    

   The pooling agreement obligates the servicer to make advances when payments
on the mortgage loans are delinquent and other conditions are met, as described 
in this prospectus supplement under ' -- Advances.'                             

  The WaMu Mortgage Pass-Through Certificates, Series 2005-AR11 will consist
of the following classes:                                                       

                                                                [Download Table]
                                                                       
Class A-1A                       Class X                     Class B-8 
Class A-1B1                      Class B-1                   Class B-9 
Class A-1B2                      Class B-2                   Class B-10
Class A-1B3                      Class B-3                   Class B-11
Class A-1C1                      Class B-4                   Class B-12
Class A-1C2                      Class B-5                   Class B-13
Class A-1C3                      Class B-6                   Class R   
Class A-1C4                      Class B-7                   Class PPP 

 Collectively, the certificates will represent all beneficial interests in
the property owned by the Trust, legal title to which will be held by the Trust.
The certificates will have the following designations:                          

                                                        [Enlarge/Download Table]
                                                                                           
Class A Certificates......................... Class A-1A, Class A-1B1, Class A-1B2,        
                                              Class A-1B3, Class A-1C1, Class A-1C2,       
                                              Class A-1C3 and Class A-1C4 Certificates.    

Senior Certificates.......................... Class A, Class X and Class R Certificates.   

Senior Subordinate Certificates.............. Class B-1, Class B-2, Class B-3, Class B-4,  
                                              Class B-5, Class B-6 Class B-7, Class B-8 and
                                              Class B-9 Certificates.                      

Junior Subordinate Certificates.............. Class B-10, Class B-11, Class B-12 and       
                                              Class B-13 Certificates.                     

Class B or Subordinate Certificates.......... Senior Subordinate and Junior Subordinate    
                                              Certificates.                                

Residual Certificates........................ Class R Certificates.                        

Regular Certificates......................... All classes of certificates other than the   
                                              Class R and Class PPP Certificates.          

LIBOR Certificates........................... Class A and Class B Certificates.            

Physical Certificates........................ Junior Subordinate, Class R and Class PPP    
                                              Certificates.                                

Book-Entry Certificates...................... All classes of certificates other than the   
                                              Physical Certificates.                       

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   Only the Senior and the Senior Subordinate Certificates, called the offered
certificates, are offered by this prospectus supplement. The Junior Subordinate 
and Class PPP Certificates are not offered by this prospectus supplement.       

   The 'CLASS PRINCIPAL BALANCE' for any Distribution Date (as defined in this
prospectus supplement) and for any class of certificates or the Class X         
principal-only component, as applicable, will equal the aggregate amount of     
principal to which it is entitled on the Closing Date, reduced by all           
distributions of principal to that class or component, as applicable, and all   
allocations of losses required to be borne by that class or component, as       
applicable, before that Distribution Date and increased by the portion of the   
aggregate Net Negative Amortization (as defined in ' -- Distributions of        
Interest' in this prospectus supplement) allocated to that class or component,  
as applicable, as described in ' -- Distributions of Interest' in this          
prospectus supplement. See 'Description of the Certificates' in this prospectus 
supplement.                                                                     

   The 'CERTIFICATE PRINCIPAL BALANCE' for any certificate will be the portion
of the corresponding Class Principal Balance that it represents; provided,      
however, that each Class X Certificate will represent a portion of the Class X  
Principal Balance (as described in ' -- Distributions of Interest -- Class X    
Notional Amount and Class X Principal Balance' in this prospectus supplement)   
equal to its percentage interest in the notional amount of the Class X          
Certificates.                                                                   

  Solely for purposes of calculating distributions of principal and interest
and the allocation of losses realized on the mortgage loans, the Class X        
Certificates will be deemed to be comprised of an interest-only component and a 
principal-only component. The Class X Certificates will accrue interest on the  
Class X Notional Amount, calculated as described in this prospectus supplement  
under ' -- Distributions of Interest -- Class X Notional Amount and Class X     
Principal Balance.' In addition, the Class X Certificates will have a principal 
balance, which will equal the aggregate Class Principal Balance of the Class X  
principal-only component and which will initially equal zero. In the event that 
interest accrued on the Class X Notional Amount is reduced as a result of Net   
Negative Amortization, such amount will be added as principal to the outstanding
component principal balance of the Class X principal-only component, in an      
amount equal to the amount of Net Negative Amortization attributable to the     
mortgage loans. The holders of the Class X Certificates will be entitled to     
receive principal and interest distributions on any Distribution Date to the    
extent of the amount of interest and principal distributed with respect to the  
Class X Notional Amount and the Class X Principal Balance, respectively.        
Interest will not accrue on the Class X Principal Balance.                      

The Senior Certificates will comprise approximately 90.75%, the Senior  
Subordinate Certificates will comprise approximately 6.95%, and the Junior      
Subordinate Certificates will comprise approximately 2.30% of the aggregate     
principal balance of the mortgage loans as of the Cut-Off Date.                 

  The offered certificates, other than the Class X and Class R Certificates,
are each offered in minimum denominations equivalent to not less than $25,000   
each and multiples of $1 in excess of that amount.                              

   The Class X Certificates are offered in minimum denominations equivalent to
not less than $100,000 initial Class X Notional Amount each and multiples of $1 
in excess of that amount.                                                       

The Class R Certificates will have an initial Class Principal Balance of
$100 and will be offered in registered, certificated form in a single           
denomination of a 99.99% percentage interest. The remaining 0.01% percentage    
interest of the Class R Certificates will be owned by Washington Mutual Bank as 
described in this prospectus supplement under 'Certain Federal Income Tax       
Consequences.'                                                                  

BOOK-ENTRY REGISTRATION                                                         

Each class of Book-Entry Certificates will initially be represented by a
single certificate registered in the name of Cede & Co. ('CEDE'), a nominee of  
The Depository Trust Company, New York, New York ('DTC'). Cede will be the      
record holder of the Book-Entry Certificates, but references to 'Book-Entry     
Certificateholders' should be understood to be references to the persons on     
whose account DTC will be causing Cede to hold the Book-Entry Certificates. No  
Book-Entry Certificateholder will be entitled to receive a registered           
certificate. Unless registered certificates are issued under the limited        
circumstances described in this prospectus supplement, all references to actions
by Book-Entry Certificateholders refer to actions taken by DTC participants as  
described below, and all references in this prospectus supplement to            

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distributions, notices, reports, and statements to Book-Entry Certificateholders
refer to distributions, notices, reports, and statements to Cede, as the        
registered holder of those certificates, for distribution to Book-Entry         
Certificateholders in accordance with DTC procedures.                           

 Certificateholders may hold their Book-Entry Certificates through DTC, if
they are DTC participants, or indirectly through organizations that are DTC     
participants, including Euroclear Bank S.A./N.V. ('EUROCLEAR') or Clearstream   
Banking, societe anonyme ('CLEARSTREAM'), as described below. Transfers between 
DTC participants will occur in accordance with DTC rules. Cede, as nominee of   
DTC, will be the named certificateholder of the registered certificates for the 
Book-Entry Certificates. Euroclear and Clearstream will hold omnibus positions  
on behalf of their participants through customers' securities accounts in       
Euroclear's and Clearstream's names on the books of their respective            
depositaries which in turn will hold the positions in customers' securities     
accounts in the depositaries' names on the books of DTC.                        

DTC has advised Washington Mutual Mortgage Securities Corp. that it is a
limited-purpose trust company organized under the New York Banking Law, a       
'banking organization' within the meaning of the New York Banking Law, a member 
of the Federal Reserve System, a 'clearing corporation' within the meaning of   
the New York Uniform Commercial Code and a 'clearing agency' registered pursuant
to the provisions of Section 17A of the Securities Exchange Act of 1934, as     
amended.                                                                        

DTC holds securities that its participants deposit with DTC. DTC also   
facilitates the settlement among DTC participants of securities transactions,   
such as transfers and pledges, in deposited securities through electronic       
computerized book-entry changes in DTC participants' accounts, which eliminates 
the need for physical movement of securities. DTC participants include the      
underwriters, securities brokers and dealers, banks, trust companies, clearing  
corporations and similar organizations. Indirect access to the DTC system is    
also available to other entities, referred to as indirect DTC participants, such
as banks, brokers, dealers, and trust companies that clear through or maintain a
custodial relationship with a DTC participant, either directly or indirectly.   

Certificateholders that are not DTC participants or indirect DTC        
participants but desire to purchase, sell, or otherwise transfer ownership of or
other interests in Book-Entry Certificates may do so only through DTC           
participants and indirect DTC participants. In addition, unless registered      
certificates are issued, certificateholders will receive all distributions of   
principal and interest on the Book-Entry Certificates through DTC participants. 
Under a book-entry format, certificateholders will receive payments after the   
related Distribution Date because, although payments are required to be         
forwarded to Cede, as nominee for DTC, on each Distribution Date, DTC will      
forward payments to DTC participants, which will then be required to forward    
them to indirect DTC participants or certificateholders. Payments on            
certificates held through Euroclear or Clearstream will be credited to the cash 
accounts of Euroclear participants or Clearstream participants in accordance    
with the relevant system's rules and procedures, to the extent received by the  
relevant depositary. The payments will be subject to tax reporting in accordance
with relevant United States tax laws and regulations.                           

    It is anticipated that the sole 'Certificateholder' (as that term is used in
the pooling agreement) for each class of Book-Entry Certificates will be Cede,  
as nominee of DTC, and that Book-Entry Certificateholders will not be recognized
by the trustee as certificateholders under the pooling agreement. Book-Entry    
Certificateholders will be permitted to exercise the rights of                  
certificateholders under the pooling agreement only indirectly through DTC      
participants, who in turn will exercise their rights through DTC.               

  Under the rules, regulations and procedures creating and affecting DTC and
its operations, DTC is required to make book-entry transfers among DTC          
participants on whose behalf it acts for the Book-Entry Certificates and is     
required to receive and transmit payments of principal and interest, if any, on 
the Book-Entry Certificates. DTC participants and indirect DTC participants with
whom Book-Entry Certificateholders have accounts for the Book-Entry Certificates
similarly are required to make book-entry transfers and receive and transmit    
payments on behalf of their respective Book-Entry Certificateholders.           
Accordingly, although owners of Book-Entry Certificates will not possess        
registered certificates, the DTC rules provide a mechanism by which owners of   
the Book-Entry Certificates through their DTC participants will receive payments
and will be able to transfer their interest.                                    

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    DTC can only act on behalf of DTC participants, who in turn act on behalf of
indirect DTC participants and certain banks. Therefore, the ability of a        
Book-Entry Certificateholder to pledge Book-Entry Certificates to persons or    
entities that do not participate in the DTC system, or to take other actions in 
respect of Book-Entry Certificates, may be limited due to the lack of a physical
certificate for Book-Entry Certificates.                                        

Neither DTC, Cede nor any other DTC nominee will consent or vote for the
Book-Entry Certificates. Rather, DTC will assign Cede's consenting or voting    
rights to those DTC participants to whose accounts the Book-Entry Certificates  
are credited at the relevant time. The Euroclear Operator or Clearstream, as the
case may be, will take any other action permitted to be taken by                
certificateholders under the pooling agreement on behalf of a Euroclear         
participant or Clearstream participant only in accordance with its relevant     
rules and procedures and subject to the ability of the relevant depositary to   
effect the actions on its behalf through DTC.                                   

   The Book-Entry Certificates are only offered for sale in the United States.
To the extent that non-United States persons acquire a beneficial interest in   
any of the Book-Entry Certificates, however, they will be able to hold through  
Euroclear or Clearstream. Euroclear and Clearstream will hold interests on      
behalf of their participants through customers' securities accounts in          
Euroclear's and Clearstream's names on the books of the depositaries that serve 
Euroclear and Clearstream. Those depositaries, in turn, will hold those         
interests in customers' securities accounts in the depositaries' names on the   
books of DTC.                                                                   

Euroclear advises that it was created in 1968 to hold securities for    
participants of Euroclear and to clear and settle transactions between Euroclear
participants through simultaneous electronic book-entry delivery against        
payment, eliminating the need for physical movement of certificates and any risk
from lack of simultaneous transfers of securities and cash. Transactions may now
be settled in many currencies, including United States dollars and Japanese yen.
Euroclear provides various other services, including securities lending and     
borrowing and interfaces with domestic markets in several countries generally   
similar to the arrangements for cross-market transfers with DTC described below.

Euroclear is operated by Euroclear Bank S.A./N.V. (the 'EUROCLEAR       
OPERATOR'), under contract with Euroclear Clearance System plc, a U.K.          
corporation (the 'EUROCLEAR CLEARANCE SYSTEM'). The Euroclear Operator conducts 
all operations, and all Euroclear securities clearance accounts and Euroclear   
cash accounts are accounts with the Euroclear Operator, not the Euroclear       
Clearance System. The Euroclear Clearance System establishes policy for         
Euroclear on behalf of Euroclear participants. Euroclear participants include   
banks (including central banks), securities brokers and dealers and other       
professional financial intermediaries and may include the underwriters. Indirect
access to Euroclear is also available to other firms that clear through or      
maintain a custodial relationship with a Euroclear participant, either directly 
or indirectly. Euroclear is an indirect participant in DTC.                     

    The Euroclear Operator is a Belgian bank. The Belgian Banking Commission and
the National Bank of Belgium regulate and examine the Euroclear Operator.       

The terms and conditions governing use of Euroclear and the related     
operating procedures of Euroclear and applicable Belgian law govern securities  
clearance accounts and cash accounts with the Euroclear Operator. Specifically, 
these terms and conditions govern:                                              

transfers of securities and cash within Euroclear;    

withdrawal of securities and cash from Euroclear; and 

receipts of payments with respect to securities in    
Euroclear.                                            

    All securities in Euroclear are held on a fungible basis without attribution
of specific certificates to specific securities clearance accounts. The         
Euroclear Operator acts under the terms and conditions only on behalf of        
Euroclear participants and has no record of or relationship with persons holding
securities through Euroclear participants.                                      

Distributions with respect to Book-Entry Certificates held beneficially 
through Euroclear will be credited to the cash accounts of Euroclear            
participants in accordance with the Euroclear Terms and Conditions, to the      
extent received by the Euroclear Operator and by Euroclear.                     

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    Clearstream was incorporated as a limited liability company under Luxembourg
law. Clearstream is owned by Deutsche Borse AG, the shareholders of which are   
banks, securities dealers and financial institutions.                           

    Clearstream holds securities for its customers and facilitates the clearance
and settlement of securities transactions between Clearstream customers through 
electronic book-entry changes in accounts of Clearstream customers, thus        
eliminating the need for physical movement of certificates. Clearstream provides
to its customers, among other things, services for safekeeping, administration, 
clearance and settlement of internationally traded securities, securities       
lending and borrowing and collateral management. Clearstream interacts with     
domestic markets in a number of countries. Clearstream has established an       
electronic bridge with the Euroclear Operator to facilitate settlement of trades
between Clearstream and Euroclear.                                              

   As a registered bank in Luxembourg, Clearstream is subject to regulation by
the Luxembourg Commission for the Supervision of the Financial Sector.          
Clearstream customers are recognized financial institutions around the world,   
including underwriters, securities brokers and dealers, banks, trust companies  
and clearing corporations. In the United States, Clearstream customers are      
limited to securities brokers and dealers and banks, and may include the        
underwriters for the Book-Entry Certificates. Other institutions that maintain a
custodial relationship with a Clearstream customer may obtain indirect access to
Clearstream. Clearstream is an indirect participant in DTC.                     

   Distributions with respect to the Book-Entry Certificates held beneficially
through Clearstream will be credited to cash accounts of Clearstream customers  
in accordance with its rules and procedures, to the extent received by          
Clearstream.                                                                    

 Title to book-entry interests in the Book-Entry Certificates will pass by
book-entry registration of the transfer within the records of Euroclear,        
Clearstream or DTC, as the case may be, in accordance with their respective     
procedures. Book-entry interests in the Book-Entry Certificates may be          
transferred within Euroclear and within Clearstream and between Euroclear and   
Clearstream in accordance with procedures established for these purposes by     
Euroclear and Clearstream. Book-entry interests in the Book-Entry Certificates  
may be transferred within DTC in accordance with procedures established for this
purpose by DTC. Transfers of book-entry interests in the Book-Entry Certificates
between Euroclear and Clearstream and DTC may be effected in accordance with    
procedures established for this purpose by Euroclear, Clearstream and DTC.      

Initial settlement for the Book-Entry Certificates will be made in      
immediately available funds. Secondary market trading between DTC participants  
will occur in the ordinary way in accordance with DTC rules and will be settled 
in immediately available funds. Secondary market trading between Euroclear      
participants and/or Clearstream participants will occur in the ordinary way in  
accordance with the applicable rules and operating procedures of Euroclear and  
Clearstream and will be settled using the procedures applicable to conventional 
Eurobonds in immediately available funds.                                       

Cross-market transfers between persons holding directly or indirectly   
through DTC on the one hand, and directly or indirectly through Euroclear or    
Clearstream participants, on the other, will be effected by DTC in accordance   
with DTC rules on behalf of the relevant European international clearing system 
by its respective depositary in the United States. However, those cross-market  
transactions will require delivery of instructions to the relevant European     
international clearing system by the counterparty in such system in accordance  
with its rules and procedures and within its established deadlines (European    
time). The relevant European international clearing system will, if the         
transaction meets its settlement requirements, deliver instructions to its U.S. 
depository to take action to effect final settlement on its behalf by delivering
or receiving Book-Entry Certificates to or from DTC, and making or receiving    
payment in accordance with normal procedures for same-day funds settlement      
applicable to DTC. Euroclear participants and Clearstream participants may not  
deliver instructions directly to their respective depositaries in the United    
States.                                                                         

Because of time-zone differences, credits of Book-Entry Certificates    
received in Euroclear or Clearstream as a result of a transaction with a DTC    
participant will be made during subsequent securities settlement processing and 
dated the business day following the DTC settlement date. These credits or any  
transactions in such Book-Entry Certificates settled during such processing will
be reported to the relevant                                                     

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Euroclear or Clearstream participants on that business day. Cash received in    
Euroclear or Clearstream as a result of sales of Book-Entry Certificates by or  
through a Euroclear participant or a Clearstream participant to a DTC           
participant will be received with value on the DTC settlement date but will be  
available in the relevant Euroclear or Clearstream cash account only as of the  
business day following settlement in DTC.                                       

Although DTC, Euroclear and Clearstream have agreed to the foregoing    
procedures in order to facilitate transfers of certificates among participants  
of DTC, Euroclear and Clearstream, they are under no obligation to perform or   
continue to perform the procedures and the procedures may be discontinued at any
time. See 'Appendix C' to this prospectus supplement.                           

 For a discussion of certain federal income tax consequences applicable to
holders of Book-Entry Certificates who hold such certificates through           
Clearstream or Euroclear, or through DTC if the holder has an address outside   
the U.S., see Appendix C to this prospectus supplement.                         

DEFINITIVE CERTIFICATES                                                         

    The Book-Entry Certificates will be issued in fully registered, certificated
form to certificateholders or their nominees, rather than to DTC or its nominee,
only if:                                                                        

  DTC advises the trustee in writing that DTC is no longer
    willing or able to discharge properly its responsibilities
as depository for the Book-Entry Certificates and the 
 trustee or the servicer is unable to locate a qualified
successor;                                            

The servicer, with the consent of the related DTC     
 participants, elects to terminate the book-entry system
through DTC; or                                       

after the occurrence of an event of default under the 
pooling agreement, certificateholders of Book-Entry   
Certificates evidencing not less than 66 2/3% of the  
    aggregate outstanding Certificate Principal Balance advise
      the trustee and DTC through DTC participants in writing that
     the continuation of a book-entry system through DTC (or its
successor) is no longer in the best interest of the   
certificateholders.                                   

If any of the above events occur, DTC is required to notify all DTC     
participants of the availability of registered certificates. When DTC surrenders
its physical certificates and provides instructions for re-registration, the    
trustee will issue registered certificates to replace the Book-Entry            
Certificates. After that happens, the trustee will recognize the holders of     
those registered certificates as certificateholders under the pooling agreement.

The trustee or its paying agent, if any, will make distributions of     
principal and interest on the registered certificates directly to holders of    
those registered certificates in accordance with the pooling agreement          
procedures described in this prospectus supplement. Distributions of principal  
and interest on each Distribution Date will be made to holders in whose names   
certificates were registered at the close of business on the related record     
date. Distributions will be made by wire transfer in immediately available funds
for the account of each holder or, if a holder has not provided wire            
instructions, by check mailed to the address of the holder as it appears on the 
register maintained by the certificate registrar. The final payment on any      
certificate will be made only on presentation and surrender of the certificate  
at the offices of the trustee or its agent or such office or agency as is       
specified in the notice of final distribution to holders of certificates being  
retired. When the trustee receives notice from the servicer that it believes the
remaining unpaid principal balance of a class of certificates will be           
distributable on the next Distribution Date, the trustee is required to provide 
notice to registered certificateholders of that class not later than the        
eighteenth day of the month in which that class will be retired.                

   Registered certificates will be transferable and exchangeable at the office
or agency of the trustee at 'DB Services Tennessee, 648 Grassmere Park Road,    
Nashville, TN 37211-3658, Attn: Transfer Unit.' A reasonable service charge may 
be imposed for any registration of transfer or exchange, and the trustee or its 
agent may require payment of a sum sufficient to cover any tax or other         
governmental charge imposed in connection with registration of transfer or      
exchange.                                                                       

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PRIORITY OF DISTRIBUTIONS                                                       

  Beginning in September 2005, on the 25th day of each month, or if the 25th
day is not a business day, on the immediately following business day (each, a   
'DISTRIBUTION DATE'), before the Credit Support Depletion Date (as defined in   
this prospectus supplement), to the extent of the Available Distribution Amount 
(as defined in this prospectus supplement) for that Distribution Date and,      
solely with respect to clause (iv)(a), amounts paid pursuant to the Yield       
Maintenance Agreement, distributions will be made to the certificateholders in  
the order and priority as follows:                                              

   (i)    first, to the Class A, Class X and Class R Certificates, pro rata,
            accrued and unpaid interest at their respective certificate interest
       rate on their respective Class Principal Balance or the Class X
Notional Amount, as applicable; provided, however, that,
       notwithstanding the foregoing, amounts to be distributed to the
         Class X Certificates in respect of accrued interest (after giving
        effect to any Net Negative Amortization allocated to the Class X
        Certificates and any shortfall in interest collections resulting
         from Curtailments (as defined in this prospectus supplement), the
    timing of Payoffs (to the extent not covered by compensating
           interest) and the Relief Act allocated to the Class X Certificates)
            (the 'CLASS X DISTRIBUTABLE INTEREST') will be reduced to the extent
          necessary to pay any Carryover Shortfall Amount not covered by the
        Yield Maintenance Agreement (as defined in ' -- Distributions of
  Interest -- Carryover Shortfall Amount' in this prospectus
           supplement) to the Class A Certificates, and any remaining amounts,
            to the extent necessary to pay any Carryover Shortfall Amount to the
            Class B Certificates, as applicable, pursuant to clauses (iv)(b) and
(xxiv) below, respectively;                             

     (ii)   second, to the Class R Certificates, as principal, until the Class R
Principal Balance has been reduced to zero;             

(iii)   third, to the Class A Certificates and Class X principal-only   
          component, as principal, the Senior Principal Distribution Amount,
           in the order described in ' -- Distributions of Principal -- Senior
     Principal Distribution Amount' in this prospectus supplement;

    (iv)   fourth, to the Class A Certificates, the Carryover Shortfall Amount
         for each such class, pro rata based on unpaid Carryover Shortfall
          Amounts, (a) first, to the extent available from payments pursuant
           to the Yield Maintenance Agreement and (b) second, to the extent of
the Class X Distributable Interest;                     

      (v)   fifth, to the Class B-1 Certificates, accrued and unpaid interest at
           their certificate interest rate on the Class B-1 Principal Balance;

  (vi)   sixth, to the Class B-1 Certificates, their pro rata share of the
Subordinate Principal Distribution Amount;              

    (vii)  seventh, to the Class B-2 Certificates, accrued and unpaid interest
     at their certificate interest rate on the Class B-2 Principal
Balance;                                                

  (viii)  eighth, to the Class B-2 Certificates, their pro rata share of the
Subordinate Principal Distribution Amount;              

     (ix)   ninth, to the Class B-3 Certificates, accrued and unpaid interest at
           their certificate interest rate on the Class B-3 Principal Balance;

   (x)   tenth, to the Class B-3 Certificates, their pro rata share of the
Subordinate Principal Distribution Amount;              

     (xi)   eleventh, to the Class B-4 Certificates, accrued and unpaid interest
     at their certificate interest rate on the Class B-4 Principal
Balance;                                                

    (xii)  twelfth, to the Class B-4 Certificates, their pro rata share of the
Subordinate Principal Distribution Amount;              

(xiii)  thirteenth, to the Class B-5 Certificates, accrued and unpaid   
    interest at their certificate interest rate on the Class B-5
Principal Balance;                                      

   (xiv)  fourteenth, to the Class B-5 Certificates, their pro rata share of
the Subordinate Principal Distribution Amount;          

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(xv)  fifteenth, to the Class B-6 Certificates, accrued and unpaid  
    interest at their certificate interest rate on the Class B-6
Principal Balance;                                      

  (xvi)  sixteenth, to the Class B-6 Certificates, their pro rata share of
the Subordinate Principal Distribution Amount;          

(xvii) seventeenth, to the Class B-7 Certificates, accrued and unpaid 
    interest at their certificate interest rate on the Class B-7
Principal Balance;                                      

  (xviii) eighteenth, to the Class B-7 Certificates, their pro rata share of
the Subordinate Principal Distribution Amount;          

(xix)  nineteenth, to the Class B-8 Certificates, accrued and unpaid  
    interest at their certificate interest rate on the Class B-8
Principal Balance;                                      

   (xx)  twentieth, to the Class B-8 Certificates, their pro rata share of
the Subordinate Principal Distribution Amount;          

(xxi)  twenty-first, to the Class B-9 Certificates, accrued and unpaid
    interest at their certificate interest rate on the Class B-9
Principal Balance;                                      

   (xxii) twenty-second, to the Class B-9 Certificates, their pro rata share
of the Subordinate Principal Distribution Amount;       

  (xxiii) twenty-third, to the Junior Subordinate Certificates, interest and
  principal in the same manner as for the Senior Subordinate
       Certificates, first to the Class B-10 Certificates, then to the
        Class B-11 Certificates, then to the Class B-12 Certificates and
then to the Class B-13 Certificates;                    

 (xxiv) twenty-fourth, to each class of Class B Certificates in order of
         seniority, the Carryover Shortfall Amount for each such class, to
            the extent of the Class X Distributable Interest remaining after the
distributions pursuant to clause (iv)(b) above;         

(xxv) twenty-fifth, to the Class A Certificates and the Class X     
       principal-only component, pro rata according to Class Principal
     Balance, as applicable, and then to each class of Subordinate
            Certificates in order of seniority, up to the amount of unreimbursed
        realized principal losses previously allocated to that class, if
        any; provided, however, that any amounts distributed pursuant to
         this clause (xxv) will not cause a further reduction in the Class
Principal Balances of any of the certificates; and      

(xxvi) twenty-sixth, to the Class R Certificates.                     

Notwithstanding the above, amounts to be distributed to each class of   
certificates in respect of accrued interest on any Distribution Date will be    
reduced by the amount of Net Negative Amortization, if any, allocated to that   
class. In addition, notwithstanding the immediately preceding paragraph, on any 
Distribution Date on which the Subordination Level (as defined below) for any   
class or classes of Subordinate Certificates is less than the Subordination     
Level as of the Closing Date, a different distribution will be made. The amount 
of the Subordinate Principal Prepayments Distribution Amount (as defined in this
prospectus supplement), if any, otherwise allocable to such class or classes    
will be allocated to the more senior classes of the Subordinate Certificates,   
pro rata according to the Class Principal Balances of those classes.            

 With respect to any class of Subordinate Certificates, the 'SUBORDINATION
LEVEL' on any specified date is the percentage obtained by dividing the sum of  
the Class Principal Balances of that class and all classes of Subordinate       
Certificates that are subordinate in right of payment to that class by the sum  
of the Class Principal Balances of all classes of certificates as of that date  
before giving effect to distributions and allocations of realized losses to the 
certificates on that date.                                                      

   The 'CREDIT SUPPORT DEPLETION DATE' is the first Distribution Date on which
the aggregate Class Principal Balance of the Class B Certificates has been or   
will be reduced to zero.                                                        

On each Distribution Date on or after the Credit Support Depletion Date,
distributions of the Available Distribution Amount will be made with respect to 
the certificates as follows:                                                    

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    (i)  first, to the Class A and Class X Certificates, pro rata, accrued and
          unpaid interest at their respective certificate interest rate on their
     respective Class Principal Balance or Class X Notional Amount, as
          applicable; provided, however, that notwithstanding the foregoing, the
          Class X Distributable Interest will be reduced to the extent necessary
  to pay any Carryover Shortfall Amount not covered by the Yield
        Maintenance Agreement to the Class A Certificates pursuant to clause
(iii)(b) below;                                             

     (ii) second, to the Class A and Class X principal-only component, pro rata,
as principal, the Senior Principal Distribution Amount;     

    (iii) third, to the Class A Certificates, the Carryover Shortfall Amount for
          each such class, pro rata based on unpaid Carryover Shortfall Amounts,
          (a) first, to the extent available from payments pursuant to the Yield
      Maintenance Agreement and (b) second, to the extent of the Class X
Distributable Interest; and                                 

(iv) fourth, to the Class R Certificates.                             

Notwithstanding the above, amounts to be distributed to each class of   
certificates in respect of accrued interest on any Distribution Date will be    
reduced by the amount of Net Negative Amortization, if any, allocated to that   
class.                                                                          

DISTRIBUTIONS OF INTEREST                                                       

For each class of certificates (other than the Class PPP Certificates), 
interest will be passed through monthly on each Distribution Date, beginning in 
September 2005. The amount of interest each class of Class A Certificates       
accrues during each certificate accrual period will equal a ratio, the numerator
of which is the actual number of days in that accrual period and the denominator
of which is 360, multiplied by the annual certificate interest rate in effect   
for that accrual period for that class, and the amount of interest the Class X  
Certificates and each class of Subordinate Certificates accrues during each     
certificate accrual period will equal 1/12th of the annual certificate interest 
rate in effect for that accrual period for that class, in each case, multiplied 
by the related Class Principal Balance or Class X Notional Amount, as           
applicable, less any prepayment interest shortfalls not covered by Compensating 
Interest (as described below in ' -- Compensating Interest'), any interest      
shortfalls relating to the Relief Act and any Net Negative Amortization         
allocated to that class of certificates; provided, however, the amount of       
interest to be distributed to the certificates may be adjusted as described in  
' -- Carryover Shortfall Amounts' in this prospectus supplement. The Class PPP  
Certificates will not accrue interest.                                          

  The 'ADJUSTED CAP RATE' for any Distribution Date and any class of Class A
Certificates will equal a fraction, the numerator of which is equal to the      
product of (i) the amount of interest accrued on the mortgage loans at the      
Weighted Average Pass-Through Rate for that Distribution Date less the Net      
Negative Amortization and (ii) 12, and the denominator of which is the aggregate
principal balance of the mortgage loans as of the second preceding Due Date     
after giving effect to the payments due on the mortgage loans on that Due Date, 
such fraction multiplied by a ratio, the numerator of which is 30 and the       
denominator of which is the actual number of days in the related certificate    
accrual period. The Adjusted Cap Rate for any Distribution Date and any class of
Class B Certificates will equal the Weighted Average Pass-Through Rate, computed
for this purpose by (i) reducing the Weighted Average Pass-Through Rate by a per
annum rate equal to a fraction, the numerator of which is the Net Negative      
Amortization with respect to the mortgage loans multiplied by 12, and the       
denominator of which is the aggregate principal balance of the mortgage loans as
of the second preceding Due Date after giving effect to the payments due on the 
mortgage loans on that Due Date.                                                

The 'NET NEGATIVE AMORTIZATION' for any Distribution Date will equal the
excess, if any, of (i) the aggregate amount of negative amortization with       
respect to all mortgage loans during the prior calendar month, over (ii) the    
aggregate amount of Payoffs and Curtailments received with respect to all       
mortgage loans during the related Prepayment Period.                            

  For any Distribution Date, the Net Negative Amortization will be allocated
first to the Class X Certificates until the interest otherwise payable to the   
Class X Certificates is reduced to zero, and then among the classes of          
certificates in proportion to the excess, if any, for each such class of (i) the
current interest accrued at the applicable certificate interest rate for such   
class, over (ii) the amount of current                                          

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interest that would have accrued had the certificate interest rate for such     
class equaled the related Adjusted Cap Rate for such class and for such         
Distribution Date. The Class Principal Balance of each class of LIBOR           
Certificates will be increased by the portion of the Net Negative Amortization  
allocated to such class in reduction of interest distributable to such class.   
With respect to the Class X Certificates, any amount of Net Negative            
Amortization that is allocated to the Class X Notional Amount will be added as  
principal to the outstanding component principal balance of the Class X         
principal-only component in an amount equal to the amount of Net Negative       
Amortization attributable to the mortgage loans. As a result of the allocation  
of Net Negative Amortization, a portion of the interest accrued on the          
certificates may be distributed to the certificates later than otherwise        
anticipated.                                                                    

Interest to be distributed on the applicable classes of certificates (or
added to the Class Principal Balance of the certificates as a result of the     
allocation of Net Negative Amortization) on any Distribution Date will consist  
of accrued and unpaid interest as of previous Distribution Dates and interest   
accrued during the period beginning on the 25th day of the preceding calendar   
month (or, in the case of the first Distribution Date, the Closing Date) and    
ending on the 24th day of the month of that Distribution Date, except for the   
Class X Certificates, which accrue interest on the Class X Notional Amount,     
during the preceding calendar month. Interest to be distributed on the Class A  
Certificates will be calculated based on the actual number of days in the       
certificate accrual period and assuming a 360 day year. Interest to be          
distributed on the Class X and Subordinate Certificates, will be calculated     
based on a year consisting of twelve thirty-day months. All distributions of    
interest for each class of certificates (other than the Class PPP Certificates) 
will generally be made only to the extent of the Available Distribution Amount  
as described under ' -- Priority of Distributions' in this prospectus           
supplement.                                                                     

The annual certificate interest rates for the offered certificates are  
listed in the table on page S-4 of this prospectus supplement and in the notes  
to that table.                                                                  

The 'PASS-THROUGH RATE' for each mortgage loan is equal to the per annum
mortgage interest rate on that mortgage loan less the servicing fee rate (as    
described in this prospectus supplement under ' -- Servicing Compensation and   
Payment of Expenses').                                                          

   The 'ADJUSTED WEIGHTED AVERAGE PASS-THROUGH RATE' for any Distribution Date
is the product of (i) the weighted average of the Pass-Through Rates of the     
mortgage loans as of the second preceding Due Date after giving effect to the   
payments due on the mortgage loans on that Due Date and (ii) a fraction, the    
numerator of which is 30 and the denominator of which is the actual number of   
days in the related certificate accrual period.                                 

 The 'WEIGHTED AVERAGE PASS-THROUGH RATE' for any Distribution Date is the
weighted average of the Pass-Through Rates of the mortgage loans as of the      
second preceding Due Date after giving effect to the payments due on the        
mortgage loans on that Due Date.                                                

Class X Notional Amount and Class X Principal Balance                   

The Class X Certificates will accrue interest on the Class X Notional   
Amount. The 'CLASS X NOTIONAL AMOUNT' for any Distribution Date will equal the  
aggregate principal balance of the mortgage loans as of the second preceding Due
Date after giving effect to the payments due on the mortgage loans on that Due  
Date. The Class X Notional Amount as of the Closing Date will be approximately  
$3,201,069,294. Interest will not accrue on the Class X Principal Balance.      

    The Class X Certificates will have a principal balance, which will equal the
Class X principal-only component and which will initially equal zero. In the    
event that interest accrued on the Class X Notional Amount is reduced as a      
result of Net Negative Amortization, such amount will be added as principal to  
the outstanding component principal balance of the Class X principal-only       
component. Interest will not accrue on the Class X Principal Balance.           

Compensating Interest                                                   

Washington Mutual Bank, as servicer, is obligated to remit to the       
Certificate Account on the business day before each Distribution Date an amount 
equal to the least of (a) any shortfall for the previous month in interest      
collections resulting from the timing of Payoffs (as defined in this prospectus 
supplement) made                                                                

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from the 15th day of the calendar month preceding the Distribution Date to the  
last day of the month, (b) the sum of (i) 1/12 of 0.050% of the aggregate Stated
Principal Balance of the mortgage loans, (ii) any reinvestment income realized  
by the servicer relating to Payoffs made during the Prepayment Period (as       
defined in this prospectus supplement) and (iii) interest payments on Payoffs   
received during the period of the first day through the 14th day of the month of
the Distribution Date and (c) 1/12 of 0.125% of the aggregate Stated Principal  
Balance of the mortgage loans. Compensating Interest will be added to the       
Available Distribution Amount.                                                  

   Any remaining shortfall in interest collections resulting from Curtailments
(as defined in this prospectus supplement), the timing of Payoffs and the Relief
Act, and any interest shortfall resulting from negative amortization, will be   
allocated to the certificates of a class pro rata according to the amount of    
interest to which each such certificate would otherwise be entitled (before     
giving effect to the payment of Carryover Shortfall Amounts), in reduction of   
that amount.                                                                    

   See 'Yield and Prepayment Considerations' in this prospectus supplement and
'Yield Considerations -- Effective Interest Rate' in the prospectus.            

Carryover Shortfall Amounts                                             

   For any Distribution Date and for any class of Class A Certificates and any
class of Class B Certificates, the 'CARRYOVER SHORTFALL AMOUNT' for such class  
will equal the sum of:                                                          

(i)  the excess, if any, of (a) the amount of interest that would have
     accrued on such class at a certificate interest rate equal to the
        lesser of (1) LIBOR plus the related margin and (2) 10.50%, over (b)
the actual amount of interest accrued on such class for such
Distribution Date;                                          

(ii) the portion of the amount described in clause (i) above remaining
unpaid from prior Distribution Dates; and                   

  (iii) one month's interest at the rate described in clause (i)(a) above on
the amount described in clause (ii) above.                  

Carryover Shortfall Amounts will be paid to holders of the Class A      
Certificates, pro rata based on unpaid Carryover Shortfall Amounts, first, from 
payments pursuant to the Yield Maintenance Agreement and, second, to the extent 
of the Class X Distributable Interest that would otherwise be payable to the    
Class X Certificates. See ' -- Priority of Distributions' in this prospectus    
supplement. Carryover Shortfall Amounts will be paid to holders of the Class B  
Certificates, in order of seniority, to the extent of any remaining Class X     
Distributable Interest. See ' -- Priority of Distributions' in this prospectus  
supplement.                                                                     

The amounts to be distributed to the Class X Certificates in respect of 
accrued interest will be reduced by the aggregate Carryover Shortfall Amounts   
paid to the holders of the Class A and Class B Certificates.                    

The Yield Maintenance Agreement                                         

    The Trust will have the benefit of a yield maintenance agreement (the 'YIELD
MAINTENANCE AGREEMENT') between the Trust and Bear Stearns Financial Products   
Inc. (the 'CAP COUNTERPARTY'), entered into on or before the Closing Date, which
is intended to partially mitigate the risk to the Class A Certificates that     
LIBOR plus the related margin will exceed the Adjusted Weighted Average         
Pass-Through Rate. On each Distribution Date, payments under the Yield          
Maintenance Agreement will equal the product of (i) a fraction, the numerator of
which is the actual number of days in the accrual period and the denominator of 
which is 360, (ii) the excess, if any, of (x) LIBOR, subject to a maximum of    
10.17%, over (y) the related cap strike rate and (iii) the lesser of (x) the    
aggregate Class Principal Balance of the Class A Certificates and (y) the       
related Yield Maintenance Notional Balance. The 'YIELD MAINTENANCE NOTIONAL     
BALANCE' and related cap strike rate on each Distribution Date is as described  
in Schedule 1 to this prospectus supplement. Payments, if any, made pursuant to 
the Yield Maintenance Agreement will start on the Distribution Date in October  
2005. After the Distribution Date in February 2014, the Yield Maintenance       
Notional Balance will be equal to zero and the Yield Maintenance Agreement will 
be terminated.                                                                  

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The Cap Counterparty will be obligated to make payments under the Yield 
Maintenance Agreement to the Trust, for the benefit of the Class A Certificates,
when LIBOR exceeds the related cap strike rate specified on Schedule 1 to this  
prospectus supplement for that Distribution Date, provided that such payment is 
limited when LIBOR exceeds 10.17%.                                              

   On each Distribution Date on which a Carryover Shortfall Amount is required
to be paid, the trustee will withdraw from funds available on deposit in the    
Certificate Account amounts to cover any Carryover Shortfall Amounts            
distributable to any of the Class A Certificates on such Distribution Date      
pursuant to the Yield Maintenance Agreement not in excess of amounts actually   
received from the Cap Counterparty for such Distribution Date and for such      
classes. See ' -- Priority of Distributions' in this prospectus supplement.     
There can be no assurance, however, that funds will be available to pay any such
Carryover Shortfall Amounts to holders of those Class A Certificates on such    
Distribution Date or subsequent Distribution Dates.                             

 Unless terminated earlier, the Yield Maintenance Agreement will terminate
after the Distribution Date in February 2014. Both the Trust and the Cap        
Counterparty will have the right to terminate the Yield Maintenance Agreement   
for certain reasons set forth in the documentation associated with the Yield    
Maintenance Agreement, including, without limitation, an ISDA Master Agreement, 
the Schedule thereto and a Confirmation thereunder. Although it is not          
anticipated that there will be amounts payable by the Trust, certain amounts may
be payable by the Trust to the Cap Counterparty under limited circumstances     
associated with the termination of the Yield Maintenance Agreement. Any such    
payment will be subordinate to the rights of the certificateholders.            

The Yield Maintenance Provider                                          

The Cap Counterparty is a bankruptcy remote derivatives product company 
based in New York, New York that has been established as a wholly owned         
subsidiary of The Bear Stearns Companies Inc. The Cap Counterparty has a ratings
classification of 'AAA' from S&P and 'Aaa' from Moody's. The Cap Counterparty   
will provide upon request, without charge, to each person to whom this          
prospectus supplement is delivered, a copy of (i) the ratings analysis from each
of S&P and Moody's evidencing those respective ratings or (ii) the most recent  
audited annual financial statements of the Cap Counterparty. Request for        
information should be directed to the DPC Manager of the Cap Counterparty at    
(212) 272-4009 or in writing at 383 Madison Avenue, 36th Floor, New York, New   
York 10179. The Cap Counterparty is an affiliate of Bear, Stearns & Co. Inc.    

CALCULATION OF LIBOR                                                            

    The annual certificate interest rates of the LIBOR Certificates are based on
the London Interbank Offered Rate for one-month United States dollar deposits   
('LIBOR') as determined by the servicer on the basis of quotations as described 
below. The servicer will determine LIBOR for each certificate accrual period on 
the second business day prior to the day on which that accrual period begins    
(each, a 'LIBOR DETERMINATION DATE'). For this purpose a 'business day' is any  
day on which banks in London and New York City are open for conducting          
transactions in foreign currency and exchange.                                  

    On each LIBOR Determination Date, the servicer will determine LIBOR based on
the 'Interest Settlement Rate' for United States dollar deposits of one-month   
maturity set by the British Bankers' Association (the 'BBA') as of 11:00 a.m.   
(London time) on such LIBOR Determination Date. Interest Settlement Rates       
currently are based on rates quoted by sixteen BBA designated banks as being, in
the view of such banks, the offered rate at which deposits are being quoted to  
prime banks in the London interbank market. Such Interest Settlement Rates are  
calculated by eliminating the four highest rates and the four lowest rates,     
averaging the eight remaining rates, carrying the result (expressed as a        
percentage) out to six decimal places, and rounding to five decimal places.     

  The BBA's Interest Settlement Rates are currently displayed on each of the
Dow Jones Telerate Service page 3750, Reuters Monitor Money Rates Service page  
'LIBOR01' and Bloomberg L.P. page 'BBAM' (each such page, or such other page as 
may replace any of the foregoing on such service or such other service as may be
nominated by the BBA as the information vendor for the purpose of               

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displaying the BBA's Interest Settlement Rates for deposits in United States    
dollars, each, a 'DESIGNATED TELERATE PAGE').                                   

  If on any LIBOR Determination Date, such Interest Settlement Rates are not
available from any Designated Telerate Page, LIBOR for the related accrual      
period will be the most recently published Interest Settlement Rate. In the     
event that the BBA no longer sets an Interest Settlement Rate, the servicer will
calculate LIBOR for the immediately following accrual period as follows: the    
servicer will determine LIBOR by reference to the quotations offered by the     
principal London office of each of the designated reference banks meeting the   
criteria set forth below for making one-month United States dollar deposits in  
leading banks in the London Interbank market, as of 11:00 a.m. (London time) on 
the LIBOR Determination Date.                                                   

 Under this method LIBOR will be established by the servicer on each LIBOR
Determination Date as follows:                                                  

  (a) If on any LIBOR Determination Date two or more reference banks
    provide offered quotations, LIBOR for the next interest accrual period shall
be the arithmetic mean of the offered quotations, carrying the result   
   (expressed as a percentage) out to six decimal places, and rounding to five
decimal places.                                                         

        (b) If on any LIBOR Determination Date only one or none of the reference
banks provides offered quotations, LIBOR for the next interest accrual  
period will be the greater of:                                          

      LIBOR as determined on the previous LIBOR Determination Date
or                                                    

the reserve interest rate.                            

The reserve interest rate will be the rate per annum that the servicer  
determines to be either:                                                        

      the arithmetic mean, (expressed as a percentage) carried out
    to six decimal places, and rounded to five decimal places,
      of the one-month United States dollar lending rates that New
      York City banks selected by the servicer are quoting, on the
    relevant LIBOR Determination Date, to the principal London
     offices of at least two of the reference banks to which the
  quotations are, in the opinion of the servicer, being so
made, or                                              

   if the servicer cannot determine the arithmetic mean, the
      lowest one-month United States dollar lending rate which New
     York City banks selected by the servicer are quoting on the
LIBOR Determination Date to leading European banks.   

      (c) If on any LIBOR Determination Date the servicer is required but is
unable to determine the reserve interest rate in the manner provided in 
paragraph (b) above, LIBOR for the next interest accrual period will be 
 LIBOR as determined on the preceding LIBOR Determination Date, or, in the
  case of the first LIBOR Determination Date, LIBOR will be considered to be
the per annum rate specified as such herein, if so specified.           

 Each reference bank (i) will be a leading bank engaged in transactions in
Eurodollar deposits in the international Eurocurrency market, (ii) will not     
control, be controlled by, or be under common control with, the servicer and    
(iii) will have an established place of business in London. If any reference    
bank should be unwilling or unable to act as such or if the servicer should     
terminate the designation of any such reference bank, the servicer will promptly
designate another leading bank meeting the criteria specified above.            

   The establishment of LIBOR on each LIBOR Determination Date by the servicer
for the related accrual period will, in the absence of manifest error, be final 
and binding.                                                                    

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DISTRIBUTIONS OF PRINCIPAL                                                      

GENERAL                                                                         

On each Distribution Date, certificateholders (other than holders of the
Class PPP Certificates) will be entitled to receive principal distributions from
the Available Distribution Amount to the extent and in the priority described in
this prospectus supplement. See ' -- Priority of Distributions' in this         
prospectus supplement. The Class PPP Certificates will not have a principal     
balance and will not receive any distributions of principal.                    

For any Distribution Date, the 'PRINCIPAL PAYMENT AMOUNT' is the sum of 
(i) the portion of the required monthly payments on the mortgage loans allocated
to principal after deducting accrued interest on the mortgage loans due on the  
Due Date immediately before the Distribution Date, (ii) the principal portion of
repurchase proceeds received with respect to any mortgage loan that was         
repurchased as required by the pooling agreement during the calendar month      
preceding the month of the Distribution Date and (iii) any other unscheduled    
payments of principal that were received on the mortgage loans during the       
preceding calendar month, other than Payoffs, Curtailments, Liquidation         
Principal or Subsequent Recoveries (each, as defined below).                    

   'PAYOFFS' are prepayments in full on a mortgage loan and 'CURTAILMENTS' are
partial prepayments on a mortgage loan, including any amounts in excess of the  
Minimum Monthly Payment. For any Distribution Date, the 'PRINCIPAL PREPAYMENT   
AMOUNT' is the sum of all Payoffs and Curtailments that were received during the
related Prepayment Period, reduced (but not to less than zero) by the aggregate 
amount of negative amortization with respect to the mortgage loans during the   
prior calendar month.                                                           

   For each Distribution Date and each Payoff, the related 'PREPAYMENT PERIOD'
will start on the 15th day of the month preceding the month in which the        
Distribution Date occurs (or, in the case of the first Distribution Date,       
beginning on the Cut-Off Date) and will end on the 14th day of the month in     
which the Distribution Date occurs. For each Distribution Date and each         
Curtailment, the related 'PREPAYMENT PERIOD' will be the month preceding the    
month in which the Distribution Date occurs.                                    

    'LIQUIDATION PRINCIPAL' is the principal portion of Liquidation Proceeds (as
defined in the pooling agreement) received with respect to each mortgage loan   
that became a Liquidated Mortgage Loan (as defined below) (but not in excess of 
the principal balance of that mortgage loan) during the calendar month preceding
the month of the Distribution Date. A 'LIQUIDATED MORTGAGE LOAN' is a mortgage  
loan for which the servicer has determined that it has received all amounts that
it expects to recover from or on account of the mortgage loan, whether from     
Insurance Proceeds (as defined in the pooling agreement), Liquidation Proceeds  
or otherwise.                                                                   

Distributions to certificateholders (other than the holders of the      
Class PPP Certificates) on each Distribution Date will include any Subsequent   
Recoveries received by the servicer during the calendar month preceding the     
month of the Distribution Date. 'SUBSEQUENT RECOVERIES' are amounts received by 
the servicer in connection with the liquidation of defaulted mortgage loans     
after those mortgage loans became Liquidated Mortgage Loans, up to the amount of
losses previously allocated in respect of those mortgage loans. On each         
Distribution Date on which Subsequent Recoveries are distributed to             
certificateholders, the Class Principal Balance of the class of Subordinate     
Certificates with the lowest priority outstanding generally will be increased by
the amount of those Subsequent Recoveries.                                      

  The Class X Certificates will only be entitled to receive distributions of
principal to the extent of the Class X Principal Balance. The Class X           
Certificates will not receive principal distributions on the Class X Notional   
Amount. See ' -- Distributions of Interest -- Class X Notional Amount and       
Class X Principal Balance' in this prospectus supplement.                       

SENIOR PRINCIPAL DISTRIBUTION AMOUNT                                            

On each Distribution Date before the Credit Support Depletion Date, an  
amount, up to the amount of the Senior Principal Distribution Amount (as defined
below) for that Distribution Date, will be distributed as principal,            
sequentially, as follows:                                                       

        (i) first, to the Class A Certificates, concurrently, pro rata according
 to the Class Principal Balance (or with respect to clauses (B) and (D) of
this paragraph, the respective aggregate                                

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Class Principal Balance) of the certificates described in each of       
clause (A), (B), (C), (D) and (E), as follows:                          

        (A) to the Class A-1A Certificates, until the Class A-1A Principal
Balance has been reduced to zero;                                 

           (B) to the Class A-1B1 and Class A-1B2 Certificates; sequentially, as
follows:                                                          

   (1) first, to the Class A-1B1 Certificates, until the
 Class A-1B1 Principal Balance has been reduced to zero; and

    (2) second, to the Class A-1B2 Certificates, until the
 Class A-1B2 Principal Balance has been reduced to zero; and

          (C) to the Class A-1B3 Certificates, until the Class A-1B3 Principal
Balance has been reduced to zero;                                 

       (D) to the Class A-1C1, Class A-1C2 and Class A-1C3 Certificates;
sequentially, as follows:                                         

   (1) first, to the Class A-1C1 Certificates, until the
Class A-1C1 Principal Balance has been reduced to zero;   

    (2) second, to the Class A-1C2 Certificates, until the
 Class A-1C2 Principal Balance has been reduced to zero; and

   (3) third, to the Class A-1C3 Certificates, until the
 Class A-1C3 Principal Balance has been reduced to zero; and

          (E) to the Class A-1C4 Certificates, until the Class A-1C4 Principal
Balance has been reduced to zero; and                             

       (ii) second, to the Class X principal-only component, until the Class X
principal-only component has been reduced to zero.                      

 The 'SENIOR PRINCIPAL DISTRIBUTION AMOUNT' for any Distribution Date will
equal the sum of (i) the Senior Percentage (as defined below) of the Principal  
Payment Amount, (ii) the Senior Prepayment Percentage (as defined under         
' -- Principal Prepayments' in this prospectus supplement) of the Principal     
Prepayment Amount and (iii) the Senior Liquidation Amount (as defined below);   
provided, however, that for the first Distribution Date, this amount will be    
reduced by $100 to pay principal to the Class R Certificates as provided in     
clause (ii) of the first paragraph under ' -- Priority of Distributions' in this
prospectus supplement.                                                          

  The 'SENIOR PERCENTAGE' for any Distribution Date will equal the aggregate
Class Principal Balance of the Class A and Class R Certificates and the Class X 
principal-only component divided by the aggregate Class Principal Balance of the
Class A, Class X, Class R and Class B Certificates, in each case immediately    
before that Distribution Date. The 'SUBORDINATE PERCENTAGE' for any Distribution
Date will equal the excess of 100% over the Senior Percentage for that date. The
Senior Percentage and the Subordinate Percentage as of the Closing Date will be 
approximately 90.75% and 9.25%, respectively.                                   

    The 'SENIOR LIQUIDATION AMOUNT' for any Distribution Date will equal the sum
of (A) the aggregate, for each mortgage loan that became a Liquidated Mortgage  
Loan during the calendar month preceding the month of that Distribution Date, of
the lesser of (i) the Senior Percentage of the Stated Principal Balance of that 
mortgage loan and (ii) the Senior Prepayment Percentage of the Liquidation      
Principal with respect to that mortgage loan and (B) the Senior Prepayment      
Percentage of any Subsequent Recoveries.                                        

The 'STATED PRINCIPAL BALANCE' of any mortgage loan as of any date of   
determination is equal to its principal balance as of the Cut-Off Date, after   
application of all scheduled principal payments due on or before the Cut-Off    
Date, whether or not received, reduced by all amounts allocable to principal    
that have been distributed to certificateholders with respect to that mortgage  
loan on or before that date of determination, and as further reduced to the     
extent that any realized loss on that mortgage loan has been allocated to one or
more classes of certificates on or before that date of determination, and as    
increased by the amounts of any negative amortization (as described above under 
'Description of the Mortgage Pool') with respect to that mortgage loan for all  
prior interest accrual periods.                                                 

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SUBORDINATE PRINCIPAL DISTRIBUTION AMOUNT                                       

 On each Distribution Date, an amount, up to the amount of the Subordinate
Principal Distribution Amount for that Distribution Date, will be distributed as
principal to the Subordinate Certificates. On each Distribution Date, except    
Distribution Dates on which the Subordination Level for any class or classes of 
the Subordinate Certificates is less than the related Subordination Level as of 
the Closing Date, each class of the Subordinate Certificates will be entitled to
receive its pro rata (by Class Principal Balance) share of the Subordinate      
Principal Distribution Amount, to the extent of the Available Distribution      
Amount remaining after distributions of interest and principal to the Senior    
Certificates, distributions of interest and principal to all of the Subordinate 
Certificates senior to that class and distributions of interest to that class.  
See ' -- Priority of Distributions' in this prospectus supplement. The relative 
seniority, from highest to lowest, of the Subordinate Certificates is as        
follows: Class B-1, Class B-2, Class B-3, Class B-4, Class B-5, Class B-6,      
Class B-7, Class B-8, Class B-9, Class B-10, Class B-11, Class B-12 and         
Class B-13.                                                                     

 The 'SUBORDINATE PRINCIPAL DISTRIBUTION AMOUNT' for any Distribution Date
will equal the sum of (i) the Subordinate Percentage of the Principal Payment   
Amount; (ii) the Subordinate Principal Prepayments Distribution Amount (as      
defined below); and (iii) the Subordinate Liquidation Amount (as defined below).

The 'SUBORDINATE PRINCIPAL PREPAYMENTS DISTRIBUTION AMOUNT' for any     
Distribution Date will equal the Subordinate Prepayment Percentage of the       
Principal Prepayment Amount.                                                    

    The 'SUBORDINATE PREPAYMENT PERCENTAGE' for any Distribution Date will equal
the excess of 100% over the Senior Prepayment Percentage; provided, however,    
that if the aggregate Class Principal Balance of the Class A and Class R        
Certificates and the Class X principal-only component has been reduced to zero, 
then the Subordinate Prepayment Percentage will equal 100%.                     

 The 'SUBORDINATE LIQUIDATION AMOUNT' for any Distribution Date will equal
the excess, if any, of the sum of (i) the aggregate Liquidation Principal for   
all mortgage loans that became Liquidated Mortgage Loans during the calendar    
month preceding the month of that Distribution Date and (ii) any Subsequent     
Recoveries received during that calendar month, over the Senior Liquidation     
Amount for that Distribution Date.                                              

The rights of the holders of the Class B Certificates to receive        
distributions of interest and principal are subordinated to the rights of the   
holders of the Senior Certificates to receive all distributions of interest and 
principal to which they are entitled. See ' -- Subordination and Allocation of  
Losses' in this prospectus supplement.                                          

PRINCIPAL PREPAYMENTS                                                           

The 'SENIOR PREPAYMENT PERCENTAGE' for any Distribution Date before     
September 2015 will equal 100%. During the next four years, this percentage will
be calculated as follows:                                                       

     for any Distribution Date occurring in or between September
2015 and August 2016, the Senior Percentage for that  
      Distribution Date plus 70% of the Subordinate Percentage for
that Distribution Date;                               

     for any Distribution Date occurring in or between September
2016 and August 2017, the Senior Percentage for that  
      Distribution Date plus 60% of the Subordinate Percentage for
that Distribution Date;                               

     for any Distribution Date occurring in or between September
2017 and August 2018, the Senior Percentage for that  
      Distribution Date plus 40% of the Subordinate Percentage for
that Distribution Date; and                           

     for any Distribution Date occurring in or between September
2018 and August 2019, the Senior Percentage for that  
      Distribution Date plus 20% of the Subordinate Percentage for
that Distribution Date.                               

For any Distribution Date occurring in or after September 2019, the Senior      
Prepayment Percentage will equal the Senior Percentage for that Distribution    
Date.                                                                           

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   There are important exceptions to the calculations of the Senior Prepayment
Percentage described in the above paragraph. On any Distribution Date, (i) if   
the Senior Percentage for that Distribution Date exceeds the initial Senior     
Percentage as of the Closing Date, then the Senior Prepayment Percentage for    
that Distribution Date will equal 100%, (ii) if on or before the Distribution   
Date in August 2008, the Subordinate Percentage for that Distribution Date is   
greater than or equal to twice that percentage as of the Closing Date, then the 
Senior Prepayment Percentage for that Distribution Date will equal the Senior   
Percentage plus 50% of the Subordinate Percentage for that Distribution Date,   
and (iii) if after the Distribution Date in August 2008, the Subordinate        
Percentage for that Distribution Date is greater than or equal to twice that    
percentage as of the Closing Date, then the Senior Prepayment Percentage for    
that Distribution Date will equal the Senior Percentage.                        

    Notwithstanding the above, on any Distribution Date, if the delinquencies or
losses on the mortgage loans exceed the limits specified in the pooling         
agreement, then the Senior Prepayment Percentage for that Distribution Date will
not decrease as described in the definition of Senior Prepayment Percentage in  
the above two paragraphs. Finally, if on any Distribution Date the allocation to
the Senior Certificates in the percentage required would reduce the aggregate   
Class Principal Balance of those certificates below zero, the Senior Prepayment 
Percentage for that Distribution Date will be limited to the percentage         
necessary to reduce that Class Principal Balance to zero.                       

SUBORDINATION AND ALLOCATION OF LOSSES                                          

The Subordinate Certificates will be subordinate in right of payment and
provide credit support to the Senior Certificates to the extent described in    
this prospectus supplement. The support provided by the Subordinate Certificates
is intended to enhance the likelihood of regular receipt by the Senior          
Certificates of the full amount of the monthly distributions of interest and    
principal to which they are entitled and to afford the Senior Certificates      
protection against some losses. The protection afforded to the Senior           
Certificates by the Subordinate Certificates will be accomplished by the        
preferential right on each Distribution Date of the Senior Certificates to      
receive distributions of interest and principal to which they are entitled      
before distributions of interest and principal to the Subordinate Certificates  
and by the allocation of losses to the Subordinate Certificates before any      
allocation of losses to the Senior Certificates.                                

  In addition, each class of Subordinate Certificates will be subordinate in
right of payment and provide credit support to each class of Subordinate        
Certificates with a lower numerical class designation. The protection afforded a
class of Subordinate Certificates by the classes of Subordinate Certificates    
with higher numerical class designations will be similarly accomplished by the  
preferential right of those classes with lower numerical class designations to  
receive distributions of interest and principal before distributions of interest
and principal to those classes of Subordinate Certificates with higher numerical
class designations.                                                             

 After the Class Principal Balances of all of the Subordinate Certificates
have been reduced to zero, any loss with respect to a mortgage loan will be     
allocated to the Class A Certificates and the Class X principal-only component, 
pro rata, until their respective class principal or component, as applicable,   
balances have been reduced to zero; provided, however, that any loss that would 
otherwise be allocated to the Class A-1A Certificates will be allocated         
(i) first, to the Class A-1C1, Class A-1C2, Class A-1C3 and Class A-1C4         
Certificates, pro rata based on Class Principal Balance, until their respective 
Class Principal Balances have each been reduced to zero and (ii) second, to the 
Class A-1B1, Class A-1B2 and Class A-1B3 Certificates, pro rata based on        
Class Principal Balance, until their respective Class Principal Balances have   
each been reduced to zero; and provided, further, that any loss that would      
otherwise be allocated to the Class A-1B1, Class A-1B2 or Class A-1B3           
Certificates will be allocated to the Class A-1C1, Class A-1C2, Class A-1C3 and 
Class A-1C4 Certificates, pro rata based on Class Principal Balance, until their
respective Class Principal Balances have each been reduced to zero.             

Any loss realized on a mortgage loan will be allocated among the        
certificates as follows:                                                        

(i) for losses allocable to principal:                          

  (a) first, to the Junior Subordinate Certificates in reverse
     numerical order, until their aggregate Class Principal Balance has been
reduced to zero;                                                  

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    (b) second, to the Class B-9 Certificates, until the Class B-9
Principal Balance has been reduced to zero;                       

   (c) third, to the Class B-8 Certificates, until the Class B-8
Principal Balance has been reduced to zero;                       

    (d) fourth, to the Class B-7 Certificates, until the Class B-7
Principal Balance has been reduced to zero;                       

   (e) fifth, to the Class B-6 Certificates, until the Class B-6
Principal Balance has been reduced to zero;                       

   (f) sixth, to the Class B-5 Certificates, until the Class B-5
Principal Balance has been reduced to zero;                       

     (g) seventh, to the Class B-4 Certificates, until the Class B-4
Principal Balance has been reduced to zero;                       

    (h) eighth, to the Class B-3 Certificates, until the Class B-3
Principal Balance has been reduced to zero;                       

   (i) ninth, to the Class B-2 Certificates, until the Class B-2
Principal Balance has been reduced to zero;                       

   (j) tenth, to the Class B-1 Certificates, until the Class B-1
Principal Balance has been reduced to zero; and                   

(k) eleventh, to the Class A Certificates and the Class X 
       principal-only component, pro rata according to, and in reduction of, the
Class Principal Balances and principal-only component balance,    
respectively, thereof;                                            

and                                                                             

(ii) for losses allocable to interest:                          

  (a) first, to the Junior Subordinate Certificates in reverse
      numerical order, in reduction of accrued but unpaid interest and then in
reduction of the Class Principal Balances of those certificates;  

        (b) second, to the Class B-9 Certificates, in reduction of accrued
  but unpaid interest and then in reduction of the Class B-9 Principal
Balance;                                                          

           (c) third, to the Class B-8 Certificates, in reduction of accrued but
       unpaid interest and then in reduction of the Class B-8 Principal Balance;

        (d) fourth, to the Class B-7 Certificates, in reduction of accrued
  but unpaid interest and then in reduction of the Class B-7 Principal
Balance;                                                          

           (e) fifth, to the Class B-6 Certificates, in reduction of accrued but
       unpaid interest and then in reduction of the Class B-6 Principal Balance;

           (f) sixth, to the Class B-5 Certificates, in reduction of accrued but
       unpaid interest and then in reduction of the Class B-5 Principal Balance;

         (g) seventh, to the Class B-4 Certificates, in reduction of accrued
  but unpaid interest and then in reduction of the Class B-4 Principal
Balance;                                                          

        (h) eighth, to the Class B-3 Certificates, in reduction of accrued
  but unpaid interest and then in reduction of the Class B-3 Principal
Balance;                                                          

           (i) ninth, to the Class B-2 Certificates, in reduction of accrued but
       unpaid interest and then in reduction of the Class B-2 Principal Balance;

           (j) tenth, to the Class B-1 Certificates, in reduction of accrued but
       unpaid interest and then in reduction of the Class B-1 Principal Balance;
and                                                               

     (k) eleventh, to the Class A and Class X Certificates, pro rata
     according to, and in reduction of, accrued but unpaid interest on those
      classes, and then to the Class A Certificates and Class X principal-only
component, pro rata according to, and in reduction of, the        
Class Principal Balances and principal-only component balance,    
respectively, thereof;                                            

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provided, however, that losses allocated to principal and interest that would be
allocable to the Class A-1A Certificates will be allocated (i) first, to the    
Class A-1C1, Class A-1C2, Class A-1C3 and Class A-1C4 Certificates, pro rata    
based on Class Principal Balance, until their respective Class Principal        
Balances have each been reduced to zero and (ii) second, to the Class A-1B1,    
Class A-1B2 and Class A-1B3 Certificates, pro rata based on Class Principal     
Balance, until their respective Class Principal Balances have each been reduced 
to zero; and provided, further, that any loss that would otherwise be allocated 
to the Class A-1B1, Class A-1B2 or Class A-1B3 Certificates will be allocated to
the Class A-1C1, Class A-1C2, Class A-1C3 and Class A-1C4 Certificates, pro rata
based on Class Principal Balance, until their respective Class Principal        
Balances have each been reduced to zero.                                        

  On each Distribution Date, if the aggregate Class Principal Balance of all
outstanding classes of certificates exceeds the aggregate Stated Principal      
Balance of the mortgage loans (after giving effect to distributions of principal
and the allocation of all losses to the certificates on that Distribution Date),
that excess will be deemed a principal loss and will be allocated to the most   
junior class of Subordinate Certificates then outstanding.                      

THE CLASS R CERTIFICATES                                                        

The Class R Certificates will receive $100 of principal on the first    
Distribution Date, as well as one month's interest on that amount. These        
certificates will not receive any distributions of interest or principal on any 
other Distribution Date. However, on each Distribution Date, the Class R        
Certificates will receive any amounts remaining (which are not expected to be   
material) in the Certificate Account from the Available Distribution Amount     
after distributions of interest and principal on the regular interests issued by
REMIC II (as defined in the pooling agreement) and payment of expenses, if any, 
of the Trust, together with excess liquidation proceeds (as described in        
paragraph (1)(g) of ' -- Available Distribution Amount' below), if any.         
Distributions of any remaining amounts to the Class R Certificates will be      
subordinate to all payments required to be made with respect to the other       
certificates and each class of REMIC I Regular Interests (as defined in the     
pooling agreement) on any Distribution Date.                                    

ADVANCES                                                                        

For each mortgage loan, the servicer will make advances for each        
Distribution Date to cover any shortfall between (i) Minimum Monthly Payments   
scheduled to be received for that mortgage loan and (ii) the amounts actually   
received. However, if the servicer determines, in good faith, that an advance   
would not be recoverable from insurance proceeds, liquidation proceeds or other 
amounts received for the mortgage loan, it will not make an advance. If, at the 
time a mortgage loan becomes a Liquidated Mortgage Loan, an advance previously  
made by the servicer with respect to that mortgage loan has not been recovered  
from late payments, insurance proceeds, liquidation proceeds or other amounts   
received for that mortgage loan, the servicer will be entitled to be reimbursed 
for such advance from collections on other mortgage loans owned by the Trust.   

AVAILABLE DISTRIBUTION AMOUNT                                                   

On each Distribution Date, the Available Distribution Amount for that   
Distribution Date, which will generally include scheduled principal and interest
payments due on the Due Date immediately before that Distribution Date,         
Curtailments received in the previous calendar month (as described below),      
Payoffs received in the Prepayment Period to the extent described below and     
amounts received from liquidations of mortgage loans in the previous calendar   
month, will be distributed to the certificateholders, as specified in this      
prospectus supplement.                                                          

    The 'AVAILABLE DISTRIBUTION AMOUNT' for any Distribution Date, as more fully
described in the pooling agreement, will equal the sum of the following amounts:

(1) the total amount of all cash received by or on behalf of the
   servicer for the mortgage loans by the determination date (which will be at
    least ten days before that Distribution Date) and not previously distributed
 (including advances made by the servicer, proceeds of mortgage loans that
are liquidated and scheduled amounts of distributions from buydown funds
respecting buydown loans, if any), except:                              

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        (a) all scheduled payments of principal and interest collected but
due on a date after that Distribution Date;                       

      (b) all Curtailments received after the previous calendar month;

      (c) all Payoffs received after the Prepayment Period immediately
  preceding that Distribution Date (together with any interest payment
      received with those Payoffs to the extent that it represents the payment
of interest accrued on the mortgage loans for the period after the
     previous calendar month), and interest that was accrued and received on
      Payoffs received during the period from the first to the 14th day of the
     month of that Distribution Date, which interest will not be included in
       the calculation of the Available Distribution Amount for any Distribution
Date;                                                             

 (d) Liquidation Proceeds, Insurance Proceeds and Subsequent
   Recoveries received on the mortgage loans after the previous calendar
month;                                                            

         (e) all amounts that are due and reimbursable to the servicer under
the pooling agreement;                                            

(f) the servicing fee for each mortgage loan; and         

          (g) excess liquidation proceeds, which equals the excess, if any, of
  aggregate Liquidation Proceeds on mortgage loans received during the
      previous calendar month over the amount that would have been received if
   Payoffs had been made with respect to the mortgage loans on the dates
those Liquidation Proceeds were received;                         

(2) the total, to the extent not previously distributed, of the 
    following amounts, to the extent advanced or received, as applicable, by the
servicer:                                                               

      (a) all advances made by the servicer for that Distribution Date
relating to mortgage loans; and                                   

         (b) any amounts payable as Compensating Interest by the servicer on
that Distribution Date; and                                       

   (3) the total amount of any cash received during the calendar month
  before that Distribution Date by the trustee or the servicer in respect of
   the obligation of Washington Mutual Mortgage Securities Corp. to repurchase
any mortgage loans.                                                     

LAST SCHEDULED DISTRIBUTION DATE                                                

The Last Scheduled Distribution Date for the certificates is the        
Distribution Date in August 2045, which is the Distribution Date in the month   
after the scheduled maturity date for the latest maturing mortgage loan.        

    The actual rate of principal payments on the certificates will depend on the
rate of principal payments (including principal prepayments) on the mortgage    
loans, which, in turn, may be influenced by a variety of economic, geographic   
and social factors, as well as the level of prevailing mortgage interest rates. 
No assurance can be given as to the actual payment experience on the mortgage   
loans.                                                                          

OPTIONAL TERMINATION OF THE TRUST                                               

  On any Distribution Date after the Clean-Up Call Option Date, the servicer
may purchase the mortgage loans and all property acquired in respect of any     
mortgage loan still owned by the Trust, which will cause the termination of the 
Trust and the retirement of the certificates. The purchase price will equal,    
after deduction of related advances by the servicer, the sum of (1) 100% of the 
aggregate outstanding principal balance of the mortgage loans (other than       
Liquidated Mortgage Loans), plus accrued interest at the applicable Pass-Through
Rates through the last day of the month of purchase, less any Bankruptcy Losses 
realized with respect to the mortgage loans not already allocated to the        
certificates and (2) the fair market value of all property acquired in respect  
of any mortgage loan still owned by the Trust.                                  

 An optional termination of the Trust will cause the outstanding principal
balance of the certificates to be paid in full through the distribution of the  
proceeds of that purchase and the allocation of the                             

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associated realized losses, if any, on each mortgaged property owned by the     
Trust the fair market value of which is less than the principal balance of the  
related mortgage loan as of the time that the Trust acquired the mortgaged      
property and accrued and unpaid interest on that mortgage loan, and upon that   
payment in full, the Trust will be terminated. In no event will the Trust       
continue beyond the expiration of 21 years from the death of the survivor of the
persons identified in the pooling agreement. See 'Description of Certificates --
Termination' in the prospectus.                                                 

SERVICING COMPENSATION AND PAYMENT OF EXPENSES                                  

The servicer will receive a fee for its services as servicer under the  
pooling agreement. The servicing fee is calculated as a per annum percentage for
each mortgage loan. The servicing fee with respect to each mortgage loan will   
equal 0.375%. Any prepayment penalty payment remitted to the Trust with respect 
to voluntary full prepayments on a mortgage loan will be distributed to the     
holders of the Class PPP Certificates. The holders of the Class PPP Certificates
will not receive any prepayment penalty payment remitted to the Trust with      
respect to voluntary partial prepayments; each such payment will be retained by 
the servicer as additional servicing compensation. No prepayment penalty        
payments will be available for distribution to holders of the other classes of  
certificates.                                                                   

Washington Mutual Bank, as servicer, will pay all expenses incurred in  
connection with its responsibilities under the pooling agreement (subject to    
reimbursement as described in the prospectus or this prospectus supplement for  
specified expenses such as those incurred by it in connection with the          
liquidation of defaulted mortgage loans and the restoration of damaged mortgaged
properties), including, without limitation, the various items of expense        
described in the prospectus. In particular, each month or year, as applicable,  
the servicer will be obligated to pay from the servicing fee the fees of the    
trustee and specified other fees and expenses of the Trust, as prescribed by the
pooling agreement.                                                              

SPECIAL SERVICING AGREEMENTS                                                    

    The pooling agreement permits the servicer to enter into one or more special
servicing agreements with unaffiliated owners of one or more classes of         
Subordinate Certificates or of a class of securities representing interests in  
one or more classes of Subordinate Certificates. Under those agreements, the    
owner may, for delinquent mortgage loans:                                       

    (a) instruct the servicer to start or delay foreclosure proceedings,
provided that the owner deposits a specified amount of cash with the    
   servicer, which will be available for distribution to certificateholders if
Liquidation Proceeds are less than they otherwise may have been had the 
servicer acted pursuant to its normal servicing procedures;             

       (b) purchase those delinquent mortgage loans from the Trust immediately
before the beginning of foreclosure proceedings at a price equal to the 
   aggregate outstanding principal balance of the mortgage loans, plus accrued
  interest at the applicable mortgage interest rates through the last day of
the month in which the mortgage loans are purchased; and/or             

(c) assume all of the servicing rights and obligations for the  
delinquent mortgage loans so long as (i) the servicer has the right to  
transfer the servicing rights and obligations of the mortgage loans to  
another servicer and (ii) the owner will service the mortgage loans     
according to Washington Mutual Bank's servicing guidelines.             

REPORTS TO CERTIFICATEHOLDERS                                                   

  The trustee may make available any reports required to be delivered by the
trustee pursuant to the pooling agreement and certain other information through 
its internet website. The web page is currently located at                      
'https://www.tss.db.com/invr.' Assistance in using the website can be obtained  
by calling the trustee's investor relations desk at 800-735-7777. Parties that  
are unable to use the above distribution method are entitled to have a paper    
copy mailed to them via first class mail by calling the investor relations desk 
and requesting a paper copy. The servicer may make available any reports        
required to be delivered by it or an affiliate of Washington Mutual Mortgage    
Securities Corp. pursuant to the prospectus or the pooling agreement and other  
information through a web page on the world wide web. The web page is located at
'www.wamumsc.com' and reports are available by clicking on 'Investor            
Information.'                                                                   

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DELINQUENCY, LOSS AND FORECLOSURE EXPERIENCE

   The following table contains certain information, as reported to Washington
Mutual Mortgage Securities Corp., by its various servicers, including Washington
Mutual Bank, concerning recent delinquency, loss and foreclosure experience on  
mortgage loans included in various mortgage pools underlying all series of      
Washington Mutual Mortgage Securities Corp.'s mortgage pass-through certificates
in which one or more classes of certificates were publicly offered.             

There can be no assurance that the delinquency, loss and foreclosure    
experience shown in the following table (which includes mortgage loans with     
various terms to stated maturity and a variety of payment characteristics, such 
as balloon loans and buydown loans) will be representative of the results that  
may be experienced for the mortgage loans owned by the Trust. Delinquencies,    
losses and foreclosures generally are expected to occur more frequently after   
the first full year of the life of a mortgage loan. Accordingly, because a large
number of mortgage loans included in the mortgage pools underlying Washington   
Mutual Mortgage Securities Corp.'s mortgage pass-through certificates have been 
recently originated, the current level of delinquencies, losses and foreclosures
may not be representative of the levels that may be experienced over the lives  
of those mortgage loans.                                                        

                                                        [Enlarge/Download Table]

                            AT OR FOR THE YEAR ENDED   AT OR FOR THE YEAR ENDED   AT OR FOR THE SIX MONTHS 
                                DECEMBER 31, 2003          DECEMBER 31, 2004         ENDED JUNE 30, 2005   
                            -------------------------  -------------------------  -------------------------
                                          BY DOLLAR                  BY DOLLAR                  BY DOLLAR  
                                          AMOUNT OF                  AMOUNT OF                  AMOUNT OF  
                            BY NO. OF       LOANS      BY NO. OF       LOANS      BY NO. OF       LOANS    
                              LOANS     (IN MILLIONS)    LOANS     (IN MILLIONS)    LOANS     (IN MILLIONS)
                              -----     -------------    -----     -------------    -----     -------------
                                                                                                           
Total Rated Mortgage Pass-                                                                                 
  Through Certificate                                                                                      
  Portfolio................    97,493     $42,868.4       96,726     $40,900.9      119,030     $50,408.0  
Average Balance(1).........   109,032      46,309.2       90,475      39,459.2      110,544      48,130.0  
Period of Delinquency(2)                                                                                   
    31 to 59 days..........     1,632         477.7        1,064         309.4        1,289         415.3  
    60 to 89 days..........       336          81.8          198          40.0          206          52.5  
    90 days or more........       294          68.9          155          36.9           83          21.9  
                            ---------     ---------    ---------     ---------    ---------     ---------  
Total Delinquent Loans.....     2,262     $   628.4        1,417     $   386.3        1,578     $   489.7  
Delinquency Rate...........      2.32%         1.47%        1.46%         0.94%        1.33%         0.97% 
Foreclosures(3)............       813     $   151.8          433     $    84.4          220     $    53.6  
Foreclosure Ratio(4).......      0.83%         0.35%        0.45%         0.21%        0.18%         0.11% 
Covered Losses(5)..........               $    16.4                  $    10.6                  $     1.8  
Applied Losses(6)..........               $    15.0                  $    10.0                  $     1.8  

Note: Due to rounding, totals may not equal sum of line items.                  
---------                                                                       

(1) Average balance for the period indicated is based on end of month balances  
divided by the number of months in the period indicated.                

(2) The indicated periods of delinquency are based on the number of days past   
   due, based on a 30-day month. No mortgage loan is considered delinquent for
  the purpose of this table until one month has passed after the related due
 date. A mortgage loan is no longer considered delinquent once foreclosure
proceedings have begun.                                                 

(3) Includes mortgage loans for which foreclosure proceedings had been          
instituted or for which the related property had been acquired as of the
dates indicated.                                                        

(4) Foreclosures as a percentage of total mortgage loans at the end of each     
period.                                                                 

(5) Covered losses are gross losses (as defined below) realized during the      
period indicated that were covered by credit enhancements obtained or   
established for one or more pools of mortgage loans, exclusive of any   
   insurance (such as primary mortgage insurance or ordinary hazard insurance)
that was available for specific mortgage loans or mortgaged properties. 
'Gross losses' are the sum for each mortgage loan liquidated during the 
  applicable period of the difference between (a) the sum of the outstanding
principal balance plus accrued interest, plus all liquidation expenses  
    related to the mortgage loan and (b) all amounts received in connection with
    the liquidation of the related mortgaged property, including insurance (such
    as primary mortgage insurance or ordinary hazard insurance) available solely
for the mortgage loan or the related mortgaged property.                

(6) Applied losses are covered losses that were applied against the outstanding 
principal balance of the mortgage pass-through certificates during the  
period indicated.                                                       

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YIELD AND PREPAYMENT CONSIDERATIONS 

GENERAL                                                                         

   The yield to maturity of each class of certificates will depend upon, among
other things, the price at which the certificates are purchased, the amount     
payable to that class as interest, the actual characteristics of the mortgage   
loans, the rate of principal payments (including prepayments) on the mortgage   
loans and the rate and timing of liquidations and loss severity on the mortgage 
loans. The yield to maturity to holders of the Class X Certificates will be     
lower than the yield to maturity otherwise produced by the applicable interest  
rate and purchase price of those certificates because interest and principal    
distributions will not be payable to the certificateholders until the 25th day  
of the month following the month of accrual (without any additional distribution
of interest or earnings with respect to the delay).                             

The mortgage interest rates on the mortgage loans will adjust monthly   
(except during an initial fixed-rate period for some of the mortgage loans of   
one, two, three or twelve months) and may vary significantly over time. When a  
mortgage loan begins its adjustable period, increases and decreases in the      
mortgage interest rate on that mortgage loan will be calculated for each monthly
accrual period based on the index as of a specified date. The index may not rise
and fall consistently with mortgage interest rates. As a result, the mortgage   
interest rates on the mortgage loans at any time may not equal the prevailing   
mortgage interest rates for similar adjustable-rate loans, and accordingly the  
prepayment rate may be lower or higher than would otherwise be anticipated.     
Moreover, each mortgage loan has a Rate Ceiling.                                

Although mortgage interest rates will increase (subject to the Rate     
Ceilings) or decrease as the index changes (following the initial fixed-rate    
period, if applicable), the Minimum Monthly Payments on the mortgage loans      
generally will adjust only once a year. As a result, an increase or decrease in 
the index will cause the amortization of the mortgage loans to decelerate or    
accelerate, thereby causing a corresponding change in the amortization of the   
certificates. In the event that an increase in the index causes the interest due
on a mortgage loan for a given month to exceed the current monthly payment for  
that month, the shortfall in interest will be added to the outstanding principal
balance of that mortgage loan in the form of 'negative amortization.' In        
addition, because the initial Minimum Monthly Payment is set based on the       
initial fixed rate rather than the sum of the Margin and then-current Index, it 
is likely that the Minimum Monthly Payment will be less than the interest due on
that mortgage loan during the early years of a mortgage loan. If a mortgagor    
only pays the Minimum Monthly Payment due, there will likely be interest        
shortfalls and the corresponding negative amortization on the mortgage loan     
until the fifth anniversary of the Due Date when the Minimum Monthly Payment    
will be reset to a fully amortizing amount.                                     

 Amounts received with respect to Payoffs and Curtailments will be used to
cover interest shortfalls resulting from negative amortization. To the extent   
that the aggregate amount of negative amortization with respect to all mortgage 
loans for a given month exceeds the amount of Payoffs and Curtailments for the  
related Distribution Date, such excess amount will be deducted from the interest
payable to the certificates and added to the Class Principal Balances of the    
certificates as described in 'Description of the Certificates -- Distributions  
of Interest,' thereby causing a delay in the payment of accrued interest.       
See 'Description of the Mortgage Pool' in this prospectus supplement.           

    In the event that interest accrued on the Class X Notional Amount is reduced
as a result of Net Negative Amortization, such amount will be added as principal
to the outstanding component principal balance of the Class X principal-only    
component. Before the Credit Support Depletion Date, the Class X Certificates   
will not receive any distributions of principal until the Class Principal       
Balances of the Class A Certificates have all been reduced to zero.             

Further, some mortgagors who prefer the certainty provided by fixed-rate
mortgage loans may nevertheless obtain adjustable-rate mortgage loans at a time 
when they regard the mortgage interest rates (and, therefore, the payments) on  
fixed-rate mortgage loans as unacceptably high. These mortgagors may be induced 
to refinance adjustable-rate mortgage loans when the mortgage interest rates and
monthly payments on comparable fixed-rate mortgage loans decline to levels that 
these mortgagors regard as acceptable, even though the mortgage interest rates  
and monthly payments may be significantly higher than the current mortgage      
interest rates and monthly payments on the mortgagors' adjustable-rate mortgage 
loans. The ability to refinance a mortgage loan will depend on a number of      
factors prevailing at the time                                                  

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refinancing is desired, including, without limitation, real estate values, the  
mortgagor's financial situation, prevailing mortgage interest rates, the        
mortgagor's equity in the related mortgaged property, tax laws and prevailing   
general economic conditions.                                                    

PRINCIPAL PREPAYMENTS AND COMPENSATING INTEREST                                 

  When a mortgagor prepays a mortgage loan in full between Due Dates for the
mortgage loan, the mortgagor pays interest on the amount prepaid only to the    
date of prepayment instead of for the entire month. Also, when a Curtailment is 
made on a mortgage loan together with the scheduled Minimum Monthly Payment for 
a month on or after the related Due Date, the principal balance of the mortgage 
loan is reduced by the amount of the Curtailment as of that Due Date, but the   
principal is not distributed to certificateholders until the Distribution Date  
in the next month; therefore, one month of interest shortfall accrues on the    
amount of the Curtailment.                                                      

 To reduce the adverse effect on certificateholders from the deficiency in
interest payable as a result of a Payoff on a mortgage loan between its Due     
Dates, the servicer will pass through Compensating Interest to the              
certificateholders to the limited extent and in the manner described below. The 
servicer is obligated to remit to the Certificate Account on the day before each
Distribution Date with respect to the mortgage loans that experience a Payoff   
between the 15th day and the last day of the month before the Distribution Date,
an amount equal to the least of (a) any shortfall for the previous month in     
interest collections resulting from the timing of Payoffs made from the 15th day
of the calendar month before the Distribution Date to the last day of the month,
(b) the sum of (i) 1/12 of 0.050% of the aggregate Stated Principal Balance of  
the mortgage loans, (ii) any reinvestment income realized by the servicer       
relating to Payoffs made during the Prepayment Period and (iii) interest        
payments on the Payoffs received during the period of the first day through the 
14th day of the month of the Distribution Date and (c) 1/12 of 0.125% of the    
aggregate Stated Principal Balance of the mortgage loans. Payoffs received on   
mortgage loans from the first day through the 14th day of any month will be     
passed through to the certificateholders on the Distribution Date of the same   
month (except for Payoffs received from the Cut-Off Date through August 14,     
2005, which will be passed through to the certificateholders on the September   
2005 Distribution Date), rather than on the Distribution Date of the following  
month, together with a full month's interest for the prior month. Accordingly,  
no Compensating Interest will be payable for Payoffs received during that       
period. Payoffs received during the period from the 15th day through the last   
day of any month will be passed through on the Distribution Date in the         
following month, and, in order to provide for a full month's interest payment   
for the prior month, Compensating Interest will be passed through to            
certificateholders for that period.                                             

To the extent that the amount allocated to pay Compensating Interest is 
insufficient to cover the deficiency in interest payable as a result of the     
timing of a Payoff, or to the extent that there is an interest deficiency from a
Curtailment or the application of the Relief Act, that remaining deficiency will
be allocated to the certificates, pro rata according to the amount of interest  
to which each class of certificates would otherwise be entitled, in reduction of
that amount.                                                                    

LIBOR CERTIFICATES                                                              

The yield to investors in the LIBOR Certificates will be sensitive to   
fluctuations in LIBOR. Changes in LIBOR may not correlate with changes in       
prevailing mortgage interest rates. It is possible that lower prevailing        
mortgage interest rates, which might be expected to result in faster            
prepayments, could occur concurrently with an increased level of LIBOR.         
Conversely, higher prevailing mortgage interest rates, which would be expected  
to result in slower prepayments, could occur concurrently with a lower level of 
LIBOR.                                                                          

RATE OF PAYMENTS                                                                

 The rate of principal payments on the certificates (including the Class X
Certificates, to the extent that a portion of Net Negative Amortization has been
allocated to the principal balance of the Class X principal-only component)     
generally is directly related to the rate of principal payments on the mortgage 
loans, which may be in the form of scheduled payments, principal prepayments or 
liquidations. See 'Risk                                                         

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Factors' in this prospectus supplement and 'Yield Considerations' in the        
prospectus. All of the mortgage loans are assumable to the extent provided in   
the related mortgage note. The mortgage note for each mortgage loan provides    
that if the mortgage loan is assumed, the Rate Ceiling may be increased. As of  
the Cut-Off Date, approximately 73.5% (by aggregate principal balance) of the   
mortgage loans impose penalties for early prepayments in full (but do not impose
penalties for partial prepayments) received on or before the first anniversary  
of the origination of the mortgage loan. As of the Cut-Off Date, approximately  
8.1% (by aggregate principal balance) of the mortgage loans impose penalties for
early prepayments in full (but do not impose penalties for partial prepayments) 
received on or before the third anniversary of the origination of the mortgage  
loan. As of the Cut-Off Date, approximately 1.3% (by aggregate principal        
balance) of the mortgage loans impose penalties for early prepayments in full,  
and for partial prepayments in the event that aggregate partial prepayments made
during a 12-month period exceed 20% of the original principal balance. Those    
prepayment penalties are in effect for 30 months after the origination of those 
mortgage loans. All prepayment penalties payments remitted to the Trust with    
respect to voluntary full prepayments on the mortgage loans will be distributed 
to the holders of the Class PPP Certificates. The holders of the Class PPP      
Certificates will not receive any prepayment penalty payment remitted to the    
Trust with respect to voluntary partial prepayments; each such payment will be  
retained by the servicer as additional servicing compensation. No prepayment    
penalty payments will be available for distribution to holders of the other     
classes of certificates. See 'Description of the Mortgage Pool' in this         
prospectus supplement.                                                          

   From time to time, Washington Mutual Bank may implement programs to solicit
mortgagors of qualifying mortgage loans that it services for refinance,         
including the mortgage loans underlying the certificates. While those programs  
will not specifically target the mortgage loans underlying the certificates for 
refinance, they may have the effect of accelerating the prepayment rate of those
mortgage loans, which would adversely affect the yield on all classes of        
certificates purchased at a premium.                                            

A higher than anticipated rate of prepayments would reduce the aggregate
principal balance of the mortgage loans more quickly than expected. As a        
consequence, aggregate interest payments for the mortgage loans would be        
substantially less than expected. Therefore, a higher rate of principal         
prepayments could result in a lower than expected yield to maturity on each     
class of certificates purchased at a premium, and in some circumstances         
investors may not fully recover their initial investments. Conversely, a lower  
than expected rate of principal prepayments would reduce the return to investors
on any classes of certificates purchased at a discount, in that principal       
payments for the mortgage loans would occur later than anticipated. There can be
no assurance that certificateholders will be able to reinvest amounts received  
from the certificates at a rate that is comparable to the applicable interest   
rate on the certificates. Investors should fully consider all of the associated 
risks.                                                                          

PREPAYMENT ASSUMPTIONS                                                          

    Prepayments on mortgage loans are commonly measured relative to a prepayment
standard or model. The prepayment model used in this prospectus supplement (the 
'CONSTANT PREPAYMENT RATE' or 'CPR') assumes that the outstanding principal     
balance of a pool of mortgage loans prepays at a specified constant annual rate.
In generating monthly cash flows, this rate is converted to an equivalent       
monthly rate. A 25% CPR assumes a constant per annum rate of prepayment of 25%  
of the then outstanding principal balance of the pool of mortgage loans.        
Likewise, a 12% CPR, 15% CPR, 30% CPR and 40% CPR assumes a constant per annum  
rate of prepayment of 12%, 15%, 30% and 40%, respectively, of the then          
outstanding principal balance of the pool of mortgage loans.                    

    None of the prepayment rates purports to be either an historical description
of the prepayment experience of any pool of mortgage loans or a prediction of   
the anticipated rate of prepayment of any pool of mortgage loans, including the 
mortgage pool underlying the certificates. Furthermore, there is no assurance   
that the mortgage loans will prepay at any given percentage of the CPR. The     
actual rate of prepayments on the mortgage loans may be influenced by a variety 
of economic, geographic, social and other factors. In general, during the       
initial fixed-rate period for some of the mortgage loans underlying the         
certificates, if prevailing mortgage interest rates fall significantly below the
mortgage interest rates on those mortgage loans, those mortgage loans are likely
to be subject to higher prepayment rates than if prevailing mortgage interest   
rates remain at or above the mortgage interest rates on the mortgage loans      
underlying                                                                      

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the certificates. Conversely, during the initial fixed-rate period for those    
mortgage loans, if prevailing mortgage interest rates rise above the mortgage   
interest rates on those mortgage loans, the rate of prepayment would be expected
to decrease. A comparatively low interest-rate environment may result in a      
higher than expected rate of prepayments on all of the mortgage loans and,      
correspondingly, an earlier than expected retirement of the certificates.       

   This prospectus supplement does not describe the specific factors that will
affect the prepayment of the mortgage loans or their relative importance.       
Factors not identified in this prospectus supplement may significantly affect   
the prepayment rate of the mortgage loans. In particular, this prospectus       
supplement makes no representation as to either the percentage of the principal 
amount of the mortgage loans that will be paid as of any date or the overall    
rate of prepayment.                                                             

  For purposes of the tables in Appendix A, it is assumed (collectively, the
'MODELING ASSUMPTIONS') that the mortgage loans are comprised of the groups of  
hypothetical mortgage loans, which have the common characteristics indicated:   

GROUPS OF HYPOTHETICAL MORTGAGE LOANS 

                                                        [Enlarge/Download Table]

                                REMAINING  ORIGINAL                                             
HYPOTHETICAL  UNPAID PRINCIPAL    TERM       TERM        MORTGAGE       PASS-THROUGH            
LOAN NUMBER     BALANCE ($)     (MONTHS)   (MONTHS)  INTEREST RATE (%)    RATE (%)    MARGIN (%)
-----------     -----------     --------   --------  -----------------    --------    ----------
                                                                                                
      1            472,820.64      348       360          5.08700         4.71200      2.35000  
      2          1,022,195.73      350       360          5.08278         4.70778      2.34578  
      3          1,723,558.75      351       360          4.88142         4.50642      2.14442  
      4         30,320,905.46      352       360          4.92680         4.55180      2.18980  
      5         21,398,164.29      353       360          4.98397         4.60897      2.24697  
      6         38,853,885.40      354       360          4.92440         4.54940      2.18740  
      7        116,908,432.66      355       360          4.92556         4.55056      2.18856  
      8        118,699,332.11      356       360          4.92503         4.55003      2.18803  
      9        100,450,103.63      357       360          4.92126         4.54626      2.18426  
     10         79,642,683.66      358       360          4.89135         4.51635      2.15435  
     11          3,236,260.91      472       480          5.01280         4.63780      2.27580  
     12            889,234.02      473       480          5.05700         4.68200      2.32000  
     13          1,623,277.86      474       480          5.30331         4.92831      2.56631  
     14          3,791,285.77      475       480          4.88715         4.51215      2.15015  
     15          9,173,777.90      476       480          4.97447         4.59947      2.23747  
     16         11,635,811.98      477       480          4.87825         4.50325      2.14125  
     17          7,031,209.55      478       480          4.75992         4.38492      2.02292  
     18          8,469,227.32      348       360          5.24596         4.87096      2.50896  
     19          2,401,413.76      349       360          5.17506         4.80006      2.43806  
     20          7,809,031.99      350       360          5.16221         4.78721      2.42521  
     21          4,719,037.57      351       360          5.15138         4.77638      2.41438  
     22        129,981,474.92      352       360          5.09827         4.72327      2.36127  
     23         92,538,803.13      353       360          5.12531         4.75031      2.38831  
     24        170,853,369.04      354       360          5.04756         4.67256      2.31056  
     25        454,331,135.39      355       360          5.07276         4.69776      2.33576  
     26        505,950,178.07      356       360          5.08677         4.71177      2.34977  
     27        366,919,795.12      357       360          5.07170         4.69670      2.33470  
     28        436,685,141.71      358       360          5.04951         4.67451      2.31251  
     29          4,812,753.66      347       360          5.21962         4.84462      2.48262  
     30            935,456.23      468       480          5.29700         4.92200      2.56000  
     31            434,123.79      470       480          5.15700         4.78200      2.42000  
     32          6,039,360.60      472       480          5.15332         4.77832      2.41632  
     33          4,927,759.67      473       480          5.19469         4.81969      2.45769  
     34          5,862,411.66      474       480          5.13890         4.76390      2.40190  
     35         28,451,549.62      475       480          5.09018         4.71518      2.35318  
     36         44,022,245.75      476       480          5.07268         4.69768      2.33568  
     37         39,998,269.64      477       480          5.15071         4.77571      2.41371  
     38         36,581,512.16      478       480          5.16515         4.79015      2.42815  
     39            702,125.41      351       360          5.33700         4.96200      2.60000  
     40          4,537,724.59      352       360          5.34162         4.96662      2.60462  

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                                REMAINING  ORIGINAL                                             
HYPOTHETICAL  UNPAID PRINCIPAL    TERM       TERM        MORTGAGE       PASS-THROUGH            
LOAN NUMBER     BALANCE ($)     (MONTHS)   (MONTHS)  INTEREST RATE (%)    RATE (%)    MARGIN (%)
-----------     -----------     --------   --------  -----------------    --------    ----------
                                                                                                
     41            606,726.95      353       360          5.33700         4.96200      2.60000  
     42          2,414,203.13      354       360          5.44067         5.06567      2.70367  
     43          5,254,332.55      355       360          5.41689         5.04189      2.67989  
     44          5,945,627.54      356       360          5.37837         5.00337      2.64137  
     45         11,067,824.60      357       360          5.40000         5.02500      2.66300  
     46         10,489,282.37      358       360          5.45222         5.07722      2.71522  
     47            396,331.87      476       480          5.48700         5.11200      2.75000  
     48            649,064.00      478       480          5.60700         5.23200      2.87000  
     49          4,650,610.02      348       360          5.35683         4.98183      2.61983  
     50          6,523,414.98      349       360          5.33700         4.96200      2.60000  
     51         10,175,873.16      350       360          5.33700         4.96200      2.60000  
     52         12,453,658.52      351       360          5.33257         4.95757      2.59557  
     53         13,083,266.06      352       360          5.34443         4.96943      2.60743  
     54          3,011,372.67      353       360          5.34497         4.96997      2.60797  
     55          4,730,864.81      354       360          5.29282         4.91782      2.55582  
     56         23,820,039.89      355       360          5.28810         4.91310      2.55110  
     57         30,562,303.65      356       360          5.27805         4.90305      2.54105  
     58         26,758,154.55      357       360          5.35257         4.97757      2.61557  
     59        105,202,660.48      358       360          5.41572         5.04072      2.67872  
     60            901,609.87      347       360          5.43700         5.06200      2.70000  
     61          1,509,629.23      471       480          5.40700         5.03200      2.67000  
     62            602,754.96      474       480          5.60700         5.23200      2.87000  
     63          1,395,799.15      475       480          5.38863         5.01363      2.65163  
     64            532,964.33      476       480          5.20700         4.83200      2.47000  
     65          5,751,774.08      477       480          5.50788         5.13288      2.77088  
     66          7,742,310.04      478       480          5.32237         4.94737      2.58537  

                                                        [Enlarge/Download Table]

               MONTHS TO   MONTHS TO      NEGATIVE     RECAST                               
HYPOTHETICAL   NEXT RATE  NEXT PAYMENT  AMORTIZATION  FREQUENCY                      RATE   
LOAN NUMBER   ADJUSTMENT   ADJUSTMENT    LIMIT (%)    (MONTHS)   RATE FLOOR (%)  CEILING (%)
-----------   ----------   ----------    ---------    --------   --------------  -----------
                                                                                            
      1            1            2           125          60         2.35000         9.95000 
      2            1            4           125          60         2.34578        10.09578 
      3            1            5           118          60         2.14442         9.95000 
      4            1            6           124          60         2.18980         9.95568 
      5            1            7           124          60         2.24697        10.02428 
      6            1            8           124          60         2.18740        10.00159 
      7            1            9           124          60         2.18856         9.99111 
      8            1           10           124          60         2.18803         9.98390 
      9            1           11           124          60         2.18426        10.00158 
     10            1           12           124          60         2.15435         9.99408 
     11            1            6           125          60         2.27580         9.95000 
     12            1            7           125          60         2.32000         9.95000 
     13            1            8           125          60         2.56631        10.15000 
     14            1            9           125          60         2.15015         9.96031 
     15            1           10           125          60         2.23747         9.98238 
     16            1           11           125          60         2.14125         9.95859 
     17            1           12           125          60         2.02292         9.95746 
     18            1            2           124          60         2.50896         9.95000 
     19            1            3           119          60         2.43806         9.95000 
     20            1            4           123          60         2.42521        10.01140 
     21            1            5           122          60         2.41438        10.01438 
     22            1            6           124          60         2.36127         9.95462 
     23            1            7           124          60         2.38831         9.96598 
     24            1            8           124          60         2.31056         9.97699 
     25            1            9           125          60         2.33576         9.98290 
     26            1           10           125          60         2.34977         9.98426 
     27            1           11           125          60         2.33470         9.98537 
     28            1           12           124          60         2.31251         9.99974 
     29            1           13           125          60         2.48262         9.95000 
     30            1            2           125          60         2.56000         9.95000 
     31            1            4           125          60         2.42000         9.95000 

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               MONTHS TO   MONTHS TO      NEGATIVE     RECAST                               
HYPOTHETICAL   NEXT RATE  NEXT PAYMENT  AMORTIZATION  FREQUENCY                      RATE   
LOAN NUMBER   ADJUSTMENT   ADJUSTMENT    LIMIT (%)    (MONTHS)   RATE FLOOR (%)  CEILING (%)
-----------   ----------   ----------    ---------    --------   --------------  -----------
                                                                                            
     32            1            6           125          60         2.41632         9.95000 
     33            1            7           125          60         2.45769         9.95000 
     34            1            8           125          60         2.40190         9.96781 
     35            1            9           125          60         2.35318         9.97369 
     36            1           10           125          60         2.33568         9.96381 
     37            1           11           125          60         2.41371        10.00790 
     38            1           12           125          60         2.42815        10.01790 
     39            1            5           125          60         2.60000         9.95000 
     40            1            6           125          60         2.60462         9.95000 
     41            1            7           125          60         2.60000         9.95000 
     42            1            8           125          60         2.70367        10.04440 
     43            1            9           125          60         2.67989         9.96720 
     44            1           10           125          60         2.64137         9.95606 
     45            1           11           125          60         2.66300         9.96014 
     46            1           12           125          60         2.71522         9.95637 
     47            1           10           125          60         2.75000        10.05000 
     48            1           12           125          60         2.87000         9.95000 
     49            1            2           123          60         2.61983         9.95000 
     50            1            3           125          60         2.60000         9.95000 
     51            1            4           122          60         2.60000         9.95000 
     52            1            5           124          60         2.59557         9.95000 
     53            1            6           122          60         2.60743         9.95000 
     54            1            7           120          60         2.60797         9.95000 
     55            1            8           124          60         2.55582         9.95000 
     56            1            9           124          60         2.55110         9.95179 
     57            1           10           124          60         2.54105         9.95638 
     58            1           11           123          60         2.61557         9.96286 
     59            1           12           123          60         2.67872         9.97792 
     60            1           13           125          60         2.70000         9.95000 
     61            1            5           125          60         2.67000         9.95000 
     62            1            8           125          60         2.87000         9.95000 
     63            1            9           125          60         2.65163         9.95000 
     64            1           10           125          60         2.47000         9.95000 
     65            1           11           125          60         2.77088         9.97107 
     66            1           12           125          60         2.58537         9.96290 

and that:                                                                       

     One-Year MTA remains constant at 2.86400% and LIBOR remains
constant at 3.46375%;                                 

the servicing fee is as set forth in this prospectus  
supplement;                                           

   after the first adjustment to the Minimum Monthly Payment
for each mortgage loan, subsequent adjustments to the 
  Minimum Monthly Payment will be made every twelve months
thereafter;                                           

    there are no limitations on the adjustment of the mortgage
  interest rates on the mortgage loans other than the Rate
Ceilings and rate floors;                             

no mortgage loans are assumed;                        

      scheduled payments on all mortgage loans are received on the
first day of each month beginning September 1, 2005;  

    any Payoffs on the mortgage loans are received on the last
day of each month beginning in August 2005 and include
30 days of interest;                                  

there are no defaults or delinquencies on the mortgage
loans;                                                

     an optional termination of the Trust does not occur (except
as set forth in footnote 2 to Appendix A);            

    there are no partial prepayments on the mortgage loans and
   prepayments are computed after giving effect to scheduled
payments received on the following day;               

the mortgage loans prepay at the indicated constant   
percentages of the CPR;                               

  the date of issuance for the certificates is the Closing
Date;                                                 

      cash distributions are received by the certificateholders on
the 25th day of each month when due; and              

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the scheduled monthly payments for each hypothetical  
    mortgage loan are computed based upon its unpaid principal
      balance, mortgage interest rate and remaining term such that
    each hypothetical mortgage loan will fully amortize on its
maturity date.                                        

The approximate Class Principal Balances of the Junior Subordinate      
Certificates as of the Closing Date will be as follows: Class B-10, $12,804,000,
Class B-11, $8,003,000, Class B-12, $32,011,000, and Class B-13, $20,808,194.   

Any discrepancy between the actual characteristics of the mortgage loans
underlying the certificates and the characteristics of the hypothetical mortgage
loans set forth above may affect the percentages of the initial Class Principal 
Balances set forth in the tables in Appendix A and the weighted average lives of
the offered certificates. In addition, to the extent that the characteristics of
the actual mortgage loans and the initial Class Principal Balances differ from  
those assumed in preparing the tables in Appendix A, the outstanding Class      
Principal Balance of any class of offered certificates may be reduced to zero   
earlier or later than indicated by the tables.                                  

Variations in actual prepayment experience may increase or decrease the 
percentages of the original outstanding Class Principal Balances and the        
weighted average lives shown in the tables in Appendix A. Variations may occur  
even if the average prepayment experience of all the mortgage loans equals the  
indicated percentage of the CPR. There is no assurance, however, that           
prepayments of the mortgage loans will conform to any given percentage of the   
CPR.                                                                            

   Based on the assumptions described above, the tables in Appendix A indicate
the weighted average lives of the Class A and Senior Subordinate Certificates   
and provide the percentages of the initial outstanding Class Principal Balance  
of those classes of certificates that would be outstanding after each of the    
dates shown at various constant percentages of the CPR.                         

LACK OF HISTORICAL PREPAYMENT DATA                                              

 Washington Mutual Mortgage Securities Corp. filed with the Securities and
Exchange Commission on August 8, 2005 limited historical information concerning 
principal prepayment experience of mortgage loans of the general type included  
in the Trust; however, the prepayment experience with respect to the specific   
mortgage loans included in the Trust may differ significantly from the          
historical experience of this type of mortgage loan, and such differences may be
substantial due to the inclusion in the historical information of mortgage loans
with wider ranges of principal balances and credit scores than those in the     
mortgage loans included in the Trust, among other possible reasons. In addition,
historical data available for mortgage loans underlying mortgage pass-through   
certificates issued by the Government National Mortgage Association, Fannie Mae 
and Freddie Mac may not be comparable to prepayments expected to be experienced 
by the mortgage pool because the mortgage loans underlying the certificates may 
have characteristics that differ from the mortgage loans underlying certificates
issued by the Government National Mortgage Association, Fannie Mae and Freddie  
Mac.                                                                            

    Washington Mutual Mortgage Securities Corp. does not make any representation
that the mortgage loans will prepay in the manner or at any of the rates assumed
in the tables in Appendix A or below in ' -- Yield Considerations with Respect  
to the Class X Certificates' and ' -- Yield Considerations with Respect to the  
Senior Subordinate Certificates.' Each investor must make its own decision as to
the appropriate prepayment assumptions to be used in deciding whether or not to 
purchase any of the offered certificates. Since the rate of principal payments  
(including prepayments) on, and repurchases of, the mortgage loans will         
significantly affect the yields to maturity on the offered certificates (and    
especially the yields to maturity on the Class X and Senior Subordinate         
Certificates), prospective investors are urged to consult their investment      
advisors as to both the anticipated rate of future principal payments (including
prepayments) on the mortgage loans and the suitability of the offered           
certificates to their investment objectives.                                    

YIELD CONSIDERATIONS WITH RESPECT TO THE CLASS X CERTIFICATES                   

 The Class X Certificates generally receive only distributions of interest
(except for amounts added to their component principal balance as a result of   
the allocation of Net Negative Amortization, which is then distributed to the   
Class X Certificates as principal). The yield to maturity on the Class X        
Certificates                                                                    

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will be extremely sensitive to the level of prepayments on the mortgage loans.  
The faster that the mortgage loans prepay, the less interest the Class X        
Certificates will receive. Furthermore, the higher the interest rates on the    
mortgage loans that prepay, the less interest the Class X Certificates will     
receive. Prospective investors should fully consider the risks associated with  
an investment in the Class X Certificates, including the possibility that if the
rate of prepayments on the mortgage loans is faster than expected or an optional
termination of the Trust occurs earlier than expected, investors may not fully  
recover their initial investments.                                              

To illustrate the significance of different rates of prepayment on the  
distributions on the Class X Certificates, the table below indicates the        
approximate pre-tax yields to maturity (on a corporate bond equivalent basis)   
under the different percentages of the CPR indicated.                           

  Any differences between the assumptions and the actual characteristics and
performance of the mortgage loans and of the certificates may result in a yield 
to maturity being different from those shown in the table. DISCREPANCIES BETWEEN
ASSUMED AND ACTUAL CHARACTERISTICS AND PERFORMANCES UNDERSCORE THE HYPOTHETICAL 
NATURE OF THE TABLE, WHICH IS PROVIDED ONLY TO GIVE A GENERAL SENSE OF THE      
SENSITIVITY OF THE YIELD TO MATURITY IN VARYING PREPAYMENT SCENARIOS. In        
addition, it is highly unlikely that the mortgage loans will prepay at a        
constant level of the CPR until maturity or that all of the mortgage loans will 
prepay at the same rate. The timing of changes to the rate of prepayments may   
significantly affect the actual yield to maturity to an investor, even if the   
average rate of prepayments is consistent with an investor's expectation. In    
general, the earlier a payment of principal on the mortgage loans, the greater  
the effect on an investor's yield to maturity. As a result, the effect on an    
investor's yield to maturity of prepayments occurring at a rate higher (or      
lower) than the rate anticipated by the investor during the period immediately  
following the issuance of the certificates will not be equally offset by a later
like reduction (or increase) in the rate of prepayments.                        

    The following sensitivity table for the Class X Certificates is based on the
Modeling Assumptions and assumes further that the certificates are purchased at 
the price set forth in the table plus accrued interest from the Cut-Off Date.   
There can be no assurance that the mortgage loans will have the assumed         
characteristics or will prepay at any of the rates shown below, that the        
purchase price of the certificates will be as assumed or that the pre-tax yield 
to maturity will correspond to any of the pre-tax yields shown in the table     
below. The actual price to be paid on the Class X Certificates has not been     
determined and will depend on the characteristics of the mortgage pool as       
ultimately constituted. In addition to any other factors an investor may        
consider material, each investor must make its own decision as to the           
appropriate prepayment assumptions to be used in deciding whether or not to     
purchase a class of offered certificates.                                       

PRE-TAX YIELD TO MATURITY OF THE CLASS X CERTIFICATES AT AN 
ASSUMED PURCHASE PRICE OF 1.84375% OF THE INITIAL CLASS X NOTIONAL AMOUNT 
PLUS ACCRUED INTEREST FROM THE CUT-OFF DATE 

                                                                [Download Table]

          PERCENTAGE OF THE CPR            
------------------------------------------ 
 12%      15%      25%      30%      40%   
 ---      ---      ---      ---      ---   
                                           
35.55%   31.32%   16.43%    8.25%   (9.38%)

   Based on a constant prepayment rate of approximately 34.84% of the CPR, the
assumed purchase price above, plus accrued interest from the Cut-Off Date, and  
the assumptions described above, the pre-tax yield to maturity of the Class X   
Certificates would be approximately 0%. If the actual prepayment rate were to   
exceed the rate assumed above, even for one month, while equaling that rate for 
all other months, an investor in the Class X Certificates would not fully       
recover the initial purchase price of the certificates.                         

   The pre-tax yields to maturity shown in the preceding table were calculated
by determining the monthly discount rates (whether positive or negative), which,
when applied to the assumed streams of cash flows to be paid on the             
certificates, would cause the discounted present values of those assumed streams
of cash flows to equal the assumed purchase price, plus accrued interest. These 
monthly discount rates were converted to corporate bond equivalent rates, which 
are higher than the monthly discount rates because they are based on semiannual 
compounding. These yields to maturity do not take into account the different    
interest rates at which investors may be able to reinvest funds received by them
as distributions                                                                

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on these certificates and thus do not reflect the return on any investment in   
these certificates when any reinvestment rates other than the discount rates are
considered.                                                                     

YIELD CONSIDERATIONS WITH RESPECT TO THE SENIOR SUBORDINATE CERTIFICATES        

If the aggregate Class Principal Balance of the Junior Subordinate      
Certificates is reduced to zero, the yield to maturity on the Senior Subordinate
Certificates will become extremely sensitive to losses on the mortgage loans and
the timing of those losses, because the entire amount of those losses will      
generally be allocated to the Senior Subordinate Certificates in reverse        
numerical order. The aggregate initial Class Principal Balance of the Junior    
Subordinate Certificates is equal to approximately 2.30% of the aggregate       
principal balance of the mortgage loans as of the Cut-Off Date.                 

  For the Senior Subordinate Certificates, this prospectus supplement uses a
standard default assumption, or SDA, that represents an assumed default rate,   
which is a percentage of the outstanding principal balance of a hypothetical    
pool of mortgage loans. The SDA does not describe historical default experience 
or predict future default rates of any pool of mortgage loans, including the    
mortgage loans in the trust.                                                    

A 100% SDA assumes constant annual default rates on the then outstanding
principal balance of the mortgage loans, as follows:                            

                                                                [Download Table]
                                                                   
1st month:                          0.02%                          

2nd through 29th month:             increasing by 0.02% each month 

30th through 60th month:            0.60%                          

61st through 120th month:           declining by 0.0095% each month

121st month and after:              0.03%                          

  The tables below assume that there is no delay between the default and the
liquidation of the mortgage loans. In the tables below, an SDA of 0% assumes no 
defaults, an SDA of 200% assumes default rates 2.00 times 100% SDA, and so      
forth. However, it is highly unlikely that the prepayments or realized losses on
the mortgage loans will occur as the following tables assume, and, as a result, 
the actual pre-tax yields to maturity on the Senior Subordinate Certificates are
highly likely to differ from those shown in the tables.                         

 The following tables show the sensitivity of the yield to maturity on the
Senior Subordinate Certificates to different prepayment rates and levels of     
defaults based on the Modeling Assumptions, except that it has been assumed     
that:                                                                           

    mortgage loan defaults occur on the last day of each month
      at the SDA percentages in the tables, and defaulted mortgage
loans are immediately liquidated;                     

    each liquidation of a defaulted mortgage loan results in a
      realized loss allocable to principal equal to the percentage
    indicated, the loss severity percentage, multiplied by the
principal balances of the mortgage loans assumed to be
liquidated;                                           

there are no delinquencies on the mortgage loans, and 
    principal payments on the mortgage loans, other than those
    on mortgage loans assumed to be liquidated, will be timely
received together with prepayments, if any, at the    
     respective constant percentages of the CPR set forth in the
table;                                                

     the purchase prices of the Class B-1, Class B-2, Class B-3,
   Class B-4, Class B-5, Class B-6, Class B-7, Class B-8 and
  Class B-9 Certificates will be approximately 100.00000%,
     100.00000%, 100.00000%, 100.00000%, 100.00000%, 100.00000%,
    99.09375%, 98.00000% and 95.00000%, respectively, of their
respective Class Principal Balances;                  

    realized losses on liquidation of the mortgage loans occur
   at a rate of 20% and 40% (as indicated in the table under
   the column 'Loss Severity Percentage') of the outstanding
      principal balance of defaulted mortgage loans at the time of
default in the month in which the mortgage loans first
default; and                                          

      all scheduled payments on mortgage loans are advanced by the
servicer whether or not received from the related     
mortgagors.                                           

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    The rate of distributions in reduction of the Class Principal Balance of any
class of Senior Subordinate Certificates will be related to the actual          
amortization schedule of the mortgage loans; accordingly, the interest          
distributions and distributions in reduction of the Class Principal Balances of 
the Senior Subordinate Certificates may result in yields to maturity that differ
from those reflected below.                                                     

The tables below are for illustrative purposes only and this prospectus 
supplement does not represent that these assumptions are reasonable or that the 
actual rates of prepayment and liquidation and loss severity experience of the  
mortgage loans will in any way correspond to any of the assumptions made in this
prospectus supplement. It is possible that those mortgage loans that are more   
likely to default are also less likely to experience prepayments, which means   
that higher prepayment speeds would not necessarily reduce the expected amount  
of realized losses. In addition, it is unlikely that liquidations will occur in 
the month of default and the timing of liquidations may cause the pre-tax yield 
to maturity of the Senior Subordinate Certificates to differ from those shown   
below.                                                                          

Differences between the assumptions in the tables and the actual        
characteristics and performance of the mortgage loans will likely result in     
different yields from those shown in the tables. Because differences between    
assumed and actual characteristics can affect the performance of the            
certificates, investors should understand the hypothetical nature of the tables,
which give only a general sense of the sensitivity of yields to maturity under  
varying, but not all, realized loss and prepayment scenarios.                   

SENSITIVITY OF PRE-TAX YIELD TO MATURITY
OF THE SENIOR SUBORDINATE CERTIFICATES TO 
PREPAYMENTS AND REALIZED LOSSES 

CLASS B-1 CERTIFICATES

                                                                [Download Table]

                                                 LOSS   
PERCENTAGE OF                                  SEVERITY 
     SDA        12% CPR   25% CPR   40% CPR   PERCENTAGE
-------------   -------   -------   -------   ----------
                                                        
      0%         4.1%      4.1%      4.1%        N/A    
    100%         4.1%      4.1%      4.1%        20%    
    100%         4.1%      4.1%      4.1%        40%    
    200%         4.1%      4.1%      4.1%        20%    
    200%         4.1%      4.1%      4.1%        40%    

CLASS B-2 CERTIFICATES

                                                                [Download Table]

                                                 LOSS   
PERCENTAGE OF                                  SEVERITY 
     SDA        12% CPR   25% CPR   40% CPR   PERCENTAGE
-------------   -------   -------   -------   ----------
                                                        
      0%         4.1%      4.2%      4.2%        N/A    
    100%         4.1%      4.2%      4.2%        20%    
    100%         4.1%      4.2%      4.2%        40%    
    200%         4.1%      4.2%      4.2%        20%    
    200%         4.1%      4.2%      4.2%        40%    

CLASS B-3 CERTIFICATES

                                                                [Download Table]

                                                 LOSS   
PERCENTAGE OF                                  SEVERITY 
     SDA        12% CPR   25% CPR   40% CPR   PERCENTAGE
-------------   -------   -------   -------   ----------
                                                        
      0%         4.2%      4.2%      4.2%        N/A    
    100%         4.2%      4.2%      4.2%        20%    
    100%         4.2%      4.2%      4.2%        40%    
    200%         4.2%      4.2%      4.2%        20%    
    200%         4.2%      4.2%      4.2%        40%    

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CLASS B-4 CERTIFICATES

                                                                [Download Table]

                                                 LOSS   
PERCENTAGE OF                                  SEVERITY 
     SDA        12% CPR   25% CPR   40% CPR   PERCENTAGE
-------------   -------   -------   -------   ----------
                                                        
      0%         4.4%      4.4%      4.4%        N/A    
    100%         4.4%      4.4%      4.4%        20%    
    100%         4.4%      4.4%      4.4%        40%    
    200%         4.4%      4.4%      4.4%        20%    
    200%         4.4%      4.4%      4.4%        40%    

CLASS B-5 CERTIFICATES

                                                                [Download Table]

                                                 LOSS   
PERCENTAGE OF                                  SEVERITY 
     SDA        12% CPR   25% CPR   40% CPR   PERCENTAGE
-------------   -------   -------   -------   ----------
                                                        
      0%         4.5%      4.5%      4.5%        N/A    
    100%         4.5%      4.5%      4.5%        20%    
    100%         4.5%      4.5%      4.5%        40%    
    200%         4.5%      4.5%      4.5%        20%    
    200%         4.5%      4.5%      4.5%        40%    

CLASS B-6 CERTIFICATES

                                                                [Download Table]

                                                 LOSS   
PERCENTAGE OF                                  SEVERITY 
     SDA        12% CPR   25% CPR   40% CPR   PERCENTAGE
-------------   -------   -------   -------   ----------
                                                        
      0%         4.6%      4.6%      4.6%        N/A    
    100%         4.6%      4.6%      4.6%        20%    
    100%         4.6%      4.6%      4.6%        40%    
    200%         4.6%      4.6%      4.6%        20%    
    200%         4.6%      4.6%      4.6%        40%    

CLASS B-7 CERTIFICATES

                                                                [Download Table]

                                                 LOSS   
PERCENTAGE OF                                  SEVERITY 
     SDA        12% CPR   25% CPR   40% CPR   PERCENTAGE
-------------   -------   -------   -------   ----------
                                                        
      0%         4.9%      4.9%      5.0%        N/A    
    100%         4.9%      5.0%      5.1%        20%    
    100%         4.9%      4.9%      5.1%        40%    
    200%         4.9%      5.0%      5.1%        20%    
    200%         4.9%      5.0%      5.1%        40%    

CLASS B-8 CERTIFICATES

                                                                [Download Table]

                                                 LOSS   
PERCENTAGE OF                                  SEVERITY 
     SDA        12% CPR   25% CPR   40% CPR   PERCENTAGE
-------------   -------   -------   -------   ----------
                                                        
      0%         5.0%      5.2%      5.4%        N/A    
    100%         5.0%      5.2%      5.4%        20%    
    100%         5.0%      5.2%      5.4%        40%    
    200%         5.0%      5.2%      5.4%        20%    
    200%         5.0%      5.2%      5.4%        40%    

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CLASS B-9 CERTIFICATES

                                                                [Download Table]

                                                 LOSS   
PERCENTAGE OF                                  SEVERITY 
     SDA        12% CPR   25% CPR   40% CPR   PERCENTAGE
-------------   -------   -------   -------   ----------
                                                        
      0%         5.4%      5.8%      6.3%        N/A    
    100%         5.4%      5.8%      6.3%        20%    
    100%         5.4%      5.8%      6.3%        40%    
    200%         5.4%      5.9%      6.3%        20%    
    200%         5.3%      5.8%      6.3%        40%    

  The following table sets forth the amount of realized losses that would be
incurred with respect to the certificates in the aggregate under each of the    
loss scenarios in the nine preceding tables, expressed as a percentage of the   
aggregate outstanding principal balance of the mortgage loans as of the Cut-Off 
Date:                                                                           

AGGREGATE REALIZED LOSSES 

                                                                [Download Table]

                                                 LOSS   
PERCENTAGE OF                                  SEVERITY 
     SDA        12% CPR   25% CPR   40% CPR   PERCENTAGE
-------------   -------   -------   -------   ----------
                                                        
    100%         0.4%      0.3%      0.1%        20%    
    100%         0.9%      0.5%      0.3%        40%    
    200%         0.9%      0.5%      0.3%        20%    
    200%         1.7%      1.0%      0.6%        40%    

  The characteristics of the mortgage loans underlying the certificates will
not correspond exactly to those assumed in preparing the tables above. The yield
to maturity of each class of Senior Subordinate Certificates therefore will     
differ even if all the mortgage loans prepay monthly at the related assumed     
prepayment rate. In addition, it is not likely that the mortgage loans will     
prepay at the same percentage of the CPR, and the timing of changes in the rate 
of prepayments may affect significantly the yield to maturity received by a     
holder of a class of Senior Subordinate Certificates.                           

ADDITIONAL YIELD CONSIDERATIONS APPLICABLE SOLELY TO THE CLASS R CERTIFICATES   

The Class R Certificateholders' after-tax rate of return on their       
certificates will reflect their pre-tax rate of return, reduced by the taxes    
required to be paid with respect to the Class R Certificates. Holders of the    
Class R Certificates may have tax liabilities with respect to their certificates
during the early years of the REMICs' term that substantially exceed any        
distributions payable during those years. In addition, holders of the Class R   
Certificates may have tax liabilities with respect to their certificates the    
present value of which substantially exceeds the present value of distributions 
payable on their certificates and of any tax benefits that may arise with       
respect thereto. Accordingly, the after-tax rate of return on the Class R       
Certificates may be negative or may otherwise be significantly adversely        
affected. The timing and amount of taxable income attributable to the Class R   
Certificates will depend on, among other things, the timing and amounts of      
prepayments and losses experienced by the mortgage pool.                        

  The Class R Certificateholders should consult their own tax advisors as to
the effect of taxes and the receipt of any payments received in connection with 
the purchase of the Class R Certificates on after-tax rates of return on the    
Class R Certificates. See 'Certain Federal Income Tax Consequences' in this     
prospectus supplement and in the prospectus.                                    

ADDITIONAL INFORMATION                                                          

Washington Mutual Mortgage Securities Corp. intends to file with the    
Securities and Exchange Commission additional yield tables and other            
computational materials for one or more classes of the offered certificates on a
Current Report on Form 8-K. Those tables and materials were prepared by the     
underwriters at the request of prospective investors, based on assumptions      
provided by, and satisfying the special requirements of, those prospective      
investors. Those tables and materials are preliminary in nature, and investors  
are urged to read carefully the information in this prospectus supplement.      

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CREDIT ENHANCEMENTS 

SUBORDINATION                                                                   

  The Senior Certificates receive distributions of interest and principal to
which they are entitled before distributions of interest or principal to the    
Subordinate Certificates. No class of Subordinate Certificates will receive     
distributions of interest or principal on any Distribution Date until the       
Subordinate Certificates senior to that class have received all distributions of
interest and principal due on or before the Distribution Date. See 'Description 
of the Certificates -- Priority of Distributions' in this prospectus supplement.

  In addition, the holders of the Class A Certificates will have the benefit
of the Yield Maintenance Agreement, which is intended to partially mitigate the 
risk to those Class A Certificates that LIBOR plus the related margin will      
exceed the Adjusted Weighted Average Pass-Through Rate.                         

   Losses on mortgage loans will be allocated, in each case, until their Class
Principal Balances have been reduced to zero, first, to the Junior Subordinate  
Certificates in reverse numerical order; second, to the Class B-9 Certificates; 
third, to the Class B-8 Certificates; fourth, to the Class B-7 Certificates;    
fifth, to the Class B-6 Certificates; sixth, to the Class B-5 Certificates;     
seventh, to the Class B-4 Certificates; eighth, to the Class B-3 Certificates;  
ninth, to the Class B-2 Certificates; tenth, to the Class B-1 Certificates; and 
eleventh, to the Senior Certificates as described under 'Description of the     
Certificates -- Subordination and Allocation of Losses' in this prospectus      
supplement; provided, however, that after the Class Principal Balances of all of
the Subordinate Certificates have been reduced to zero, any loss that would     
otherwise be allocated to the Class A-1A Certificates will be allocated         
(i) first, to the Class A-1C1, Class A-1C2, Class A-1C3 and Class A-1C4         
Certificates, pro rata based on Class Principal Balance, until their respective 
Class Principal Balances have each been reduced to zero and (ii) second, to the 
Class A-1B1, Class A-1B2 and Class A-1B3 Certificates, pro rata based on Class  
Principal Balance, until their respective Class Principal Balances have each    
been reduced to zero; and provided, further, that any loss that would otherwise 
be allocated to the Class A-1B1, Class A-1B2 or Class A-1B3 Certificates will be
allocated to the Class A-1C1, Class A-1C2, Class A-1C3 and Class A-1C4          
Certificates, pro rata based on Class Principal Balance, until their respective 
Class Principal Balances have each been reduced to zero.                        

SHIFTING OF INTERESTS                                                           

 The Senior Certificates in the aggregate generally will receive their pro
rata share of scheduled principal payments received with respect to the mortgage
loans on each Distribution Date. In addition, unless credit enhancement to the  
Senior Certificates has reached a specified level and the delinquencies and     
losses on the mortgage loans do not exceed specified limits, the Senior         
Certificates will receive 100% of principal prepayments received with respect to
the mortgage loans, net of any portion thereof applied to reduce negative       
amortization, until the tenth anniversary of the first Distribution Date. During
the next four years, the Senior Certificates generally will receive a           
disproportionately large, but decreasing, share of principal prepayments        
received with respect to the mortgage loans. This will result in an acceleration
of the amortization of the Senior Certificates, enhancing the likelihood that   
holders of the Senior Certificates will be paid the full amount of principal to 
which they are entitled. See the second and third paragraphs of 'Description of 
the Certificates -- Distributions of Principal -- Principal Prepayments' in this
prospectus supplement for important limitations on the accelerated amortization 
of the Senior Certificates.                                                     

YIELD MAINTENANCE AGREEMENT 

 The holders of the Class A Certificates will have the benefit of payments
pursuant to the Yield Maintenance Agreement, which is intended to partially     
mitigate the risk to the Class A Certificates that LIBOR plus the related margin
will exceed the Adjusted Weighted Average Pass-Through Rate. On each            
Distribution Date (other than the first Distribution Date), payments under the  
Yield Maintenance Agreement will generally equal the product of (i) a ratio, the
numerator of which is the actual number of days in the accrual period and the   
denominator of which is 360, (ii) the excess, if any, of (x) LIBOR, subject to a
maximum of 10.17%, over (y) the related cap strike rate and (iii) the lesser    
of (x) the aggregate Class Principal Balance of the Class A Certificates        
and (y) the related Yield Maintenance Notional Balance. The Cap Counterparty    
will be obligated to make payments under the Yield Maintenance Agreement to the 
Trust, for the benefit of the Class A Certificates, when LIBOR exceeds the      
related cap                                                                     

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strike rate specified on Schedule 1 to this prospectus supplement for that      
Distribution Date, provided that such payment is limited when LIBOR exceeds     
10.17%.                                                                         

   On each Distribution Date on which a Carryover Shortfall Amount is required
to be paid, the trustee will withdraw from funds available on deposit in the    
Certificate Account amounts to cover any Carryover Shortfall Amounts with       
respect to the Class A Certificates. There can be no assurance, however, that   
funds will be available to pay any such Carryover Shortfall Amounts             
distributable to the Class A Certificates on such Distribution Date or          
subsequent Distribution Dates pursuant to the Yield Maintenance Agreement.      
Payments, if any, made pursuant to the Yield Maintenance Agreement will start on
the Distribution Date in October 2005. After the Distribution Date in February  
2014, the Yield Maintenance Notional Balance will be equal to zero and the Yield
Maintenance Agreement will be terminated.                                       

CERTAIN FEDERAL INCOME TAX CONSEQUENCES 

    For federal income tax purposes, the servicer will cause two REMIC elections
to be made with respect to the Trust. The offered certificates, other than the  
Class R Certificates, will represent ownership of REMIC regular interests       
coupled, in the case of the Class A Certificates and the Class B Certificates,  
with rights to receive payments under one or more cap agreements and, in the    
case of the Class X Certificates, with the obligation to make payments under a  
cap agreement, and will generally represent ownership of debt for federal income
tax purposes, to the extent of the REMIC regular interest portion thereof. For  
federal income tax purposes the Class R Certificates will represent ownership of
the residual interests in each of REMIC I and REMIC II.                         

    All interest and original issue discount ('OID') on the offered certificates
will be includable in certificateholders' income using the accrual method of    
accounting regardless of the certificateholders' usual methods of accounting. In
preparing federal income tax reports to certificateholders and the Internal     
Revenue Service, Washington Mutual Bank, as servicer, will treat the            
Certificates as having been issued with OID. The prepayment assumption that will
be used in determining the rate of accrual of OID and market discount, if any,  
for federal income tax purposes is 25% CPR, as described in this prospectus     
supplement under 'Yield and Prepayment Considerations.' Neither Washington      
Mutual Mortgage Securities Corp. nor Washington Mutual Bank represents that the 
mortgage loans will prepay at any given percentage of the CPR. Holders of the   
offered certificates should see 'Special Tax Considerations Applicable to the   
Class A and Class B Certificates' and ' -- Taxation of the Cap Agreement Portion
of the Class X Certificates' in this prospectus supplement.                     

In certain circumstances, OID regulations (as described under 'Certain  
Federal Income Tax Consequences' in the prospectus) permit the holder of a debt 
instrument to recognize OID under a method that differs from that used by the   
issuer. Accordingly, it is possible that the holder of a certificate may be able
to select a method for recognizing OID that differs from that used by Washington
Mutual Bank. in preparing reports to the certificateholders and the Internal    
Revenue Service.                                                                

 If actual prepayments differ sufficiently from the prepayment assumption,
the calculation of OID for certain classes of offered certificates might produce
a negative number for certain accrual periods. If that happens,                 
certificateholders will not be entitled to a deduction for that amount, but will
be required to carry that amount forward as an offset to OID, if any, accruing  
in future accrual periods.                                                      

Certain classes of certificates may be treated for federal income tax   
purposes as having been issued at a premium. Whether any holder of a certificate
will be treated as holding a certificate with amortizable bond premium will     
depend on the certificateholder's purchase price and the distributions remaining
to be made on the certificate when the certificateholder acquires it. The use of
an assumption that there will be no prepayments might be required in calculating
the amount of premium to be amortized in each period. Holders of those classes  
of certificates should consult their own tax advisors regarding the possibility 
of making an election to amortize any premium. See 'Certain Federal Income Tax  
Consequences -- Taxation of Owners of REMIC Regular Certificates -- Original    
Issue Discount' and ' -- Market Discount and Premium' in the prospectus.        

 The offered certificates, to the extent they represent ownership of REMIC
regular interests, will generally be treated as 'qualifying real property loans'
for mutual savings banks and domestic building and loan associations, 'loans    
secured by an interest in real property' for domestic building and loan         
associations, and 'real estate assets' for real estate investment trusts, or    
REITs, in the same proportion                                                   

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that the REMIC assets would be so treated. In addition, interest on the offered 
certificates, exclusive of any interest payable to the Class A and Class B      
Certificates in respect of Carryover Shortfall Amounts, will generally be       
treated as 'interest on obligations secured by mortgages on real property' for  
REITs in the same proportion that the REMIC income would be so treated. See     
'Certain Federal Income Tax Consequences' in the prospectus.                    

SPECIAL TAX CONSIDERATIONS APPLICABLE TO THE CLASS A AND CLASS B CERTIFICATES   

Each holder of a Class A Certificate is deemed to own an undivided      
beneficial ownership interest in two assets, a REMIC regular interest and an    
interest in (a) payments to be made under the Yield Maintenance Agreement and   
(b) payments required to be made in reduction of Carryover Shortfall Amounts    
that reduce the entitlement of the Class X Certificates to payments of interest 
(the 'CLASS X CAP AMOUNT'). Each holder of a Class B Certificate is deemed to   
own an undivided beneficial ownership interest in two assets, a REMIC regular   
interest and an interest in payments required to be made in reduction of        
Carryover Shortfall Amounts that reduce the entitlement of the Class X          
Certificates to payments of interest (the 'CLASS X CAP AMOUNT'). The treatment  
of amounts received by the holder of a Class A or a Class B Certificate under   
such certificateholder's right to receive payments under the Yield Maintenance  
Agreement or the Class X Cap Amount will depend on the portion, if any, of such 
holder's purchase price allocable thereto. Under the REMIC regulations, each    
holder of a Class A or a Class B Certificate must allocate its purchase price   
for that certificate between its undivided interest in the REMIC regular        
interest and its undivided interest in the right to receive payments under the  
Yield Maintenance Agreement or the Class X Cap Amount in accordance with the    
relative fair market values of each property right. The Trust intends to treat  
payments made to the holders of the Class A or Class B Certificates with respect
to the payments under the Yield Maintenance Agreement and the Class X Cap Amount
as includible in income based on the tax regulations relating to notional       
principal contracts. The OID regulations provide that the Trust's allocation of 
the issue price is binding on all holders unless the holder explicitly discloses
on its tax return that its allocation is different from the Trust's allocation. 
Under the REMIC regulations, the Trust is required to account for the REMIC     
regular interest and the right to receive payments under the Yield Maintenance  
Agreement and the Class X Cap Amount as discrete property rights. It is possible
that the right to receive payments under the Yield Maintenance Agreement could  
be treated as a partnership among the holders of the Class A Certificates, on   
the one hand, and Class X Certificates, on the other hand, in which case holders
of the Class A Certificates would be subject to potentially different timing of 
income and foreign holders of the offered certificates could be subject to      
withholding in respect of any payments under the Yield Maintenance Agreement.   
Holders of the Class A or Class B Certificates are advised to consult their own 
tax advisors regarding the allocation of issue price, timing, character and     
source of income and deductions resulting from the ownership of their           
certificates. Treasury regulations have been promulgated under Section 1275 of  
the Internal Revenue Code generally providing for the integration of a          
'qualifying debt instrument' with a hedge if the combined cash flows of the     
components are substantially equivalent to the cash flows on a variable rate    
debt instrument. However, such regulations specifically disallow integration of 
debt instruments subject to Section 1272(a)(6) of the Internal Revenue Code.    
Therefore, holders of the Class A or Class B Certificates will be unable to use 
the integration method provided for under such regulations with respect to such 
certificates. If the Trust's treatment of payments under the Yield Maintenance  
Agreement and the Class X Cap Amount is respected, ownership of the rights to   
the payments under the Yield Maintenance Agreement and the Class X Cap Amount   
will nevertheless entitle the owner to amortize the separate price paid for the 
right to the payments under the Yield Maintenance Agreement and the Class X Cap 
Amount under the notional principal contract regulations.                       

In the event that the right to receive the payments under the Yield     
Maintenance Agreement and the Class X Cap Amount is characterized as a 'notional
principal contract' for federal income tax purposes, upon the sale of a Class A 
or Class B Certificate, the amount of the sale allocated to the selling         
certificateholder's right to receive payments under the Yield Maintenance       
Agreement or the Class X Cap Amount would be considered a 'termination payment' 
under the notional principal contract regulations allocable to the related      
certificate. A holder of a Class A or Class B Certificate would have gain or    
loss from such a termination of the right to receive payments in respect of the 
payments under the Yield Maintenance Agreement or the Class X Cap Amount equal  
to (i) any termination payment it received or                                   

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is deemed to have received minus (ii) the unamortized portion of any amount     
paid, or deemed paid, by the certificateholder upon entering into or acquiring  
its interest in the right to receive payments under the Yield Maintenance       
Agreement or the Class X Cap Amount.                                            

   Gain or loss realized upon the termination of the right to receive payments
under the Yield Maintenance Agreement or the Class X Cap Amounts will generally 
be treated as capital gain or loss. Moreover, in the case of a bank or thrift   
institution, Internal Revenue Code Section 582(c) would likely not apply to     
treat such gain or loss as ordinary.                                            

TAXATION OF THE CAP AGREEMENT PORTION OF THE CLASS X CERTIFICATES               

   Any portion of a purchaser's investment in a Class X Certificate treated by
such purchaser as representing the obligation to make payments under a cap      
agreement would be treated as an interest in a notional principal contract. To  
the extent that the obligation of the holder of the Class X Certificate under   
the cap agreement had a negative value at the time of purchase, the holder of   
the Class X Certificate would be treated as having paid an amount equal its     
purchase price for the Class X Certificate increased by a positive amount equal 
to the negative value of the obligation under the cap agreement for the REMIC   
regular interest represented by the Class X Certificate and to have received a  
payment equal to such positive amount as a premium for its obligation under the 
cap agreement. The holders of the Class X Certificates will be required to      
accrue interest payable from the REMICs included in the Trust in amounts equal  
to the excess, if any, in each period of the Weighted Average Pass-Through Rate 
over the weighted average of the interest rates payable in that period on the   
certificates having interest rates lower than the Weighted Average Pass-Through 
Rate applied to a notional balance equal to the aggregate Class Principal       
Balance of those certificates having certificate interest rates lower than the  
Weighted Average Pass-Through Rate for that period together with interest at the
Weighted Average Pass-Through Rate on the principal balance of the Class X      
principal-only component. The holders of the Class X Certificates will then be  
treated as having a payment obligation under a cap agreement for that period in 
an amount equal to the aggregate of (i) the Class A Certificates having interest
rates in excess of the Adjusted Weighted Average Pass-Through Rate and (ii) the 
Class B Certificates having interest rates in excess of the Weighted Average    
Pass-Through Rate, of such excess for such class applied to the Class Principal 
Balance of such class. The Swap Regulations specify rules for accounting for    
income from and deduction of payments made under obligations such as the cap    
agreement. Under the Swap Regulations, deductions in respect of the obligation  
to make payments under a cap agreement would be taken into account for the      
taxable period to which they relate, which generally would approximate accrual  
basis accounting regardless of an investor's usual method of tax accounting.    
Such deductions would be ordinary deductions. The Swap Regulations further      
provide that an investor in certificate would take into income any premium      
received for the obligation to make payments under a cap agreement over the term
of that obligation, generally by allocating it to each period in accordance with
the prices of a series of cash-settled option agreements that reflect the       
specified index and notional amount (i.e., any excess of the certificate rates  
over the Weighted Average Pass-Through Rate and the respective Class Principal  
Balances of the certificates) expiring in each period. Under the Swap           
Regulations, straight-line or accelerated amortization generally would be       
impermissible. The Swap Regulations also permit a simplified alternative        
allocation methodology called the 'level payment method, under which the premium
allocable to the obligation to make payments under a cap agreement would be     
allocated to each period on the basis of the principal portion of each of a     
series of equal payments having a discounted present value equal to such        
premium. There is no explicit authority with respect to the character of such   
amortization inclusions, although they are generally regarded as ordinary items.
Payments made by the Trust to certificateholders in respect of the cap agreement
and allocable to investors in the Class X Certificates that are individuals may 
be treated as investment expenses subject to the limitations on deductibility   
imposed by Section 67 of the Internal Revenue Code.                             

Holders of the Class X Certificates should be aware that the effect of  
allocating to the REMIC regular interest portion of their certificate a purchase
price in excess of their purchase price for the entire certificate would be to  
decrease the amount of OID associated with their certificate. It is expected    
that an investor's amortization of any portion of the premium they are deemed to
have received for the obligation to make payments under a cap agreement would   
offset such reduction in OID, but the degree of offset in any given period would
depend upon the applicable amortization methodology and upon the treatment of   

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such amortization as an inclusion in ordinary income, each as discussed above.  
Although dependent upon the applicable discount rate, the annual amount of      
offset should be relatively complete in the case of an investor amortizing the  
premium allocable to the obligation to make payments under a cap agreement under
the 'level payment' method described above.                                     

   On disposing of a Class X Certificate, a holder will recognize gain or loss
with respect to the related REMIC regular interest, and separately will be      
deemed to have made a payment to be relieved of the obligation to make payments 
under a cap agreement. The gain or loss with respect to the REMIC regular       
interest will be the excess of the amount deemed realized in respect thereof    
over its adjusted basis; the amount realized will be the sale price for the     
Class X Certificate increased by a positive amount equal to the negative value  
of the obligation under the cap agreement at the time of disposition. Such gain 
or loss generally will be capital gain or loss, the term of which will be based 
on the period such holder held the certificate. The deemed payment to be        
relieved of the cap agreement obligation will equal a positive amount           
corresponding to the negative value of the cap agreement obligation. There is   
limited authority on the treatment of any such payment, or on the treatment of  
any unamortized premium received by the holder in connection with undertaking   
the cap agreement obligation upon acquiring the Class X Certificate, although   
such items likely would be current items of income and deduction at the time of 
the disposition. Although it is expected that such payment would give rise to an
ordinary deduction, the Internal Revenue Service could contend that it          
represents a capital loss. Likewise, although it is expected that the           
unamortized premium would be treated as ordinary income, it is possible that it 
could constitute capital gain. As a result, prospective investors are cautioned 
to consult their own advisors on the appropriate character of such income and   
deduction. Further, to the extent that the deemed payment constitutes an item of
ordinary deduction, it may be subject to the limitations on deductibility       
imposed by Section 67 of the Internal Revenue Code as discussed above.          

SPECIAL TAX CONSIDERATIONS APPLICABLE TO THE RESIDUAL CERTIFICATES              

   The Internal Revenue Service has issued regulations under the provisions of
the Internal Revenue Code related to REMICs that significantly affect holders of
the Residual Certificates. The REMIC regulations impose restrictions on the     
transfer or acquisition of certain residual interests, including the Residual   
Certificates. In addition, the REMIC regulations contain restrictions that apply
to the transfer of 'noneconomic' residual interests to U.S. Persons. Pursuant to
the pooling agreement, the Residual Certificates may not be transferred to      
non-U.S. Persons.                                                               

The REMIC Regulations provide that a transfer to a U.S. Person of       
'noneconomic' residual interests will be disregarded for all federal income tax 
purposes, and that the purported transferor of 'noneconomic' residual interests 
will continue to remain liable for any taxes due with respect to the income on  
those residual interests, unless 'no significant purpose of the transfer was to 
impede the assessment or collection of tax.' Based on the REMIC Regulations, the
Residual Certificates may constitute noneconomic residual interests during some 
or all of their terms for purposes of the REMIC Regulations and, accordingly,   
unless no significant purpose of a transfer is to impede the assessment or      
collection of tax, transfers of the Residual Certificates may be disregarded and
purported transferors may remain liable for any taxes due with respect to the   
income on the Residual Certificates. All transfers of the Residual Certificates 
will be subject to certain restrictions under the terms of the pooling agreement
that are intended to reduce the possibility of any transfer being disregarded to
the extent that the Residual Certificates constitute noneconomic residual       
interests. The Internal Revenue Service has issued final REMIC regulations that 
add to the conditions necessary to assure that a transfer of a noneconomic      
residual interest would be respected. The additional conditions require that the
transferee represent that it will not cause the income to be 'attributable to a 
foreign permanent establishment or fixed base (within the meaning of an         
applicable income tax treaty) of the transferee or another U.S. taxpayer' and   
either (i) the amount received by the transferee be no less on a present value  
basis than the present value of the net tax detriment attributable to holding   
the residual interest reduced by the present value of the projected payments to 
be received on the residual interest or (ii) the transfer is to a domestic      
taxable corporation with specified large amounts of gross and net assets and    
that meets certain other requirements where agreement is made that all future   
transfers will be to taxable domestic corporations in transactions that qualify 
for the same 'safe harbor' provision. Eligibility for this safe harbor requires,
among other things, that the facts and circumstances known to the transferor at 
the time of transfer not indicate to a                                          

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reasonable person that the taxes with respect to the residual interest will not 
be paid, with an unreasonably low cost for the transfer specifically mentioned  
as negating eligibility. See 'Certain Federal Income Tax Consequences --        
Taxation of Owners of REMIC Residual Certificates -- Noneconomic REMIC Residual 
Certificates' in the prospectus.                                                

On May 11, 2004, the Internal Revenue Service issued final regulations  
relating to the federal income tax treatment of 'inducement fees' received by   
transferees of non-economic REMIC residual interests, adopting without change   
the proposed regulations as described in the prospectus. See 'Certain Federal   
Income Tax Consequences -- Taxation of Owners of REMIC Residual                 
Certificates -- General' in the prospectus. These regulations are effective for 
taxable years ending on or after May 11, 2004. Holders of REMIC residual        
certificates should consult their tax advisors regarding the effect of these    
regulations.                                                                    

The Residual Certificateholders may be required to report an amount of  
taxable income with respect to the earlier accrual periods of the REMICs' terms 
that significantly exceeds the amount of cash distributions received by the     
Residual Certificateholders from the REMIC with respect to those periods.       
Consequently, the Residual Certificateholders should have other sources of funds
sufficient to pay any federal income taxes due in the earlier years of the REMIC
as a result of their ownership of Residual Certificates. In addition, the       
required inclusion of this amount of taxable income during the REMICs' earlier  
accrual periods and the deferral of corresponding tax losses or deductions until
later accrual periods or until the ultimate sale or disposition of a Residual   
Certificate (or possibly later under the 'wash sale' rules of Section 1091 of   
the Internal Revenue Code) may cause the Residual Certificateholders' after-tax 
rate of return to be zero or negative even if the Residual Certificateholders'  
pre-tax rate of return is positive. That is, on a present value basis, the      
Residual Certificateholders' resulting tax liabilities could substantially      
exceed the sum of any tax benefits and the amount of any cash distributions on  
the Residual Certificates over their life.                                      

As discussed above, the rules for accrual of OID with respect to certain
classes of certificates are subject to significant complexity and uncertainty.  
Because OID on the certificates will be deducted by the related REMIC in        
determining its taxable income, any changes required by the Internal Revenue    
Service in the application of those rules to the certificates may significantly 
affect the timing of OID deductions to the related REMIC and therefore the      
amount of the related REMIC's taxable income allocable to holders of the        
Residual Certificates.                                                          

Purchasers of the Residual Certificates are strongly advised to consult 
their own tax advisors as to the economic and tax consequences of investment in 
the Residual Certificates.                                                      

For further information regarding the federal income tax consequences of
investing in the Residual Certificates, see 'Yield and Prepayment               
Considerations -- Additional Yield Considerations Applicable Solely to the      
Residual Certificates' in this prospectus supplement and 'Certain Federal Income
Tax Consequences -- Taxation of Owners of REMIC Residual Certificates' in the   
prospectus.                                                                     

 An individual, trust or estate that holds (whether directly or indirectly
through certain pass-through entities) a Residual Certificate may have          
significant additional gross income with respect to, but may be subject to      
limitations on the deductibility of, servicing and trustee's fees and other     
administrative expenses properly allocable to the REMICs in computing that      
certificateholder's regular tax liability and will not be able to deduct those  
fees or expenses to any extent in computing that certificateholder's alternative
minimum tax liability. See 'Certain Federal Income Tax Consequences --          
Pass-Through of Servicing Fees' and ' -- Taxation of Owners of REMIC Residual   
Certificates' in the prospectus.                                                

  Washington Mutual Bank will be designated as the 'tax matters persons' for
the Trust as defined in the REMIC Regulations, and in connection therewith will 
be required to hold not less than 0.01% of the Residual Certificates.           

The Internal Revenue Service has issued proposed regulations that, if   
adopted as final regulations, would cause the question of whether a transfer of 
residual interests will be respected for federal income tax purposes to be      
determined in the audits of the transferee and transferor rather than an item to
be determined as a partnership item in the audit of the REMIC's return.         

PENALTY PROTECTION                                                              

 If penalties were asserted against purchasers of the certificates offered
hereunder in respect of their treatment of the certificates for tax purposes,   
the summary of tax considerations contained, and the                            

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opinions stated, herein and in the prospectus may not meet the conditions       
necessary for purchasers' reliance on that summary and those opinions to        
exculpate them from the asserted penalties.                                     

For further information regarding the federal income tax consequences of
investing in the certificates, see 'Certain Federal Income Tax Consequences' in 
the prospectus.                                                                 

CERTAIN LEGAL INVESTMENT ASPECTS

 For purposes of the Secondary Mortgage Market Enhancement Act of 1984, or
SMMEA, the offered certificates, other than the Class B-4, Class B-5,           
Class B-6, Class B-7, Class B-8 and Class B-9 Certificates, will constitute     
'mortgage related securities' when they are issued. These mortgage related      
securities, or SMMEA Certificates, will be legal investments for persons,       
trusts, corporations, partnerships, associations, business trusts and business  
entities (including depository institutions, life insurance companies, and      
pension funds) created pursuant to or existing under the laws of the United     
States, or of any state, whose authorized investments are subject to state      
regulation to the same extent that, under applicable law, obligations issued by 
or guaranteed as to principal and interest by the United States or any agency or
instrumentality of the United States constitute legal investments for those     
entities. Under SMMEA, if a state enacted legislation before October 4, 1991    
specifically limiting the legal investment authority of any type of such        
entities in 'mortgage related securities,' the SMMEA Certificates will          
constitute legal investments for those types of entities only to the extent     
provided by the legislation. Certain states have enacted such legislation.      
Investors should consult their own legal advisors in determining whether and to 
what extent the offered certificates, constitute legal investments for them.    

SMMEA also amended the legal investment authority of federally-chartered
depository institutions as follows: federal savings and loan associations and   
federal savings banks may invest in, sell or otherwise deal with the SMMEA      
Certificates without limitation as to the percentage of their assets represented
by the SMMEA Certificates, federal credit unions may invest in the SMMEA        
Certificates and national banks may purchase the SMMEA Certificates for their   
own accounts without regard to the limitations generally applicable to          
investment securities prescribed by 12 U.S.C. 24 (Seventh), in each case subject
to such regulations as the applicable federal regulatory authority may adopt.   

 Institutions whose investment activities are subject to review by certain
regulatory authorities may be or may become subject to restrictions on          
investment in the offered certificates, which could be retroactively imposed.   
The Federal Financial Institutions Examination Council, the Federal Deposit     
Insurance Corporation, the Office of the Comptroller of the Currency, the Board 
of Governors of the Federal Reserve System, the Office of Thrift Supervision and
the National Credit Union Administration have adopted guidelines, and have      
proposed policies, regarding the suitability of investments in various types of 
derivative mortgage-backed securities, including securities such as the offered 
certificates. In addition, several states have adopted or are considering       
regulations that would prohibit regulated institutions subject to their         
jurisdiction from holding mortgage-backed securities such as the offered        
certificates. When adopted, the regulations could apply to the offered          
certificates retroactively. Investors should consult their own legal advisors in
determining whether and to what extent the offered certificates constitute legal
investments for them.                                                           

There may be other restrictions on the ability of certain investors,    
including depository institutions, either to purchase the offered certificates  
or to purchase the offered certificates representing more than a specified      
percentage of the investor's assets. Investors should consult their own legal   
advisors in determining whether and to what extent the offered certificates     
constitute legal investments for them.                                          

ERISA CONSIDERATIONS

   ERISA and Section 4975 of the Internal Revenue Code contain provisions that
may affect a fiduciary of an employee benefit plan or other plan or arrangement,
such as an individual retirement account. Plans, insurance companies or other   
persons investing Plan Assets (see 'ERISA Considerations -- Plan Asset          
Regulation' in the prospectus) should carefully review with their legal counsel 
whether owning offered certificates is permitted under ERISA or Section 4975 of 
the Internal Revenue Code. The Underwriter's Exemption or the WCC Exemption, as 
described under 'ERISA Considerations -- Underwriter's Exemption and WCC        
Exemption' in the prospectus, may provide an exemption from restrictions imposed
by ERISA or Section 4975 of the Internal Revenue Code and may permit a Plan to  
own, or Plan Assets to be used to purchase, the offered certificates other than 
the Residual Certificates. However, both the Underwriter's                      

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Exemption and the WCC Exemption contain several conditions, including the       
requirement that an affected Plan must be an 'accredited investor' as defined in
Rule 501(a)(1) of Regulation D of the Securities and Exchange Commission under  
the Securities Act of 1933, as amended. In addition, in order to                
assure the inapplicability of certain restrictions imposed by Section 406(b)(1) 
and (2) of ERISA and Section 4975(c)(1)(E) of the Code in connection with the   
initial issuance of the certificates, each Plan or person using Plan Assets of  
any Plan that acquires offered certificates from the underwriters named in this 
prospectus supplement or from Washington Mutual Bank or any of its affiliates   
will be deemed to represent and warrant that (i) no person who has discretionary
authority or renders investment advice with respect to such acquisition of such 
offered certificates (and no affiliate of such person) is a mortgagor with      
respect to more than 5% of the mortgage loans, (ii) such Plan's investment in   
any class of offered certificates does not and will exceed 25% of all of the    
offered certificates of that class at the time such investment is made, and     
(iii) immediately after such investment is made, no more than 25% of the assets 
of such Plan is invested in securities representing an interest in a trust or   
other issuer containing assets sold or serviced by the same entity (provided    
that an entity will not be considered to service assets contained in a trust or 
other issuer if it is merely a subservicer with respect to such trust or        
issuer).                                                                        

    The Underwriter's Exemption, the WCC Exemption or any similar exemption that
might be available, will likely not apply to the purchase, sale or holding of   
the Residual Certificates. Therefore, the trustee will not register transfers of
the Residual Certificates to a Plan, a trustee or other person acting on behalf 
of any Plan or any other person using Plan Assets to purchase the Residual      
Certificates without first receiving an opinion of counsel. The opinion of      
counsel must:                                                                   

  be satisfactory to Washington Mutual Mortgage Securities
Corp. and the trustee;                                

not be at the expense of Washington Mutual Mortgage   
    Securities Corp., the trustee, the Delaware trustee or the
servicer; and                                         

 conclude that the purchase of the certificates by or on
behalf of the Plan:                                   

is permissible under applicable law;          

          will not constitute or result in a non-exempt prohibited
         transaction under ERISA or Section 4975 of the Internal
Revenue Code; and                             

        will not subject Washington Mutual Mortgage Securities
             Corp., the trustee, the Delaware trustee or the servicer to
       any obligation in addition to those undertaken in the
pooling agreement.                            

Pursuant to the Underwriter's Exemption or the WCC Exemption, Plans may 
purchase and hold subordinate certificates such as the Senior Subordinate       
Certificates if they are rated 'BBB' or better at the time of purchase. See     
'ERISA Considerations -- Underwriter's Exemption and WCC Exemption' in the      
prospectus. A Plan, or other purchaser acting on its behalf or with Plan Assets,
that purchases the Senior Subordinate Certificates will be deemed to have       
represented that:                                                               

     the rating condition was satisfied at the time of purchase;
or                                                    

the following conditions are satisfied:               

it is an insurance company;                   

              the source of funds used to acquire or hold the certificates
           is an 'insurance company general account' as that term is
defined in PTCE 95-60; and                    

              the conditions in Sections I and III of PTCE 95-60 have been
satisfied.                                    

  The pooling and servicing agreement will require that if neither condition
is satisfied the Plan, or other purchaser acting on its behalf or with Plan     
Assets, will:                                                                   

indemnify and hold harmless Washington Mutual Mortgage
  Securities Corp., the trustee, the Delaware trustee, the
   servicer, the underwriters and the Trust from and against
     all liabilities, claims, costs or expenses incurred by them
as a result of the purchase; and                      

   be disregarded as purchaser and the immediately preceding
      permitted beneficial owner will be treated as the beneficial
owner of that certificate.                            

Any fiduciary or other investor of Plan Assets that proposes to own the 
offered certificates on behalf of or with Plan Assets of any Plan should consult
with legal counsel about: (i) whether the specific and                          

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general conditions and the other requirements in the Underwriter's Exemption or 
the WCC Exemption would be satisfied, or whether any other prohibited           
transaction exemption would apply, and (ii) the application of the general      
fiduciary responsibility provisions of ERISA and the prohibited transaction     
provisions of ERISA and Section 4975 of the Internal Revenue Code to the        
proposed investment. See 'ERISA Considerations' in the prospectus.              

 Neither Washington Mutual Mortgage Securities Corp. nor Washington Mutual
Bank makes any representation that the sale of any of the offered certificates  
to a Plan or other purchaser acting on its behalf meets any relevant legal      
requirement for investments by Plans generally or any particular Plan, or that  
the investment is appropriate for Plans generally or any particular Plan.       

METHOD OF DISTRIBUTION

Washington Mutual Mortgage Securities Corp. has agreed to sell to the   
underwriters, and the underwriters have agreed to purchase, all of the offered  
certificates (other than the 0.01% percentage interest of the Class R           
Certificates that Washington Mutual Bank will purchase) in the principal amounts
(or approximate notional amount, in the case of the Class X Certificates) set   
forth below.                                                                    

                                                        [Enlarge/Download Table]

                                                CLASS A-1A    CLASS A-1B1   CLASS A-1B2   CLASS A-1B3 
                 UNDERWRITER                   CERTIFICATES   CERTIFICATES  CERTIFICATES  CERTIFICATES
                 -----------                   ------------   ------------  ------------  ------------
                                                                                                      
WaMu Capital Corp............................ $1,045,789,000  $120,231,000  $48,450,000   $267,064,000
Greenwich Capital Markets, Inc...............    697,193,000    80,154,000   32,300,000    178,043,000
                                              --------------  ------------  -----------   ------------
    Total.................................... $1,742,982,000  $200,385,000  $80,750,000   $445,107,000
                                              --------------  ------------  -----------   ------------
                                              --------------  ------------  -----------   ------------

                                                        [Enlarge/Download Table]

                                              CLASS A-1C1   CLASS A-1C2   CLASS A-1C3   CLASS A-1C4 
                 UNDERWRITER                  CERTIFICATES  CERTIFICATES  CERTIFICATES  CERTIFICATES
                 -----------                  ------------  ------------  ------------  ------------
                                                                                                    
WaMu Capital Corp............................ $101,163,000  $ 62,959,000  $ 66,049,000  $31,276,000 
Greenwich Capital Markets, Inc...............   67,442,000    41,973,000    44,033,000   20,851,000 
                                              ------------  ------------  ------------  ----------- 
    Total.................................... $168,605,000  $104,932,000  $110,082,000  $52,127,000 
                                              ------------  ------------  ------------  ----------- 
                                              ------------  ------------  ------------  ----------- 

                                                        [Enlarge/Download Table]

                                                 CLASS X       CLASS B-1     CLASS B-2     CLASS B-3  
                 UNDERWRITER                   CERTIFICATES   CERTIFICATES  CERTIFICATES  CERTIFICATES
                 -----------                   ------------   ------------  ------------  ------------
                                                                                                      
WaMu Capital Corp............................ $           --  $37,453,000   $26,889,000   $13,444,000 
Greenwich Capital Markets, Inc...............  3,201,069,294   24,968,000    17,926,000     8,963,000 
                                              --------------  -----------   -----------   ----------- 
    Total.................................... $3,201,069,294  $64,421,000   $44,815,000   $22,407,000 
                                              --------------  -----------   -----------   ----------- 
                                              --------------  -----------   -----------   ----------- 

                                                        [Enlarge/Download Table]

                                               CLASS B-4     CLASS B-5     CLASS B-6     CLASS B-7  
                 UNDERWRITER                  CERTIFICATES  CERTIFICATES  CERTIFICATES  CERTIFICATES
                 -----------                  ------------  ------------  ------------  ------------
                                                                                                    
WaMu Capital Corp............................ $13,444,000   $11,524,000   $10,564,000   $ 6,722,000 
Greenwich Capital Markets, Inc...............   8,963,000     7,682,000     7,042,000     4,482,000 
                                              -----------   -----------   -----------   ----------- 
    Total.................................... $22,407,000   $19,206,000   $17,606,000   $11,204,000 
                                              -----------   -----------   -----------   ----------- 
                                              -----------   -----------   -----------   ----------- 

                                                        [Enlarge/Download Table]

                                               CLASS B-8     CLASS B-9      CLASS R   
                 UNDERWRITER                  CERTIFICATES  CERTIFICATES  CERTIFICATES
                 -----------                  ------------  ------------  ------------
                                                                                      
WaMu Capital Corp............................  $5,762,000   $ 7,682,000       $100    
Greenwich Capital Markets, Inc...............   3,841,000     5,122,000         --    
                                               ----------   -----------       ----    
    Total....................................  $9,603,000   $12,804,000       $100    
                                               ----------   -----------       ----    
                                               ----------   -----------       ----    

An underwriting agreement between Washington Mutual Mortgage Securities 
Corp. and the underwriters governs the sale of the offered certificates. The    
aggregate proceeds (excluding accrued interest) to Washington Mutual Mortgage   
Securities Corp. from the sale of the offered certificates, before deducting    
expenses estimated to be $600,000, will be approximately 101.58% of the initial 
aggregate principal balance of the offered certificates. Under the underwriting 
agreement, the underwriters have agreed to take and pay for all of the offered  
certificates, if any are taken. The underwriters will distribute the offered    
certificates from time to time in negotiated transactions or otherwise at       
varying prices to be                                                            

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determined at the time of sale. The difference between the purchase price for   
the offered certificates paid to Washington Mutual Mortgage Securities Corp. and
the proceeds from the sale of the offered certificates realized by the          
underwriters will constitute underwriting discounts and commissions.            

  WaMu Capital Corp. is a wholly owned subsidiary of Washington Mutual Bank.

Washington Mutual Mortgage Securities Corp. has agreed to indemnify the 
underwriters against some civil liabilities, including liabilities under the    
Securities Act of 1933.                                                         

LEGAL MATTERS 

   Washington Mutual Mortgage Securities Corp.'s counsel, Orrick, Herrington &
Sutcliffe LLP, San Francisco, California, and its Delaware counsel, Richards,   
Layton & Finger, P.A., Wilmington, Delaware, will deliver legal opinions        
required by the underwriting agreement. McKee Nelson LLP, New York, New York,   
will pass upon certain legal matters on behalf of the underwriters.             

CERTIFICATE RATINGS 

It is a condition to the issuance of the offered certificates that they 
receive the ratings from S&P and Moody's indicated:                             

                                                                [Download Table]

                              RATING AGENCY   
                            ------------------
CLASS                         S&P      MOODY'S
-----                         ---      -------
                                              
A-1A......................    AAA       Aaa   
A-1B1.....................    AAA       Aaa   
A-1B2.....................    AAA       Aaa   
A-1B3.....................    AAA       Aaa   
A-1C1.....................    AAA       Aaa   
A-1C2.....................    AAA       Aaa   
A-1C3.....................    AAA       Aaa   
X.........................    AAA       Aaa   
B-1.......................    AA+       Aa1   
B-2.......................     AA       Aa2   
B-3.......................     AA-      Aa3   
B-4.......................     A+       A1    
B-5.......................     A        A2    
B-6.......................     A-       A3    
B-7.......................    BBB+     Baa1   
B-8.......................    BBB      Baa2   
B-9.......................    BBB-     Baa3   
R.........................    AAA       Aaa   

 A security rating is not a recommendation to buy, sell or hold securities
and may be subject to revision or withdrawal at any time by the assigning rating
agency. Each security rating should be evaluated independently of any other     
security rating.                                                                

The ratings assigned to this issue do not constitute a recommendation to
purchase or sell these securities. Rather, they are an indication of the        
likelihood of the payment of principal and interest as set forth in the         
transaction documentation. The ratings do not address the effect on the         
certificates' yield attributable to prepayments or recoveries on the underlying 
mortgage loans. Additionally, the ratings on the Class R Certificates address   
only the return of the Class R Principal Balance and interest on that balance at
the stated rate.                                                                

The ratings on the offered certificates address the likelihood of the   
receipt by certificateholders of all distributions with respect to the          
underlying mortgage loans to which they are entitled. The ratings do not        
represent any assessment of the likelihood that the rate of principal           
prepayments by mortgagors might differ from those originally anticipated. As a  
result of differences in the rate of principal prepayments, certificateholders  
might suffer a lower than anticipated yield to maturity. See 'Risk Factors' and 
'Yield and Prepayment Considerations' in this prospectus supplement.            

 Washington Mutual Mortgage Securities Corp. has not requested a rating on
the offered certificates by any rating agency other than S&P and Moody's.       
However, there can be no assurance as to whether any other rating agency will   
rate the offered certificates, or, if it does, what rating would be assigned by 
any other rating agency. A rating on the offered certificates by another rating 
agency, if assigned at all, may be lower than the rating assigned to the offered
certificates by S&P or Moody's.                                                 

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                                                                   APPENDIX A'D'

PERCENT OF INITIAL CLASS PRINCIPAL BALANCE OUTSTANDING
AT VARIOUS PERCENTAGES OF THE CONSTANT PREPAYMENT RATE

                                                        [Enlarge/Download Table]

                            CLASS A-1A, CLASS A-1B3 AND                                                                          
                                    CLASS A-1C4                        CLASS A-1B1                        CLASS A-1B2            
DISTRIBUTION              --------------------------------   --------------------------------  ----------------------------------
DATE                      12%    15%    25%    30%    40%    12%    15%    25%    30%    40%    12%     15%    25%    30%    40% 
----                      ---    ---    ---    ---    ---    ---    ---    ---    ---    ---    ---     ---    ---    ---    --- 
                                                                                                                                 
Initial Percentages.....  100    100    100    100    100    100    100    100    100    100     100     100   100    100    100 
August 25, 2006.........   86     82     71     66     55     80     75     60     52     37     100     100   100    100    100 
August 25, 2007.........   73     67     50     43     30     62     54     30     19      2     100     100   100    100    100 
August 25, 2008.........   62     55     35     28     16     47     37      9      0      0     100     100   100     97     56 
August 25, 2009.........   53     44     26     19     10     33     22      0      0      0     100     100    91     67     33 
August 25, 2010.........   44     37     19     13      6     22     11      0      0      0     100     100    67     46     20 
August 25, 2011.........   38     31     14      9      3     12      3      0      0      0     100     100    49     32     12 
August 25, 2012.........   32     25     10      6      2      5      0      0      0      0     100      88    36     22      7 
August 25, 2013.........   28     21      8      4      1      0      0      0      0      0      97      73    27     15      4 
August 25, 2014.........   24     17      6      3      1      0      0      0      0      0      83      61    19     10      2 
August 25, 2015.........   20     14      4      2      *      0      0      0      0      0      71      50    14      7      1 
August 25, 2016.........   18     12      3      1      *      0      0      0      0      0      61      42    10      5      1 
August 25, 2017.........   15     10      2      1      *      0      0      0      0      0      52      34     7      3      * 
August 25, 2018.........   13      8      2      1      *      0      0      0      0      0      44      28     5      2      * 
August 25, 2019.........   11      7      1      *      *      0      0      0      0      0      37      23     4      1      * 
August 25, 2020.........    9      5      1      *      *      0      0      0      0      0      32      19     3      1      * 
August 25, 2021.........    8      4      1      *      *      0      0      0      0      0      27      15     2      1      * 
August 25, 2022.........    6      4      *      *      *      0      0      0      0      0      22      12     1      *      * 
August 25, 2023.........    5      3      *      *      *      0      0      0      0      0      18      10     1      *      * 
August 25, 2024.........    4      2      *      *      *      0      0      0      0      0      15       8     1      *      * 
August 25, 2025.........    4      2      *      *      *      0      0      0      0      0      13       6     1      *      * 
August 25, 2026.........    3      1      *      *      *      0      0      0      0      0      10       5     *      *      * 
August 25, 2027.........    2      1      *      *      *      0      0      0      0      0       8       4     *      *      * 
August 25, 2028.........    2      1      *      *      *      0      0      0      0      0       6       3     *      *      * 
August 25, 2029.........    1      1      *      *      *      0      0      0      0      0       5       2     *      *      * 
August 25, 2030.........    1      *      *      *      *      0      0      0      0      0       4       2     *      *      * 
August 25, 2031.........    1      *      *      *      *      0      0      0      0      0       3       1     *      *      * 
August 25, 2032.........    1      *      *      *      *      0      0      0      0      0       2       1     *      *      * 
August 25, 2033.........    *      *      *      *      *      0      0      0      0      0       1       *     *      *      * 
August 25, 2034.........    *      *      *      *      *      0      0      0      0      0       1       *     *      *      * 
August 25, 2035.........    *      *      *      *      *      0      0      0      0      0       *       *     *      *      * 
August 25, 2036.........    *      *      *      *      *      0      0      0      0      0       *       *     *      *      * 
August 25, 2037.........    *      *      *      *      *      0      0      0      0      0       *       *     *      *      * 
August 25, 2038.........    *      *      *      *      *      0      0      0      0      0       *       *     *      *      * 
August 25, 2039.........    *      *      *      *      *      0      0      0      0      0       *       *     *      *      * 
August 25, 2040.........    *      *      *      *      *      0      0      0      0      0       *       *     *      *      * 
August 25, 2041.........    *      *      *      *      *      0      0      0      0      0       *       *     *      *      * 
August 25, 2042.........    *      *      *      *      *      0      0      0      0      0       *       *     *      *      * 
August 25, 2043.........    *      *      *      *      *      0      0      0      0      0       *       *     *      *      * 
August 25, 2044.........    *      *      *      *      *      0      0      0      0      0       *       *     *      *      * 
August 25, 2045.........    0      0      0      0      0      0      0      0      0      0       0       0     0      0      0 
Weighted Average Life                                                                                                            
 (in years)(1).......... 6.16   5.09   3.06   2.49   1.74   3.14   2.54   1.50   1.22   0.88   13.68   11.43  6.95   5.62   3.89 
Weighted Average Life to                                                                                                         
 the Clean-Up Call                                                                                                               
 Option Date (in                                                                                                                 
 years)(1)(2)........... 5.74   4.70   2.80   2.27   1.60   3.14   2.54   1.50   1.22   0.88   12.20   10.05  6.02   4.86   3.40 

---------                                                                       
'D' The following tables have been prepared based on the assumptions described  
 in this prospectus supplement under 'Yield and Prepayment Considerations'
   (including the assumptions regarding the characteristics and performance of
the mortgage loans which differ from their actual characteristics and   
performance) and should be read in conjunction with that section.       

 * Indicates an amount above zero and less than 0.5% of the original principal
balance outstanding.                                                    

(1) The weighted average life of any class of certificates is determined by (i) 
 multiplying the assumed net reduction, if any, in the principal amount on
   each Distribution Date on such class of certificates by the number of years
from the date of issuance of the certificate to the related Distribution
   Date, (ii) summing the results, and (iii) dividing the sum by the aggregate
 amount of the assumed net reductions in principal amount on such class of
certificates.                                                           

(2) The weighted average lives to the Clean-Up Call Option Date have been       
prepared based on an additional assumption that the Class A-1A,         
Class A-1B1, Class A-1B2, Class A-1B3, Class A-1C1, Class A-1C2,        
 Class A-1C3, Class A-1C4, Class A-2A1, Class A-2A2, Class B-1, Class B-2,
Class B-3, Class B-4, Class B-5, Class B-6, Class B-7, Class B-8 and    
Class B-9 Certificates are sold immediately on the Clean-Up Call Option 
Date.                                                                   

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PERCENT OF INITIAL CLASS PRINCIPAL BALANCE OUTSTANDING
AT VARIOUS PERCENTAGES OF THE CONSTANT PREPAYMENT RATE

                                                        [Enlarge/Download Table]


                                     CLASS A-1C1                         CLASS A-1C2               CLASS A-1C3 
DISTRIBUTION              ---------------------------------   ----------------------------------  -------------
DATE                       12%    15%    25%    30%    40%     12%     15%    25%    30%    40%    12%     15% 
----                       ---    ---    ---    ---    ---     ---     ---    ---    ---    ---    ---     --- 
                                                                                                               
Initial Percentages.....    100   100    100    100    100      100     100   100    100    100     100     100
August 25, 2006.........     67    60     35     23      0      100     100   100    100     97     100     100
August 25, 2007.........     39    26      0      0      0      100     100    79     51      5     100     100
August 25, 2008.........     14     0      0      0      0      100      96    25      0      0     100     100
August 25, 2009.........      0     0      0      0      0       87      58     0      0      0     100     100
August 25, 2010.........      0     0      0      0      0       57      29     0      0      0     100     100
August 25, 2011.........      0     0      0      0      0       33       7     0      0      0     100     100
August 25, 2012.........      0     0      0      0      0       14       0     0      0      0     100      89
August 25, 2013.........      0     0      0      0      0        0       0     0      0      0      97      74
August 25, 2014.........      0     0      0      0      0        0       0     0      0      0      83      61
August 25, 2015.........      0     0      0      0      0        0       0     0      0      0      71      50
August 25, 2016.........      0     0      0      0      0        0       0     0      0      0      61      42
August 25, 2017.........      0     0      0      0      0        0       0     0      0      0      52      34
August 25, 2018.........      0     0      0      0      0        0       0     0      0      0      44      28
August 25, 2019.........      0     0      0      0      0        0       0     0      0      0      37      23
August 25, 2020.........      0     0      0      0      0        0       0     0      0      0      32      19
August 25, 2021.........      0     0      0      0      0        0       0     0      0      0      27      15
August 25, 2022.........      0     0      0      0      0        0       0     0      0      0      22      12
August 25, 2023.........      0     0      0      0      0        0       0     0      0      0      19      10
August 25, 2024.........      0     0      0      0      0        0       0     0      0      0      15       8
August 25, 2025.........      0     0      0      0      0        0       0     0      0      0      13       6
August 25, 2026.........      0     0      0      0      0        0       0     0      0      0      10       5
August 25, 2027.........      0     0      0      0      0        0       0     0      0      0       8       4
August 25, 2028.........      0     0      0      0      0        0       0     0      0      0       6       3
August 25, 2029.........      0     0      0      0      0        0       0     0      0      0       5       2
August 25, 2030.........      0     0      0      0      0        0       0     0      0      0       4       2
August 25, 2031.........      0     0      0      0      0        0       0     0      0      0       3       1
August 25, 2032.........      0     0      0      0      0        0       0     0      0      0       2       1
August 25, 2033.........      0     0      0      0      0        0       0     0      0      0       1       *
August 25, 2034.........      0     0      0      0      0        0       0     0      0      0       1       *
August 25, 2035.........      0     0      0      0      0        0       0     0      0      0       *       *
August 25, 2036.........      0     0      0      0      0        0       0     0      0      0       *       *
August 25, 2037.........      0     0      0      0      0        0       0     0      0      0       *       *
August 25, 2038.........      0     0      0      0      0        0       0     0      0      0       *       *
August 25, 2039.........      0     0      0      0      0        0       0     0      0      0       *       *
August 25, 2040.........      0     0      0      0      0        0       0     0      0      0       *       *
August 25, 2041.........      0     0      0      0      0        0       0     0      0      0       *       *
August 25, 2042.........      0     0      0      0      0        0       0     0      0      0       *       *
August 25, 2043.........      0     0      0      0      0        0       0     0      0      0       *       *
August 25, 2044.........      0     0      0      0      0        0       0     0      0      0       *       *
August 25, 2045.........      0     0      0      0      0        0       0     0      0      0       0       0
Weighted Average Life                                                                                          
 (in years)(1)..........   1.70  1.37   0.82   0.67   0.49     5.45    4.41  2.59   2.11   1.50   13.68   11.44
Weighted Average Life to                                                                                       
 the Clean-Up Call                                                                                             
 Option Date (in                                                                                               
 years)(1)(2)...........   1.70  1.37   0.82   0.67   0.49     5.45    4.41  2.59   2.11   1.50   12.21   10.05


                                                CLASS B-1, CLASS B-2, CLASS B-3,                               
                                                CLASS B-4, CLASS B-5, CLASS B-6,                               
                             CLASS A-1C3       CLASS B-7, CLASS B-8 AND CLASS B-9                              
DISTRIBUTION              ------------------   ----------------------------------                              
DATE                      25%    30%    40%     12%     15%    25%    30%    40%                               
----                      ---    ---    ---     ---     ---    ---    ---    ---                               
                                                                                                               
Initial Percentages.....  100    100    100      100     100   100    100     100                              
August 25, 2006.........  100    100    100       99      99    99     99      99                              
August 25, 2007.........  100    100    100       97      97    97     97      84                              
August 25, 2008.........  100     97     57       96      96    88     80      64                              
August 25, 2009.........   91     67     33       94      94    65     55      38                              
August 25, 2010.........   67     46     20       92      83    48     38      22                              
August 25, 2011.........   49     32     12       85      69    35     26      13                              
August 25, 2012.........   36     22      7       73      57    26     18       8                              
August 25, 2013.........   27     15      4       63      48    19     12       5                              
August 25, 2014.........   19     10      2       54      39    14      8       3                              
August 25, 2015.........   14      7      1       46      33    10      6       2                              
August 25, 2016.........   10      5      1       39      27     7      4       1                              
August 25, 2017.........    7      3      *       34      22     5      3       1                              
August 25, 2018.........    5      2      *       29      18     4      2       *                              
August 25, 2019.........    4      1      *       24      15     3      1       *                              
August 25, 2020.........    3      1      *       20      12     2      1       *                              
August 25, 2021.........    2      1      *       17      10     1      1       *                              
August 25, 2022.........    1      *      *       14       8     1      *       *                              
August 25, 2023.........    1      *      *       12       6     1      *       *                              
August 25, 2024.........    1      *      *       10       5     1      *       *                              
August 25, 2025.........    1      *      *        8       4     *      *       *                              
August 25, 2026.........    *      *      *        7       3     *      *       *                              
August 25, 2027.........    *      *      *        5       2     *      *       *                              
August 25, 2028.........    *      *      *        4       2     *      *       *                              
August 25, 2029.........    *      *      *        3       1     *      *       *                              
August 25, 2030.........    *      *      *        2       1     *      *       *                              
August 25, 2031.........    *      *      *        2       1     *      *       *                              
August 25, 2032.........    *      *      *        1       *     *      *       *                              
August 25, 2033.........    *      *      *        1       *     *      *       *                              
August 25, 2034.........    *      *      *        *       *     *      *       *                              
August 25, 2035.........    *      *      *        *       *     *      *       *                              
August 25, 2036.........    *      *      *        *       *     *      *       *                              
August 25, 2037.........    *      *      *        *       *     *      *       *                              
August 25, 2038.........    *      *      *        *       *     *      *       *                              
August 25, 2039.........    *      *      *        *       *     *      *       *                              
August 25, 2040.........    *      *      *        *       *     *      *       *                              
August 25, 2041.........    *      *      *        *       *     *      *       *                              
August 25, 2042.........    *      *      *        *       *     *      *       *                              
August 25, 2043.........    *      *      *        *       *     *      *       *                              
August 25, 2044.........    *      *      *        *       *     *      *       *                              
August 25, 2045.........    0      0      0        0       0     0      0       0                              
Weighted Average Life                                                                                          
 (in years)(1).......... 6.95   5.62   3.89    10.87    9.08  5.80   5.02    3.92                              
Weighted Average Life to                                                                                       
 the Clean-Up Call                                                                                             
 Option Date (in                                                                                               
 years)(1)(2)........... 6.02   4.86   3.40     9.92    8.19  5.13   4.39    3.36                              

---------                                                                       
'D' The following tables have been prepared based on the assumptions described  
 in this prospectus supplement under 'Yield and Prepayment Considerations'
   (including the assumptions regarding the characteristics and performance of
the mortgage loans which differ from their actual characteristics and   
performance) and should be read in conjunction with that section.       

 * Indicates an amount above zero and less than 0.5% of the original principal
balance outstanding.                                                    

(1) The weighted average life of any class of certificates is determined by (i) 
 multiplying the assumed net reduction, if any, in the principal amount on
   each Distribution Date on such class of certificates by the number of years
from the date of issuance of the certificate to the related Distribution
   Date, (ii) summing the results, and (iii) dividing the sum by the aggregate
 amount of the assumed net reductions in principal amount on such class of
certificates.                                                           

(2) The weighted average lives to the Clean-Up Call Option Date have been       
prepared based on an additional assumption that the Class A-1A,         
Class A-1B1, Class A-1B2, Class A-1B3, Class A-1C1, Class A-1C2,        
 Class A-1C3, Class A-1C4, Class A-2A1, Class A-2A2, Class B-1, Class B-2,
Class B-3, Class B-4, Class B-5, Class B-6, Class B-7, Class B-8 and    
Class B-9 Certificates are sold immediately on the Clean-Up Call Option 
Date.                                                                   

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                                                                      APPENDIX B

                                                                [Download Table]

            MORTGAGE INTEREST RATES OF THE MORTGAGE LOANS             
----------------------------------------------------------------------
                                        AGGREGATE         PERCENTAGE  
                                        PRINCIPAL           OF THE    
                                     BALANCE OF THE       AGGREGATE   
                        NUMBER OF       MORTGAGE          PRINCIPAL   
  MORTGAGE INTEREST     MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
       RATE (%)           LOANS       CUT-OFF DATE      MORTGAGE LOANS
----------------------------------------------------------------------
                                                                      
4.437.................        1     $      823,494.41         0.03%   
4.487.................       16         11,515,051.16         0.36    
4.507.................        2          2,996,277.29         0.09    
4.537.................       40         27,476,484.71         0.86    
4.587.................       10          6,716,444.78         0.21    
4.607.................        3          2,935,574.67         0.09    
4.627.................        1            471,417.58         0.01    
4.637.................       51         36,917,277.82         1.15    
4.657.................        1          1,278,156.79         0.04    
4.677.................        1            823,045.07         0.03    
4.687.................       68         43,688,332.83         1.36    
4.707.................        1            933,683.95         0.03    
4.737.................      100         65,261,685.15         2.04    
4.747.................        1          1,123,016.56         0.04    
4.757.................        5          2,842,486.83         0.09    
4.777.................        1            897,686.99         0.03    
4.787.................      298        182,777,055.00         5.71    
4.807.................        7          4,972,313.59         0.16    
4.827.................        1            646,839.67         0.02    
4.837.................       29         16,421,003.88         0.51    
4.857.................       27         16,290,018.26         0.51    
4.877.................        4          2,343,175.79         0.07    
4.887.................      656        420,324,183.65        13.13    
4.902.................        1            484,088.48         0.02    
4.907.................        2          1,395,284.31         0.04    
4.908.................        1            523,821.44         0.02    
4.927.................        6          3,998,020.88         0.12    
4.937.................      186        112,717,619.23         3.52    
4.947.................        2          2,704,771.27         0.08    
4.957.................       43         27,682,262.91         0.86    
4.987.................      197        128,240,314.07         4.01    
4.997.................        2          1,564,657.53         0.05    
5.007.................       14          8,906,688.36         0.28    
5.027.................       19         12,429,792.51         0.39    
5.032.................        1            846,266.57         0.03    
5.037.................      486        304,839,561.42         9.52    
5.039.................        1            638,533.86         0.02    
5.057.................       13          8,290,747.61         0.26    
5.062.................        1          1,079,118.80         0.03    
5.077.................        7          3,661,333.68         0.11    
5.087.................      313        176,658,589.59         5.52    
5.097.................       10          7,652,288.37         0.24    
5.107.................       47         28,645,583.99         0.89    
5.125.................        1          1,119,876.18         0.03    
5.127.................       17         10,057,074.30         0.31    
5.137.................     1125        670,661,211.96        20.95    
5.144.................        1            444,359.20         0.01    
5.147.................        1            533,803.86         0.02    
5.157.................       28         16,209,805.28         0.51    
5.167.................        1          1,500,753.89         0.05    
5.172.................        1            893,738.31         0.03    
5.177.................       14          9,275,529.47         0.29    
5.187.................       97         67,239,368.45         2.10    
5.197.................        5          4,301,855.65         0.13    
5.207.................       58         35,670,082.73         1.11    

                                                                [Download Table]

      MORTGAGE INTEREST RATES OF THE MORTGAGE LOANS -- CONTINUED      
----------------------------------------------------------------------
                                        AGGREGATE         PERCENTAGE  
                                        PRINCIPAL           OF THE    
                                     BALANCE OF THE       AGGREGATE   
                        NUMBER OF       MORTGAGE          PRINCIPAL   
  MORTGAGE INTEREST     MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
       RATE (%)           LOANS       CUT-OFF DATE      MORTGAGE LOANS
----------------------------------------------------------------------
                                                                      
5.212.................        1     $    1,483,959.80         0.05%   
5.227.................       32         21,110,841.15         0.66    
5.232.................        1            623,930.61         0.02    
5.237.................       48         33,687,411.11         1.05    
5.241.................        1            419,037.84         0.01    
5.247.................        4          3,581,106.03         0.11    
5.252.................        1            473,061.88         0.01    
5.257.................        7          5,120,485.42         0.16    
5.262.................        2          1,971,331.47         0.06    
5.277.................       63         39,223,290.36         1.23    
5.287.................      113         87,270,505.32         2.73    
5.297.................       10          6,262,435.60         0.20    
5.307.................        3          1,525,248.45         0.05    
5.312.................        2          1,795,784.60         0.06    
5.317.................        4          4,248,597.00         0.13    
5.327.................        5          4,483,709.72         0.14    
5.337.................      120         64,630,953.06         2.02    
5.347.................       24         19,526,061.14         0.61    
5.357.................        5          7,410,941.27         0.23    
5.377.................      165        107,901,452.08         3.37    
5.382.................        7          6,180,313.39         0.19    
5.387.................      116         64,010,093.15         2.00    
5.397.................        1            674,826.23         0.02    
5.407.................       10          7,476,920.36         0.23    
5.417.................        7          3,820,271.57         0.12    
5.427.................        3          1,464,383.04         0.05    
5.437.................       19         12,006,489.80         0.38    
5.447.................       14          8,219,379.94         0.26    
5.457.................       15         11,065,476.57         0.35    
5.467.................        3          1,581,167.89         0.05    
5.477.................        1            499,826.20         0.02    
5.482.................        3          1,865,198.40         0.06    
5.487.................       45         29,396,226.35         0.92    
5.497.................        2          3,504,073.40         0.11    
5.507.................        1            698,434.28         0.02    
5.517.................        6          4,869,003.04         0.15    
5.527.................        5          5,416,097.63         0.17    
5.537.................       16         11,245,129.32         0.35    
5.547.................        1            520,895.16         0.02    
5.552.................        1            374,589.85         0.01    
5.557.................       15         11,203,094.30         0.35    
5.567.................        8          5,391,820.67         0.17    
5.587.................       21         13,058,143.50         0.41    
5.597.................        3          3,719,771.30         0.12    
5.607.................        4          2,191,070.93         0.07    
5.617.................        1            404,072.21         0.01    
5.627.................        5          3,220,152.92         0.10    
5.637.................       79         51,586,589.67         1.61    
5.647.................        3          2,657,104.99         0.08    
5.657.................        3          2,911,875.78         0.09    
5.667.................       18         10,173,777.91         0.32    
5.687.................        5          5,571,370.33         0.17    
                          -----     -----------------       ------    
  Total...............    5,077     $3,201,069,294.58       100.00%   
                          -----     -----------------       ------    
                          -----     -----------------       ------    

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                                                                [Download Table]

               PASS-THROUGH RATES OF THE MORTGAGE LOANS               
----------------------------------------------------------------------
                                AGGREGATE                   WEIGHTED  
                                PRINCIPAL       WEIGHTED     AVERAGE  
                             BALANCE OF THE     AVERAGE     SCHEDULED 
                                MORTGAGE        MORTGAGE    REMAINING 
       PASS-THROUGH          LOANS AS OF THE    INTEREST      TERM    
        RATES (%)             CUT-OFF DATE       RATES     (IN MONTHS)
----------------------------------------------------------------------
                                                                      
4.062.....................  $      823,494.41    4.437%        355    
4.112.....................      11,515,051.16    4.487         357    
4.132.....................       2,996,277.29    4.507         417    
4.162.....................      27,476,484.71    4.537         356    
4.212.....................       6,716,444.78    4.587         384    
4.232.....................       2,935,574.67    4.607         476    
4.252.....................         471,417.58    4.627         358    
4.262.....................      36,917,277.82    4.637         360    
4.282.....................       1,278,156.79    4.657         478    
4.302.....................         823,045.07    4.677         356    
4.312.....................      43,688,332.83    4.687         360    
4.332.....................         933,683.95    4.707         356    
4.362.....................      65,261,685.15    4.737         361    
4.372.....................       1,123,016.56    4.747         357    
4.382.....................       2,842,486.83    4.757         398    
4.402.....................         897,686.99    4.777         357    
4.412.....................     182,777,055.00    4.787         357    
4.432.....................       4,972,313.59    4.807         456    
4.452.....................         646,839.67    4.827         356    
4.462.....................      16,421,003.88    4.837         393    
4.482.....................      16,290,018.26    4.857         439    
4.502.....................       2,343,175.79    4.877         422    
4.512.....................     420,324,183.65    4.887         356    
4.527.....................         484,088.48    4.902         358    
4.532.....................       1,395,284.31    4.907         477    
4.533.....................         523,821.44    4.908         477    
4.552.....................       3,998,020.88    4.927         378    
4.562.....................     112,717,619.23    4.937         361    
4.572.....................       2,704,771.27    4.947         354    
4.582.....................      27,682,262.91    4.957         466    
4.612.....................     128,240,314.07    4.987         360    
4.622.....................       1,564,657.53    4.997         357    
4.632.....................       8,906,688.36    5.007         409    
4.652.....................      12,429,792.51    5.027         355    
4.657.....................         846,266.57    5.032         356    
4.662.....................     304,839,561.42    5.037         358    
4.664.....................         638,533.86    5.039         358    
4.682.....................       8,290,747.61    5.057         454    
4.687.....................       1,079,118.80    5.062         356    
4.702.....................       3,661,333.68    5.077         370    
4.712.....................     176,658,589.59    5.087         357    
4.722.....................       7,652,288.37    5.097         366    
4.732.....................      28,645,583.99    5.107         449    
4.750.....................       1,119,876.18    5.125         355    
4.752.....................      10,057,074.30    5.127         356    
4.762.....................     670,661,211.96    5.137         356    
4.769.....................         444,359.20    5.144         478    
4.772.....................         533,803.86    5.147         352    
4.782.....................      16,209,805.28    5.157         391    
4.792.....................       1,500,753.89    5.167         354    
4.797.....................         893,738.31    5.172         357    
4.802.....................       9,275,529.47    5.177         357    
4.812.....................      67,239,368.45    5.187         370    
4.822.....................       4,301,855.65    5.197         389    
4.832.....................      35,670,082.73    5.207         467    
4.837.....................       1,483,959.80    5.212         356    

                                                                [Download Table]

        PASS-THROUGH RATES OF THE MORTGAGE LOANS -- CONTINUED         
----------------------------------------------------------------------
                                AGGREGATE                   WEIGHTED  
                                PRINCIPAL       WEIGHTED     AVERAGE  
                             BALANCE OF THE     AVERAGE     SCHEDULED 
                                MORTGAGE        MORTGAGE    REMAINING 
       PASS-THROUGH          LOANS AS OF THE    INTEREST      TERM    
        RATES (%)             CUT-OFF DATE       RATES     (IN MONTHS)
----------------------------------------------------------------------
                                                                      
4.852.....................  $   21,110,841.15    5.227%        362    
4.857.....................         623,930.61    5.232         356    
4.862.....................      33,687,411.11    5.237         359    
4.866.....................         419,037.84    5.241         358    
4.872.....................       3,581,106.03    5.247         358    
4.877.....................         473,061.88    5.252         350    
4.882.....................       5,120,485.42    5.257         408    
4.887.....................       1,971,331.47    5.262         352    
4.902.....................      39,223,290.36    5.277         360    
4.912.....................      87,270,505.32    5.287         359    
4.922.....................       6,262,435.60    5.297         410    
4.932.....................       1,525,248.45    5.307         387    
4.937.....................       1,795,784.60    5.312         357    
4.942.....................       4,248,597.00    5.317         358    
4.952.....................       4,483,709.72    5.327         358    
4.962.....................      64,630,953.06    5.337         354    
4.972.....................      19,526,061.14    5.347         405    
4.982.....................       7,410,941.27    5.357         464    
5.002.....................     107,901,452.08    5.377         356    
5.007.....................       6,180,313.39    5.382         356    
5.012.....................      64,010,093.15    5.387         363    
5.022.....................         674,826.23    5.397         356    
5.032.....................       7,476,920.36    5.407         386    
5.042.....................       3,820,271.57    5.417         357    
5.052.....................       1,464,383.04    5.427         396    
5.062.....................      12,006,489.80    5.437         364    
5.072.....................       8,219,379.94    5.447         452    
5.082.....................      11,065,476.57    5.457         412    
5.092.....................       1,581,167.89    5.467         356    
5.102.....................         499,826.20    5.477         355    
5.107.....................       1,865,198.40    5.482         355    
5.112.....................      29,396,226.35    5.487         360    
5.122.....................       3,504,073.40    5.497         356    
5.132.....................         698,434.28    5.507         358    
5.142.....................       4,869,003.04    5.517         357    
5.152.....................       5,416,097.63    5.527         356    
5.162.....................      11,245,129.32    5.537         357    
5.172.....................         520,895.16    5.547         476    
5.177.....................         374,589.85    5.552         357    
5.182.....................      11,203,094.30    5.557         392    
5.192.....................       5,391,820.67    5.567         358    
5.212.....................      13,058,143.50    5.587         356    
5.222.....................       3,719,771.30    5.597         396    
5.232.....................       2,191,070.93    5.607         448    
5.242.....................         404,072.21    5.617         358    
5.252.....................       3,220,152.92    5.627         413    
5.262.....................      51,586,589.67    5.637         358    
5.272.....................       2,657,104.99    5.647         355    
5.282.....................       2,911,875.78    5.657         356    
5.292.....................      10,173,777.91    5.667         364    
5.312.....................       5,571,370.33    5.687         357    
                            -----------------    -----         ---    
Total.....................  $3,201,069,294.58    5.079%*       364*   
                            -----------------                         
                            -----------------                         

* Represents a weighted average of the mortgage loans.                          

  As of the Cut-Off Date, the Pass-Through Rate for the mortgage loans loans
is approximately 4.704% per annum.                                              

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            ORIGINAL PRINCIPAL BALANCES OF THE MORTGAGE LOANS            
-------------------------------------------------------------------------
                                         AGGREGATE          PERCENTAGE   
                                         PRINCIPAL            OF THE     
                                      BALANCES OF THE       AGGREGATE    
                         NUMBER OF       MORTGAGE           PRINCIPAL    
   RANGE OF ORIGINAL     MORTGAGE     LOANS AS OF THE     BALANCE OF ALL 
  PRINCIPAL BALANCES       LOANS       CUT-OFF DATE       MORTGAGE LOANS 
-------------------------------------------------------------------------
                                                                         
$  350,001 -   400,000...     735      $ 278,211,153.24          8.69%   
$  400,001 -   450,000...     736        313,400,351.13          9.79    
$  450,001 -   500,000...     704        335,732,302.32         10.49    
$  500,001 -   550,000...     515        269,414,253.42          8.42    
$  550,001 -   600,000...     458        263,342,960.04          8.23    
$  600,001 -   650,000...     414        261,198,941.01          8.16    
$  650,001 -   700,000...     232        156,103,043.94          4.88    
$  700,001 -   750,000...     164        118,809,725.59          3.71    
$  750,001 -   800,000...     157        121,868,840.89          3.81    
$  800,001 -   850,000...     109         89,571,612.61          2.80    
$  850,001 -   900,000...     106         92,787,172.31          2.90    
$  900,001 -   950,000...      77         71,320,117.39          2.23    
$  950,001 - 1,000,000...     185        182,033,054.39          5.69    
$1,000,001 - 1,050,000...      50         51,580,870.07          1.61    
$1,050,001 - 1,100,000...      37         40,075,841.12          1.25    
$1,100,001 - 1,150,000...      36         40,260,463.74          1.26    
$1,150,001 - 1,200,000...      56         65,772,998.04          2.05    
$1,200,001 - 1,250,000...      45         55,252,267.87          1.73    
$1,250,001 - 1,300,000...      40         51,311,062.93          1.60    
$1,300,001 - 1,350,000...      25         33,276,862.60          1.04    
$1,350,001 - 1,400,000...      34         47,166,004.29          1.47    
$1,400,001 - 1,450,000...      19         26,895,178.39          0.84    
$1,450,001 - 1,500,000...      99        147,746,653.13          4.62    
Over $1,500,000..........      44         87,937,564.12          2.75    
                            -----      -----------------        ------   
  Total..................   5,077      $3,201,069,294.58        100.00%  
                            -----      -----------------        ------   
                            -----      -----------------        ------   

   As of the Cut-Off Date, the principal balances of the mortgage loans ranged
from approximately $20,104 to $2,498,141 with an average of approximately       
$630,504.                                                                       

                                                                [Download Table]

           CURRENT LOAN-TO-VALUE RATIOS OF THE MORTGAGE LOANS            
-------------------------------------------------------------------------
                                           AGGREGATE         PERCENTAGE  
                                           PRINCIPAL           OF THE    
                                        BALANCE OF THE       AGGREGATE   
         CURRENT           NUMBER OF       MORTGAGE          PRINCIPAL   
      LOAN-TO-VALUE        MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
        RATIO (%)            LOANS       CUT-OFF DATE      MORTGAGE LOANS
-------------------------------------------------------------------------
                                                                         
60.00 or less............      690     $  498,624,939.15        15.58%   
60.01 - 70.00............    1,090        816,279,169.60        25.50    
70.01 - 75.00............    1,219        736,339,508.67        23.00    
75.01 - 80.00............    1,870      1,044,359,930.80        32.63    
80.01 - 85.00............      137         74,354,699.47         2.32    
85.01 - 90.00............       14          6,670,345.74         0.21    
90.01 - 95.00............       57         24,440,701.15         0.76    
                             -----     -----------------       ------    
  Total..................    5,077     $3,201,069,294.58       100.00%   
                             -----     -----------------       ------    
                             -----     -----------------       ------    

At origination, the weighted average loan-to-value ratio of the mortgage
loans was approximately 70.4%. As of the Cut-Off Date, the weighted average     
loan-to-value ratio of the mortgage loans was approximately 70.1%.              

                                                                [Download Table]

          TYPES OF MORTGAGED PROPERTIES SECURING MORTGAGE LOANS          
-------------------------------------------------------------------------
                                           AGGREGATE         PERCENTAGE  
                                           PRINCIPAL           OF THE    
                                        BALANCE OF THE       AGGREGATE   
                           NUMBER OF       MORTGAGE          PRINCIPAL   
                           MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
      PROPERTY TYPE          LOANS       CUT-OFF DATE      MORTGAGE LOANS
-------------------------------------------------------------------------
                                                                         
Single Family Detached...    4,522     $2,874,507,158.75        89.80%   
Duplex...................       51         33,877,396.55         1.06    
Townhouse................       12          6,315,640.73         0.20    
Condominium..............      479        275,846,365.36         8.62    
Housing Cooperative......       13         10,522,733.19         0.33    
                             -----     -----------------       ------    
  Total..................    5,077     $3,201,069,294.58       100.00%   
                             -----     -----------------       ------    
                             -----     -----------------       ------    

                                                                [Download Table]

         GEOGRAPHIC DISTRIBUTION BY STATE OF THE MORTGAGE LOANS         
------------------------------------------------------------------------
                                          AGGREGATE         PERCENTAGE  
                                          PRINCIPAL           OF THE    
                                       BALANCE OF THE       AGGREGATE   
                          NUMBER OF       MORTGAGE          PRINCIPAL   
                          MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
         STATE              LOANS       CUT-OFF DATE      MORTGAGE LOANS
------------------------------------------------------------------------
                                                                        
Arizona.................       94     $   58,268,835.81         1.82%   
California..............    3,406      2,150,351,666.69        67.18    
Colorado................       64         45,623,063.39         1.43    
Connecticut.............       69         50,868,655.00         1.59    
Delaware................        5          2,700,758.05         0.08    
District of Columbia....       13          8,264,384.84         0.26    
Florida.................      247        162,608,989.00         5.08    
Georgia.................       26         15,208,398.61         0.48    
Idaho...................        4          3,438,281.12         0.11    
Illinois................      102         60,114,669.53         1.88    
Indiana.................        5          3,647,265.58         0.11    
Kansas..................        1          1,233,940.88         0.04    
Kentucky................        2          1,110,549.99         0.03    
Maryland................       92         54,884,122.90         1.71    
Massachusetts...........      152         89,762,570.76         2.80    
Michigan................       28         16,535,919.26         0.52    
Minnesota...............       16          9,411,189.84         0.29    
Missouri................        1            997,210.30         0.03    
Montana.................        2          2,356,868.57         0.07    
Nevada..................       79         42,320,847.92         1.32    
New Hampshire...........        6          2,794,566.91         0.09    
New Jersey..............      140         86,343,500.80         2.70    
New York................      183        119,653,855.39         3.74    
North Carolina..........        9          6,660,741.65         0.21    
Ohio....................        8          4,542,080.23         0.14    
Oregon..................       25         13,631,277.15         0.43    
Pennsylvania............       17         12,801,682.44         0.40    
Rhode Island............        7          3,655,646.55         0.11    
South Carolina..........        7          4,782,931.88         0.15    
Texas...................       14          8,397,044.31         0.26    
Utah....................       11          7,586,947.94         0.24    
Virginia................       90         52,211,227.31         1.63    
Washington..............      146         95,204,171.87         2.97    
Wisconsin...............        6          3,095,432.11         0.10    
                            -----     -----------------       ------    
  Total.................    5,077     $3,201,069,294.58       100.00%   
                            -----     -----------------       ------    
                            -----     -----------------       ------    

No more than approximately 0.6% of the mortgage loans will be secured by
mortgaged properties in any one California zip code area, and no more than      
approximately 0.3% of the mortgage loans will be secured by mortgaged properties
in any single zip code area outside of California.                              

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               INTEREST RATE FLOOR OF THE MORTGAGE LOANS                
------------------------------------------------------------------------
                                          AGGREGATE         PERCENTAGE  
                                          PRINCIPAL           OF THE    
                                       BALANCES OF THE      AGGREGATE   
                          NUMBER OF       MORTGAGE          PRINCIPAL   
                          MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
INTEREST RATE FLOOR (%)     LOANS       CUT-OFF DATE      MORTGAGE LOANS
------------------------------------------------------------------------
                                                                        
1.700...................        1     $      823,494.41         0.03%   
1.750...................       16         11,515,051.16         0.36    
1.770...................        2          2,996,277.29         0.09    
1.800...................       40         27,476,484.71         0.86    
1.850...................       10          6,716,444.78         0.21    
1.870...................        3          2,935,574.67         0.09    
1.890...................        1            471,417.58         0.01    
1.900...................       51         36,917,277.82         1.15    
1.920...................        1          1,278,156.79         0.04    
1.940...................        1            823,045.07         0.03    
1.950...................       68         43,688,332.83         1.36    
1.970...................        1            933,683.95         0.03    
2.000...................      100         65,261,685.15         2.04    
2.010...................        1          1,123,016.56         0.04    
2.020...................        5          2,842,486.83         0.09    
2.040...................        1            897,686.99         0.03    
2.050...................      298        182,777,055.00         5.71    
2.070...................        7          4,972,313.59         0.16    
2.090...................        1            646,839.67         0.02    
2.100...................       29         16,421,003.88         0.51    
2.120...................       27         16,290,018.26         0.51    
2.140...................        4          2,343,175.79         0.07    
2.150...................      656        420,324,183.65        13.13    
2.165...................        1            484,088.48         0.02    
2.170...................        2          1,395,284.31         0.04    
2.171...................        1            523,821.44         0.02    
2.190...................        6          3,998,020.88         0.12    
2.200...................      186        112,717,619.23         3.52    
2.210...................        2          2,704,771.27         0.08    
2.220...................       43         27,682,262.91         0.86    
2.250...................      197        128,240,314.07         4.01    
2.260...................        2          1,564,657.53         0.05    
2.270...................       14          8,906,688.36         0.28    
2.290...................       19         12,429,792.51         0.39    
2.295...................        1            846,266.57         0.03    
2.300...................      486        304,839,561.42         9.52    
2.302...................        1            638,533.86         0.02    
2.320...................       13          8,290,747.61         0.26    
2.325...................        1          1,079,118.80         0.03    
2.340...................        7          3,661,333.68         0.11    
2.350...................      313        176,658,589.59         5.52    
2.360...................       10          7,652,288.37         0.24    
2.370...................       47         28,645,583.99         0.89    
2.388...................        1          1,119,876.18         0.03    
2.390...................       17         10,057,074.30         0.31    
2.400...................    1,125        670,637,420.14        20.95    
2.407...................        1            444,359.20         0.01    
2.410...................        1            533,803.86         0.02    
2.420...................       28         16,209,805.28         0.51    
2.430...................        1          1,500,753.89         0.05    
2.435...................        1            893,738.31         0.03    
2.440...................       14          9,275,529.47         0.29    
2.450...................       97         67,239,368.45         2.10    
2.460...................        5          4,301,855.65         0.13    

                                                                [Download Table]

         INTEREST RATE FLOOR OF THE MORTGAGE LOANS -- CONTINUED         
------------------------------------------------------------------------
                                          AGGREGATE         PERCENTAGE  
                                          PRINCIPAL           OF THE    
                                       BALANCES OF THE      AGGREGATE   
                          NUMBER OF       MORTGAGE          PRINCIPAL   
                          MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
INTEREST RATE FLOOR (%)     LOANS       CUT-OFF DATE      MORTGAGE LOANS
------------------------------------------------------------------------
                                                                        
2.470...................       58     $   35,670,082.73         1.11%   
2.475...................        1          1,483,959.80         0.05    
2.490...................       32         21,110,841.15         0.66    
2.495...................        1            623,930.61         0.02    
2.500...................       50         35,426,817.00         1.11    
2.504...................        1            419,037.84         0.01    
2.510...................        4          3,581,106.03         0.11    
2.515...................        1            473,061.88         0.01    
2.520...................        7          5,120,485.42         0.16    
2.525...................        2          1,971,331.47         0.06    
2.540...................       63         39,223,290.36         1.23    
2.550...................      113         87,270,505.32         2.73    
2.560...................       10          6,262,435.60         0.20    
2.570...................        3          1,525,248.45         0.05    
2.575...................        2          1,795,784.60         0.06    
2.580...................        4          4,248,597.00         0.13    
2.590...................        5          4,483,709.72         0.14    
2.600...................      118         62,915,338.99         1.97    
2.610...................       24         19,526,061.14         0.61    
2.620...................        5          7,410,941.27         0.23    
2.640...................      165        107,901,452.08         3.37    
2.645...................        7          6,180,313.39         0.19    
2.650...................      116         64,010,093.15         2.00    
2.660...................        1            674,826.23         0.02    
2.670...................       10          7,476,920.36         0.23    
2.680...................        7          3,820,271.57         0.12    
2.690...................        3          1,464,383.04         0.05    
2.700...................       19         12,006,489.80         0.38    
2.710...................       14          8,219,379.94         0.26    
2.720...................       15         11,065,476.57         0.35    
2.730...................        3          1,581,167.89         0.05    
2.740...................        1            499,826.20         0.02    
2.745...................        3          1,865,198.40         0.06    
2.750...................       45         29,396,226.35         0.92    
2.760...................        2          3,504,073.40         0.11    
2.770...................        1            698,434.28         0.02    
2.780...................        6          4,869,003.04         0.15    
2.790...................        5          5,416,097.63         0.17    
2.800...................       16         11,245,129.32         0.35    
2.810...................        1            520,895.16         0.02    
2.815...................        1            374,589.85         0.01    
2.820...................       15         11,203,094.30         0.35    
2.830...................        8          5,391,820.67         0.17    
2.850...................       21         13,058,143.50         0.41    
2.860...................        3          3,719,771.30         0.12    
2.870...................        4          2,191,070.93         0.07    
2.880...................        1            404,072.21         0.01    
2.890...................        5          3,220,152.92         0.10    
2.900...................       79         51,586,589.67         1.61    
2.910...................        3          2,657,104.99         0.08    
2.920...................        3          2,911,875.78         0.09    
2.930...................       18         10,173,777.91         0.32    
2.950...................        5          5,571,370.33         0.17    
                            -----     -----------------       ------    
  Total.................    5,077     $3,201,069,294.58       100.00%   
                            -----     -----------------       ------    
                            -----     -----------------       ------    

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             SCHEDULED MATURITY YEARS OF THE MORTGAGE LOANS             
------------------------------------------------------------------------
                                          AGGREGATE         PERCENTAGE  
                                          PRINCIPAL           OF THE    
                                       BALANCE OF THE       AGGREGATE   
                          NUMBER OF       MORTGAGE          PRINCIPAL   
                          MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
    YEAR OF MATURITY        LOANS       CUT-OFF DATE      MORTGAGE LOANS
------------------------------------------------------------------------
                                                                        
2034....................      133     $   66,837,331.38         2.09%   
2035....................    4,608      2,911,017,788.43        90.94    
2044....................        4          2,879,209.25         0.09    
2045....................      332        220,334,965.52         6.88    
                            -----     -----------------       ------    
  Total.................    5,077     $3,201,069,294.58       100.00%   
                            -----     -----------------       ------    
                            -----     -----------------       ------    

   The weighted average remaining term of the mortgage loans as of the Cut-Off
Date is approximately 364 months.                                               

The latest scheduled maturity of any of the mortgage loans is July 2045.

                                                                [Download Table]

           DOCUMENTATION PROGRAM TYPES OF THE MORTGAGE LOANS            
------------------------------------------------------------------------
                                          AGGREGATE         PERCENTAGE  
                                          PRINCIPAL           OF THE    
                                       BALANCE OF THE       AGGREGATE   
                          NUMBER OF       MORTGAGE          PRINCIPAL   
   LOAN DOCUMENTATION     MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
      PROGRAM TYPE          LOANS       CUT-OFF DATE      MORTGAGE LOANS
------------------------------------------------------------------------
                                                                        
Full Documentation......    1,571     $  891,404,678.72        27.85%   
Reduced Documentation...    3,506      2,309,664,615.86        72.15    
                            -----     -----------------       ------    
  Total.................    5,077     $3,201,069,294.58       100.00%   
                            -----     -----------------       ------    
                            -----     -----------------       ------    

As of the Cut-Off Date, the weighted average loan-to-value ratio of the 
mortgage loans originated under a reduced documentation program was             
approximately 67.5%.                                                            

                                                                [Download Table]

                     PURPOSE OF THE MORTGAGE LOANS                      
------------------------------------------------------------------------
                                          AGGREGATE         PERCENTAGE  
                                          PRINCIPAL           OF THE    
                                       BALANCE OF THE       AGGREGATE   
                          NUMBER OF       MORTGAGE          PRINCIPAL   
                          MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
    PURPOSE OF LOAN         LOANS       CUT-OFF DATE      MORTGAGE LOANS
------------------------------------------------------------------------
                                                                        
Purchase Loans..........    1,583     $1,006,186,185.22        31.43%   
Rate/Term Refinances....      645        415,727,726.67        12.99    
Home Improvement                                                        
 Refi's.................       65         39,398,617.99         1.23    
Cash Out Refinances.....    2,784      1,739,756,764.70        54.35    
                            -----     -----------------       ------    
  Total.................    5,077     $3,201,069,294.58       100.00%   
                            -----     -----------------       ------    
                            -----     -----------------       ------    

                                                                [Download Table]

         YEARS OF INITIAL MONTHLY PAYMENTS OF THE MORTGAGE LOANS         
-------------------------------------------------------------------------
                                           AGGREGATE         PERCENTAGE  
                                           PRINCIPAL           OF THE    
                                        BALANCE OF THE       AGGREGATE   
                           NUMBER OF       MORTGAGE          PRINCIPAL   
     YEAR OF INITIAL       MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
     MONTHLY PAYMENT         LOANS       CUT-OFF DATE      MORTGAGE LOANS
-------------------------------------------------------------------------
                                                                         
2004.....................       95     $   48,608,531.15         1.52%   
2005.....................    4,982      3,152,460,763.43        98.48    
                             -----     -----------------       ------    
  Total..................    5,077     $3,201,069,294.58       100.00%   
                             -----     -----------------       ------    
                             -----     -----------------       ------    

                                                                [Download Table]

                 OCCUPANCY STATUS OF THE MORTGAGE LOANS                  
-------------------------------------------------------------------------
                                           AGGREGATE         PERCENTAGE  
                                           PRINCIPAL           OF THE    
                                        BALANCE OF THE       AGGREGATE   
                           NUMBER OF       MORTGAGE          PRINCIPAL   
                           MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
    OCCUPANCY STATUS         LOANS       CUT-OFF DATE      MORTGAGE LOANS
-------------------------------------------------------------------------
                                                                         
Owner Occupied...........    4,751     $2,980,013,916.17        93.09%   
Owner Occupied -- 2nd                                                    
 Home....................      326        221,055,378.41         6.91    
                             -----     -----------------       ------    
  Total..................    5,077     $3,201,069,294.58       100.00%   
                             -----     -----------------       ------    
                             -----     -----------------       ------    

                                                                [Download Table]

            CREDIT SCORE DISTRIBUTION OF THE MORTGAGE LOANS             
------------------------------------------------------------------------
                                          AGGREGATE         PERCENTAGE  
                                          PRINCIPAL           OF THE    
                                       BALANCE OF THE       AGGREGATE   
                          NUMBER OF       MORTGAGE          PRINCIPAL   
                          MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
      CREDIT SCORE          LOANS       CUT-OFF DATE      MORTGAGE LOANS
------------------------------------------------------------------------
                                                                        
620 - 639...............      343     $  204,670,406.27         6.39%   
640 - 659...............      434        257,671,476.59         8.05    
660 - 679...............      605        359,485,558.88        11.23    
680 - 699...............      839        569,966,710.75        17.81    
700 - 719...............      890        573,344,283.34        17.91    
720 - 739...............      751        476,711,812.66        14.89    
740 - 759...............      520        324,251,978.76        10.13    
760 - 779...............      444        279,701,914.16         8.74    
780 - 799...............      242        148,714,774.88         4.65    
800 or greater..........        9          6,550,378.29         0.20    
                            -----     -----------------       ------    
  Total.................    5,077     $3,201,069,294.58       100.00%   
                            -----     -----------------       ------    
                            -----     -----------------       ------    

 As of the Cut-Off Date, the weighted average credit score of the mortgage
loans was approximately 707.                                                    

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                                                                [Download Table]

                     MARGINS OF THE MORTGAGE LOANS                      
------------------------------------------------------------------------
                                          AGGREGATE         PERCENTAGE  
                                          PRINCIPAL           OF THE    
                                       BALANCE OF THE       AGGREGATE   
                          NUMBER OF       MORTGAGE          PRINCIPAL   
                          MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
    GROSS MARGIN (%)        LOANS       CUT-OFF DATE      MORTGAGE LOANS
------------------------------------------------------------------------
                                                                        
1.700...................        1     $      823,494.41         0.03%   
1.750...................       16         11,515,051.16         0.36    
1.770...................        2          2,996,277.29         0.09    
1.800...................       40         27,476,484.71         0.86    
1.850...................       10          6,716,444.78         0.21    
1.870...................        3          2,935,574.67         0.09    
1.890...................        1            471,417.58         0.01    
1.900...................       51         36,917,277.82         1.15    
1.920...................        1          1,278,156.79         0.04    
1.940...................        1            823,045.07         0.03    
1.950...................       68         43,688,332.83         1.36    
1.970...................        1            933,683.95         0.03    
2.000...................      100         65,261,685.15         2.04    
2.010...................        1          1,123,016.56         0.04    
2.020...................        5          2,842,486.83         0.09    
2.040...................        1            897,686.99         0.03    
2.050...................      298        182,777,055.00         5.71    
2.070...................        7          4,972,313.59         0.16    
2.090...................        1            646,839.67         0.02    
2.100...................       29         16,421,003.88         0.51    
2.120...................       27         16,290,018.26         0.51    
2.140...................        4          2,343,175.79         0.07    
2.150...................      656        420,324,183.65        13.13    
2.165...................        1            484,088.48         0.02    
2.170...................        2          1,395,284.31         0.04    
2.171...................        1            523,821.44         0.02    
2.190...................        6          3,998,020.88         0.12    
2.200...................      186        112,717,619.23         3.52    
2.210...................        2          2,704,771.27         0.08    
2.220...................       43         27,682,262.91         0.86    
2.250...................      197        128,240,314.07         4.01    
2.260...................        2          1,564,657.53         0.05    
2.270...................       14          8,906,688.36         0.28    
2.290...................       19         12,429,792.51         0.39    
2.295...................        1            846,266.57         0.03    
2.300...................      486        304,839,561.42         9.52    
2.302...................        1            638,533.86         0.02    
2.320...................       13          8,290,747.61         0.26    
2.325...................        1          1,079,118.80         0.03    
2.340...................        7          3,661,333.68         0.11    
2.350...................      313        176,658,589.59         5.52    
2.360...................       10          7,652,288.37         0.24    
2.370...................       47         28,645,583.99         0.89    
2.388...................        1          1,119,876.18         0.03    
2.390...................       17         10,057,074.30         0.31    
2.400...................    1,125        670,661,211.96        20.95    
2.407...................        1            444,359.20         0.01    
2.410...................        1            533,803.86         0.02    
2.420...................       28         16,209,805.28         0.51    
2.430...................        1          1,500,753.89         0.05    
2.435...................        1            893,738.31         0.03    
2.440...................       14          9,275,529.47         0.29    
2.450...................       97         67,239,368.45         2.10    
2.460...................        5          4,301,855.65         0.13    
2.470...................       58         35,670,082.73         1.11    

                                                                [Download Table]

              MARGINS OF THE MORTGAGE LOANS -- (CONTINUED)              
------------------------------------------------------------------------
                                          AGGREGATE         PERCENTAGE  
                                          PRINCIPAL           OF THE    
                                       BALANCE OF THE       AGGREGATE   
                          NUMBER OF       MORTGAGE          PRINCIPAL   
                          MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
    GROSS MARGIN (%)        LOANS       CUT-OFF DATE      MORTGAGE LOANS
------------------------------------------------------------------------
                                                                        
2.475...................        1     $    1,483,959.80         0.05%   
2.490...................       32         21,110,841.15         0.66    
2.495...................        1            623,930.61         0.02    
2.500...................       48         33,687,411.11         1.05    
2.504...................        1            419,037.84         0.01    
2.510...................        4          3,581,106.03         0.11    
2.515...................        1            473,061.88         0.01    
2.520...................        7          5,120,485.42         0.16    
2.525...................        2          1,971,331.47         0.06    
2.540...................       63         39,223,290.36         1.23    
2.550...................      113         87,270,505.32         2.73    
2.560...................       10          6,262,435.60         0.20    
2.570...................        3          1,525,248.45         0.05    
2.575...................        2          1,795,784.60         0.06    
2.580...................        4          4,248,597.00         0.13    
2.590...................        5          4,483,709.72         0.14    
2.600...................      120         64,630,953.06         2.02    
2.610...................       24         19,526,061.14         0.61    
2.620...................        5          7,410,941.27         0.23    
2.640...................      165        107,901,452.08         3.37    
2.645...................        7          6,180,313.39         0.19    
2.650...................      116         64,010,093.15         2.00    
2.660...................        1            674,826.23         0.02    
2.670...................       10          7,476,920.36         0.23    
2.680...................        7          3,820,271.57         0.12    
2.690...................        3          1,464,383.04         0.05    
2.700...................       19         12,006,489.80         0.38    
2.710...................       14          8,219,379.94         0.26    
2.720...................       15         11,065,476.57         0.35    
2.730...................        3          1,581,167.89         0.05    
2.740...................        1            499,826.20         0.02    
2.745...................        3          1,865,198.40         0.06    
2.750...................       45         29,396,226.35         0.92    
2.760...................        2          3,504,073.40         0.11    
2.770...................        1            698,434.28         0.02    
2.780...................        6          4,869,003.04         0.15    
2.790...................        5          5,416,097.63         0.17    
2.800...................       16         11,245,129.32         0.35    
2.810...................        1            520,895.16         0.02    
2.815...................        1            374,589.85         0.01    
2.820...................       15         11,203,094.30         0.35    
2.830...................        8          5,391,820.67         0.17    
2.850...................       21         13,058,143.50         0.41    
2.860...................        3          3,719,771.30         0.12    
2.870...................        4          2,191,070.93         0.07    
2.880...................        1            404,072.21         0.01    
2.890...................        5          3,220,152.92         0.10    
2.900...................       79         51,586,589.67         1.61    
2.910...................        3          2,657,104.99         0.08    
2.920...................        3          2,911,875.78         0.09    
2.930...................       18         10,173,777.91         0.32    
2.950...................        5          5,571,370.33         0.17    
                            -----     -----------------       ------    
  Total.................    5,077     $3,201,069,294.58       100.00%   
                            -----     -----------------       ------    
                            -----     -----------------       ------    

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                                                                [Download Table]

       FIRST INTEREST RATE ADJUSTMENT DATE OF THE MORTGAGE LOANS        
------------------------------------------------------------------------
                                          AGGREGATE         PERCENTAGE  
                                          PRINCIPAL           OF THE    
                                       BALANCE OF THE       AGGREGATE   
                          NUMBER OF       MORTGAGE          PRINCIPAL   
                          MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
       MONTH/YEAR           LOANS       CUT-OFF DATE      MORTGAGE LOANS
------------------------------------------------------------------------
                                                                        
09/2004.................       10     $    5,208,740.63         0.16%   
10/2004.................       29         14,528,114.21         0.45    
11/2004.................       18          8,924,828.74         0.28    
12/2004.................       36         18,841,757.17         0.59    
01/2005.................       43         21,707,476.98         0.68    
02/2005.................      341        187,198,992.54         5.85    
03/2005.................      200        123,372,060.73         3.85    
04/2005.................      370        224,940,766.86         7.03    
05/2005.................     1025        632,496,427.70        19.76    
06/2005.................     1107        711,759,315.46        22.24    
07/2005.................      865        564,833,551.56        17.65    
08/2005.................    1,033        687,257,262.00        21.47    
                            -----     -----------------       ------    
  Total.................    5,077     $3,201,069,294.58       100.00%   
                            -----     -----------------       ------    
                            -----     -----------------       ------    

                                                                [Download Table]

                  ORIGINAL TERMS OF THE MORTGAGE LOANS                  
------------------------------------------------------------------------
                                          AGGREGATE         PERCENTAGE  
                                          PRINCIPAL           OF THE    
                                       BALANCE OF THE       AGGREGATE   
                          NUMBER OF       MORTGAGE          PRINCIPAL   
       LOAN TERM          MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
      (IN MONTHS)           LOANS       CUT-OFF DATE      MORTGAGE LOANS
------------------------------------------------------------------------
                                                                        
360.....................    4,741     $2,977,855,119.81        93.03%   
480.....................      336        223,214,174.77         6.97    
                            -----     -----------------       ------    
  Total.................    5,077     $3,201,069,294.58       100.00%   
                            -----     -----------------       ------    
                            -----     -----------------       ------    

                                                                [Download Table]

              INTEREST RATE CEILING OF THE MORTGAGE LOANS               
------------------------------------------------------------------------
                                          AGGREGATE         PERCENTAGE  
                                          PRINCIPAL           OF THE    
                                       BALANCE OF THE       AGGREGATE   
                          NUMBER OF       MORTGAGE          PRINCIPAL   
                          MORTGAGE     LOANS AS OF THE    BALANCE OF ALL
    CEILING RATE (%)        LOANS       CUT-OFF DATE      MORTGAGE LOANS
------------------------------------------------------------------------
                                                                        
 9.800..................        2     $    1,754,871.27         0.05%   
 9.850..................        3          1,915,635.10         0.06    
 9.900..................        2          1,137,375.66         0.04    
 9.950..................    4,258      2,584,023,308.01        80.72    
 9.985..................        1            893,738.31         0.03    
10.000..................        2          1,097,488.22         0.03    
10.020..................        3          2,795,916.64         0.09    
10.038..................        1          1,119,876.18         0.03    
10.050..................      502        334,594,299.40        10.45    
10.090..................       20         17,132,218.84         0.54    
10.100..................        1            361,170.71         0.01    
10.120..................        1            464,450.09         0.01    
10.125..................        6          6,330,194.67         0.20    
10.140..................        1          1,011,621.36         0.03    
10.150..................      103         63,447,219.77         1.98    
10.155..................        3          1,865,198.40         0.06    
10.160..................       40         34,934,980.62         1.09    
10.190..................       18         13,322,612.19         0.42    
10.195..................        9          7,650,510.57         0.24    
10.200..................       28         52,223,985.69         1.63    
10.220..................        3          2,557,468.27         0.08    
10.225..................        1            374,589.85         0.01    
10.230..................        2          2,847,016.12         0.09    
10.250..................        9          4,342,487.41         0.14    
10.260..................       10          7,497,351.38         0.23    
10.265..................        1            473,061.88         0.01    
10.270..................        1            715,052.62         0.02    
10.300..................        4          5,540,480.39         0.17    
10.330..................        4          3,424,625.04         0.11    
10.350..................        1            451,028.82         0.01    
10.360..................        1            736,108.24         0.02    
10.370..................       17         15,417,428.58         0.48    
10.400..................        1            499,484.29         0.02    
10.410..................        1          2,305,226.08         0.07    
10.450..................       11         17,540,359.59         0.55    
10.470..................        1          1,050,167.41         0.03    
10.520..................        1            698,434.28         0.02    
10.550..................        1          2,140,465.25         0.07    
10.580..................        1          1,117,434.25         0.03    
10.660..................        1          1,859,578.64         0.06    
10.950..................        1          1,404,774.49         0.04    
                            -----     -----------------       ------    
  Total.................    5,077     $3,201,069,294.58       100.00%   
                            -----     -----------------       ------    
                            -----     -----------------       ------    

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                                                                      APPENDIX C

GLOBAL CLEARANCE, SETTLEMENT AND TAX DOCUMENTATION PROCEDURES 

   Except in certain limited circumstances, the Book-Entry Certificates, which
are referred to as the global securities, will be available only in book-entry  
form. Investors in the global securities may hold interests in these global     
securities through any of DTC, Euroclear or Clearstream. Initial settlement and 
all secondary trades will settle in same-day funds.                             

Secondary market trading between investors holding interests in global  
securities through Euroclear and Clearstream will be conducted in accordance    
with their normal rules and operating procedures and in accordance with         
conventional eurobond practice. Secondary market trading between investors      
holding interests in global securities through DTC will be conducted according  
to the rules and procedures applicable to U.S. corporate debt obligations.      

    Secondary cross-market trading between investors holding interests in global
securities through Euroclear or Clearstream and investors holding interests in  
global securities through DTC participants will be effected on a                
delivery-against-payment basis through the respective depositories of Euroclear 
and Clearstream, in such capacity, and other DTC participants.                  

Although DTC, Euroclear and Clearstream are expected to follow the      
procedures described below in order to facilitate transfers of interests in the 
global securities among participants of DTC, Euroclear and Clearstream, they are
under no obligation to perform or continue to perform those procedures, and     
those procedures may be discontinued at any time. None of Washington Mutual     
Mortgage Securities Corp., Washington Mutual Bank, the Trust or the trustee will
have any responsibility for the performance by DTC, Euroclear and Clearstream or
their respective participants or indirect participants of their respective      
obligations under the rules and procedures governing their obligations.         

 Non-U.S. holders of global securities will be subject to U.S. withholding
taxes unless those holders meet certain requirements and deliver appropriate    
U.S. tax documents to the securities clearing organizations or their            
participants.                                                                   

INITIAL SETTLEMENT                                                              

The global securities will be registered in the name of Cede & Co. as   
nominee of DTC. Investors' interests in the global securities will be           
represented through financial institutions acting on their behalf as direct and 
indirect participants in DTC. Clearstream and Euroclear will hold positions on  
behalf of their participants through their respective depositories, which in    
turn will hold such positions in accounts as DTC participants.                  

Investors electing to hold interests in global securities through DTC   
participants, rather than through Clearstream or Euroclear accounts, will be    
subject to the settlement practices applicable to similar issues of pass-through
certificates. Investors' securities custody accounts will be credited with their
holdings against payment in same-day funds on the settlement date.              

Investors electing to hold interests in global securities through       
Clearstream or Euroclear accounts will follow the settlement procedures         
applicable to conventional eurobonds, except that there will be no temporary    
global security and no 'lock-up' or restricted period. Interests in global      
securities will be credited to the securities custody accounts on the settlement
date against payment in same-day funds.                                         

SECONDARY MARKET TRADING                                                        

Since the purchaser determines the place of delivery, it is important to
establish at the time of the trade where both the purchaser's and seller's      
accounts are located to ensure that settlement can be made on the desired value 
date.                                                                           

Transfers between DTC Participants. Secondary market trading between DTC
participants will be settled using the DTC procedures applicable to similar     
issues of pass-through certificates in same-day funds.                          

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Transfers between Clearstream and/or Euroclear Participants. Secondary  
market trading between Clearstream participants or Euroclear participants and/or
investors holding interests in global securities through them will be settled   
using the procedures applicable to conventional eurobonds in same-day funds.    

 Transfers between DTC seller and Clearstream or Euroclear purchaser. When
interests in global securities are to be transferred on behalf of a seller from 
the account of a DTC participant to the account of a Clearstream participant or 
a Euroclear participant for a purchaser, the purchaser will send instructions to
Clearstream or Euroclear through a Clearstream participant or Euroclear         
participant at least one business day prior to settlement. Clearstream or the   
Euroclear operator will instruct its respective depository to receive an        
interest in the global securities against payment. Payment will include interest
accrued on the global securities from and including the last distribution date  
to but excluding the settlement date. Payment will then be made by the          
respective depository to the DTC participant's account against delivery of an   
interest in the global securities. After this settlement has been completed, the
interest will be credited to the respective clearing system, and by the clearing
system, in accordance with its usual procedures, to the Clearstream             
participant's or Euroclear participant's account. The credit of this interest   
will appear on the next business day and the cash debit will be back-valued to, 
and the interest on the global securities will accrue from, the value date,     
which would be the preceding day when settlement occurred in New York. If       
settlement is not completed through DTC on the intended value date, i.e., the   
trade fails, the Clearstream or Euroclear cash debit will be valued instead as  
of the actual settlement date.                                                  

Clearstream participants and Euroclear participants will need to make   
available to the respective clearing system the funds necessary to process      
same-day funds settlement. The most direct means of doing so is to pre-position 
funds for settlement from cash on hand, in which case the Clearstream           
participants or Euroclear participants will take on credit exposure to          
Clearstream or the Euroclear operator until interests in the global securities  
are credited to their accounts one day later.                                   

  As an alternative, if Clearstream or the Euroclear operator has extended a
line of credit to them, Clearstream participants or Euroclear participants can  
elect not to pre-position funds and allow that credit line to be drawn upon.    
Under this procedure, Clearstream participants or Euroclear participants        
receiving interests in global securities for purchasers would incur overdraft   
charges for one day, to the extent they cleared the overdraft when interests in 
the global securities were credited to their accounts. However, interest on the 
global securities would accrue from the value date. Therefore, the investment   
income on the interest in the global securities earned during that one-day      
period would tend to offset the amount of these overdraft charges, although this
result will depend on each Clearstream participant's or Euroclear participant's 
particular cost of funds.                                                       

 Since the settlement through DTC will take place during New York business
hours, DTC participants are subject to DTC procedures for transferring interests
in global securities to the respective depository of Clearstream or Euroclear   
for the benefit of Clearstream participants or Euroclear participants. The sale 
proceeds will be available to the DTC seller on the settlement date. Thus, to   
the seller settling the sale through a DTC participant, a cross-market          
transaction will settle no differently than a sale to a purchaser settling      
through a DTC participant.                                                      

 Finally, intra-day traders that use Clearstream participants or Euroclear
participants to purchase interests in global securities from DTC participants or
sellers settling through them for delivery to Clearstream participants or       
Euroclear participants should note that these trades will automatically fail on 
the sale side unless affirmative action is taken. At least three techniques     
should be available to eliminate this potential condition:                      

      borrowing interests in global securities through Clearstream
  or Euroclear for one day, until the purchase side of the
     intra-day trade is reflected in the relevant Clearstream or
      Euroclear accounts, in accordance with the clearing system's
customary procedures;                                 

borrowing interests in global securities in the United
      States from a DTC participant no later than one day prior to
settlement, which would give sufficient time for such 
  interests to be reflected in the relevant Clearstream or
    Euroclear accounts in order to settle the sale side of the
trade; or                                             

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      staggering the value dates for the buy and sell sides of the
    trade so that the value date for the purchase from the DTC
     participant is at least one day prior to the value date for
the sale to the Clearstream participant or Euroclear  
participant.                                          

   Transfers between Clearstream or Euroclear seller and DTC purchaser. Due to
time zone differences in their favor, Clearstream participants and Euroclear    
participants may employ their customary procedures for transactions in which    
interests in global securities are to be transferred by the respective clearing 
system, through the respective depository, to a DTC participant. The seller will
send instructions to Clearstream or the Euroclear operator through a Clearstream
participant or Euroclear participant at least one business day prior to         
settlement. Clearstream or Euroclear will instruct its respective depository, to
credit an interest in the global securities to the DTC participant's account    
against payment. Payment will include interest accrued on the global securities 
from and including the last distribution date to but excluding the settlement   
date. The payment will then be reflected in the account of the Clearstream      
participant or Euroclear participant the following business day, and receipt of 
the cash proceeds in the Clearstream participant's or Euroclear participant's   
account would be back-valued to the value date, which would be the preceding    
day, when settlement occurred through DTC in New York. If settlement is not     
completed on the intended value date, i.e., the trade fails, receipt of the cash
proceeds in the Clearstream participant's or Euroclear participant's account    
would instead be valued as of the actual settlement date.                       

CERTAIN U.S. FEDERAL INCOME TAX DOCUMENTATION REQUIREMENTS                      

 A beneficial owner who is an individual or corporation holding the global
security on its own behalf or holding securities through Clearstream or         
Euroclear, or through DTC if the holder has an address outside the U.S., will be
subject to the 30% U.S. withholding tax that typically applies to payments of   
interest, including original issue discount, on registered debt issued by U.S.  
persons, unless:                                                                

    each clearing system, bank or other institution that holds
      customers' securities in the ordinary course of its trade or
business in the chain of intermediaries between the   
    beneficial owner or a foreign corporation or foreign trust
    and the U.S. entity required to withhold tax complies with
applicable certification requirements; and            

  the beneficial owner takes one of the following steps to
obtain an exemption or reduced tax rate:              

           Exemption for Non-U.S. Persons -- Form W-8BEN. Beneficial
        holders of global securities that are Non-U.S. persons
              (which would not include entities treated as partnerships or
      grantor trusts for U.S. federal income tax purposes)
    generally can obtain a complete exemption from the
    withholding tax by filing a signed Form W-8BEN, or
              Certificate of Foreign Status of Beneficial Owner for United
          States Tax Withholding. If the information shown on Form
           W-8BEN changes, a new Form W-8BEN must be filed within 30
days of the change.                           

           Exemption for Non-U.S. persons with effectively connected
       income -- Form W-8ECI. A Non-U.S. person, including a
            non-U.S. corporation or bank with a U.S. branch, for which
       the interest income is effectively connected with its
          conduct of a trade or business in the United States, can
             obtain an exemption from the withholding tax by filing Form
      W-8ECI, or Certificate of Foreign Person's Claim for
            Exemption from Withholding on Income Effectively Connected
       with the Conduct of a Trade or Business in the United
States.                                       

            Exemption or reduced rate for Non-U.S. persons resident in
            treaty countries -- Form W-8BEN. Non-U.S. persons residing
           in a country that has a tax treaty with the United States
           can obtain an exemption or reduced tax rate, depending on
             the treaty terms, by filing Form W-8BEN. Form W-8BEN may be
filed by Bond Holders or their agent.         

          Exemption for U.S. Persons -- Form W-9. U.S. persons can
         obtain a complete exemption from the withholding tax by
  filing Form W-9, or Payer's Request for Taxpayer
Identification Number and Certification.      

    U.S. Federal Income Tax Reporting Procedure. The holder of a global security
or, in the case of a Form W-8BEN or Form W-8ECI filer, his agent, files by      
submitting the appropriate form to the person                                   

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through whom it holds the security -- the clearing agency, in the case of       
persons holding directly on the books of the clearing agency. Form W-8BEN and   
Form W-8ECI generally are effective until the third succeeding calendar year    
from the date the form is signed. However, the W-8BEN with a taxpayer           
identification number will remain effective until a change in circumstances     
makes any information on the form incorrect, provided that the withholding agent
reports at least annually to the beneficial owner on Form 1042-S. The term 'U.S.
person' means:                                                                  

a citizen or resident of the United States;           

 a corporation, partnership or other entity treated as a
corporation or a partnership for United States federal
    income tax purposes, organized in or under the laws of the
United States or any state thereof, including for this
    purpose the District of Columbia, unless, in the case of a
     partnership, future Treasury regulations provide otherwise;

an estate that is subject to U.S. federal income tax  
regardless of the source of its income; or            

a trust if a court within the United States is able to
   exercise primary supervision of the administration of the
trust and one or more United States persons have the  
      authority to control all substantial decisions of the trust.

  Certain trusts not described in the final bullet of the preceding sentence
that were in existence on August 20, 1996 and elect to be treated as a United   
States Person will also be a U.S. person. The term 'Non-U.S. person' means any  
person who is not a U.S. person. This summary does not deal with all aspects of 
U.S. federal income tax withholding that may be relevant to foreign holders of  
the global securities. Investors are advised to consult their own tax advisors  
for specific tax advice concerning their holding and disposing of the global    
securities.                                                                     

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                                                                      SCHEDULE 1

YIELD MAINTENANCE NOTIONAL BALANCES AND STRIKE RATES

                                                        [Enlarge/Download Table]

                                                           YIELD MAINTENANCE                 
                    DISTRIBUTION DATE                     NOTIONAL BALANCE($)  STRIKE RATE(%)
                    -----------------                     -------------------  --------------
                                                                                             
October 2005.............................................    2,747,197,885        9.10998    
November 2005............................................    2,683,936,816        8.79999    
December 2005............................................    2,622,036,500        9.10999    
January 2006.............................................    2,561,463,538        8.79999    
February 2006............................................    2,502,189,134        8.79999    
March 2006...............................................    2,444,135,583        9.79642    
April 2006...............................................    2,387,292,220        8.79999    
May 2006.................................................    2,331,604,189        9.10999    
June 2006................................................    2,276,912,696        8.79999    
July 2006................................................    2,223,177,556        9.11000    
August 2006..............................................    2,170,431,295        8.80000    
September 2006...........................................    2,118,623,065        8.80000    
October 2006.............................................    2,067,940,928        9.11000    
November 2006............................................    2,018,357,462        8.80000    
December 2006............................................    1,969,848,988        9.11000    
January 2007.............................................    1,922,388,923        8.80000    
February 2007............................................    1,875,954,390        8.80000    
March 2007...............................................    1,830,483,071        9.79643    
April 2007...............................................    1,785,966,698        8.80001    
May 2007.................................................    1,742,361,365        9.11001    
June 2007................................................    1,699,539,362        8.80001    
July 2007................................................    1,657,468,605        9.11001    
August 2007..............................................    1,616,175,625        8.80001    
September 2007...........................................    1,575,619,731        8.80001    
October 2007.............................................    1,535,952,845        9.11002    
November 2007............................................    1,497,153,154        8.80002    
December 2007............................................    1,459,201,855        9.11002    
January 2008.............................................    1,422,077,801        8.80002    
February 2008............................................    1,385,762,829        8.80002    
March 2008...............................................    1,350,206,971        9.44140    
April 2008...............................................    1,315,403,832        8.80002    
May 2008.................................................    1,281,318,281        9.11003    
June 2008................................................    1,247,847,617        8.80003    
July 2008................................................    1,218,045,019        9.11003    
August 2008..............................................    1,188,829,206        8.80003    
September 2008...........................................    1,160,169,937        8.80003    
October 2008.............................................    1,135,175,749        9.11003    
November 2008............................................    1,110,733,011        8.80003    
December 2008............................................    1,086,829,692        9.11004    
January 2009.............................................    1,063,452,232        8.80004    
February 2009............................................    1,040,589,006        8.80004    
March 2009...............................................    1,018,207,710        9.79647    
April 2009...............................................      996,304,366        8.80004    
May 2009.................................................      974,856,310        9.11005    
June 2009................................................      953,796,938        8.80005    
July 2009................................................      933,109,770        9.11005    
August 2009..............................................      912,809,053        8.80005    
September 2009...........................................      892,873,785        8.80005    
October 2009.............................................      873,381,161        9.11005    
November 2009............................................      854,318,004        8.80005    
December 2009............................................      835,675,924        9.11006    

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                                                        [Enlarge/Download Table]

                                                           YIELD MAINTENANCE                 
                    DISTRIBUTION DATE                     NOTIONAL BALANCE($)  STRIKE RATE(%)
                    -----------------                     -------------------  --------------
                                                                                             
January 2010.............................................      817,439,917        8.80006    
February 2010............................................      799,601,438        8.80006    
March 2010...............................................      782,062,962        9.79650    
April 2010...............................................      764,845,121        8.80007    
May 2010.................................................      747,882,999        9.11008    
June 2010................................................      730,908,981        8.80009    
July 2010................................................      713,879,371        9.11010    
August 2010..............................................      696,890,920        8.80010    
September 2010...........................................      679,883,533        8.80010    
October 2010.............................................      663,286,794        9.11011    
November 2010............................................      647,090,853        8.80010    
December 2010............................................      631,286,097        9.11011    
January 2011.............................................      615,863,143        8.80010    
February 2011............................................      600,812,830        8.80010    
March 2011...............................................      586,126,219        9.79654    
April 2011...............................................      571,794,582        8.80010    
May 2011.................................................      557,809,399        9.11011    
June 2011................................................      544,162,356        8.80010    
July 2011................................................      530,845,336        9.11011    
August 2011..............................................      517,850,416        8.80010    
September 2011...........................................      505,169,863        8.80010    
October 2011.............................................      492,796,128        9.11011    
November 2011............................................      480,721,844        8.80010    
December 2011............................................      468,939,817        9.11011    
January 2012.............................................      457,443,027        8.80010    
February 2012............................................      446,224,623        8.80010    
March 2012...............................................      435,277,916        9.44149    
April 2012...............................................      424,596,377        8.80010    
May 2012.................................................      414,173,633        9.11011    
June 2012................................................      404,003,464        8.80010    
July 2012................................................      394,079,799        9.11011    
August 2012..............................................      384,396,712        8.80010    
September 2012...........................................      374,948,417        8.80010    
October 2012.............................................      365,729,270        9.11011    
November 2012............................................      356,733,757        8.80010    
December 2012............................................      347,956,502        9.11011    
January 2013.............................................      339,392,252        8.80010    
February 2013............................................      331,035,883        8.80010    
March 2013...............................................      322,882,392        9.79654    
April 2013...............................................      314,926,898        8.80010    
May 2013.................................................      307,164,634        9.11011    
June 2013................................................      299,590,948        8.80011    
July 2013................................................      292,201,301        9.11011    
August 2013..............................................      284,991,260        8.80011    
September 2013...........................................      277,956,500        8.80011    
October 2013.............................................      271,092,799        9.11011    
November 2013............................................      264,396,037        8.80011    
December 2013............................................      257,862,190        9.11011    
January 2014.............................................      251,487,334        8.80011    
February 2014............................................      245,267,636        8.80011    
March 2014 and thereafter................................                0        0.00000    

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INDEX OF TERMS

Below is a list of selected significant terms used in this prospectus   
supplement and the pages on which their definitions can be found.               

                                                                [Download Table]

                                        PAGE
                                        ----
                                            
Adjusted Cap Rate.....................  S-43
Adjusted Weighted Average Pass-Through      
  Rate................................  S-44
Available Distribution Amount.........  S-53
Cap Counterparty......................  S-45
Carryover Shortfall Amount............  S-45
Cede..................................  S-36
Certificate Principal Balance.........  S-36
Class Principal Balance...............  S-36
Class X Notional Amount...............  S-44
Clean-Up Call Option Date.............   S-5
Clearstream...........................  S-37
Closing Date..........................  S-29
CPR...................................  S-59
Credit Support Depletion Date.........  S-42
Curtailments..........................  S-48
Cut-Off Date..........................  S-29
Distribution Date.....................  S-41
DTC...................................  S-36
Due Date..............................  S-30
Euroclear.............................  S-37
Euroclear Clearance System............  S-38
Euroclear Operator....................  S-38
Index.................................  S-32
Liquidated Mortgage Loan..............  S-48
Liquidation Principal.................  S-48
Margin................................  S-30
Minimum Monthly Payment...............  S-30
Modeling Assumptions..................  S-60
Net Negative Amortization.............  S-43
One-Year MTA..........................  S-32
Pass-Through Rate.....................  S-44
Payment Cap...........................  S-31
Payoffs...............................  S-48
Prepayment Period.....................  S-48
Principal Payment Amount..............  S-48
Principal Prepayment Amount...........  S-48
Rate Ceiling..........................  S-30
Relief Act............................  S-25
Senior Percentage.....................  S-49
Senior Prepayment Percentage..........  S-50
Senior Principal Distribution               
  Amount..............................  S-49
Stated Principal Balance..............  S-49
Subordinate Percentage................  S-49
Subordinate Prepayment Percentage.....  S-50
Subordinate Principal Distribution          
  Amount..............................  S-50
Subordinate Principal Prepayment            
  Distribution Amount.................  S-50
Subordination Level...................  S-42
Subsequent Recoveries.................  S-48
Trust.................................  S-29
Weighted Average Pass-Through Rate....  S-44
Yield Maintenance Agreement...........  S-45
Yield Maintenance Notional Balance....  S-45

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PROSPECTUS                                                                      

WASHINGTON MUTUAL MORTGAGE
SECURITIES CORP.
DEPOSITOR AND MASTER SERVICER 

MORTGAGE PASS-THROUGH CERTIFICATES

CONSIDER CAREFULLY THE RISK FACTORS BEGINNING ON PAGE 5 IN THIS PROSPECTUS. 

A certificate will represent an interest only in the trust created for that 
series of certificates. A certificate will not represent an interest in or  
an obligation of Washington Mutual Mortgage Securities Corp., Washington    
Mutual, Inc. or any of their affiliates.                                    

This prospectus may be used to offer and sell a series of certificates only 
if accompanied by the prospectus supplement for that series.                

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. MAY PERIODICALLY ISSUE          
CERTIFICATES REPRESENTING INTERESTS IN A TRUST THAT CONSISTS PRIMARILY OF   
 MORTGAGE LOANS. THE CERTIFICATES WILL BE ISSUED IN SERIES, AND EACH SERIES OF
CERTIFICATES WILL REPRESENT INTERESTS IN A DIFFERENT TRUST ESTABLISHED BY   
WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.                                 

EACH TRUST WILL CONSIST OF:                                                 

a pool of mortgage loans secured by residential properties, which may   
include cooperative apartments, described in detail in the accompanying 
prospectus supplement;                                                  

related property and interests; and                                     

other property as described in the accompanying prospectus supplement.  

THE CERTIFICATES IN A SERIES:                                               

   will represent interest in a trust and will be paid only from the assets of
that trust; and                                                         

    may be divided into multiple classes of certificates, and, if so, each class
may:                                                                    

receive a different fixed or variable rate of interest;             

be subordinated to other classes of certificates in that series;    

represent interests in only certain of the assets of the trust;     

receive principal at different times; and                           

have different forms of credit enhancement.                         

The certificates may be offered to the public through different methods as      
described in 'Methods of Distribution' in this prospectus. WaMu Capital Corp. or
another affiliate of Washington Mutual Mortgage Securities Corp. may act as     
agent or underwriter in connection with the sale of the certificates.           

NEITHER THE SEC NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED 
OF THESE CERTIFICATES OR DETERMINED THAT THIS PROSPECTUS IS ACCURATE OR         
COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.             

August 23, 2005 

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IMPORTANT NOTICE ABOUT INFORMATION PRESENTED IN THIS
PROSPECTUS AND THE ACCOMPANYING PROSPECTUS SUPPLEMENT 

We provide information to you about the certificates in two separate    
documents that progressively provide more detail: (a) this prospectus, which    
provides general information, some of which may not apply to your series of     
certificates and (b) the accompanying prospectus supplement, which describes the
specific terms of your series of certificates.                                  

IF THE TERMS OF A PARTICULAR SERIES OF CERTIFICATES VARY BETWEEN THIS   
PROSPECTUS AND THE ACCOMPANYING PROSPECTUS SUPPLEMENT, YOU SHOULD RELY ON THE   
INFORMATION IN THE PROSPECTUS SUPPLEMENT.                                       

   You should rely only on the information provided in this prospectus and the
accompanying prospectus supplement, including the information incorporated by   
reference. We have not authorized anyone to provide you with different          
information. We are not offering the certificates in any state where the offer  
is not permitted. We do not claim the accuracy of the information in this       
prospectus or the accompanying prospectus supplement as of any date other than  
the dates stated on their respective covers.                                    

We include cross-references in this prospectus and the accompanying     
prospectus supplement to captions in these materials where you can find further 
related discussions. The following Table of Contents and the Table of Contents  
included in the accompanying prospectus supplement provide the pages on which   
these captions are located.                                                     

You can find a listing of the pages where capitalized terms used in this
prospectus are defined under the caption 'Index of Terms' beginning on page 88. 

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TABLE OF CONTENTS 

                                                                [Download Table]

                                         PAGE
                                         ----
                                             
RISK FACTORS...........................    5 
THE MORTGAGE POOLS.....................    8 
    General............................    8 
    Conversion of Mortgage Loans.......   12 
USE OF PROCEEDS........................   12 
YIELD CONSIDERATIONS...................   13 
    General............................   13 
    Effective Interest Rate............   13 
MATURITY, AVERAGE LIFE AND PREPAYMENT        
  ASSUMPTIONS..........................   15 
    Redemption of Certificates or            
      Underlying Mortgage Loans........   16 
THE COMPANY............................   16 
    Mortgage Purchase Program..........   16 
    Loan Standards.....................   17 
    Credit, Appraisal and Underwriting       
      Standards........................   17 
    Seller Warranties and                    
      Indemnification of the Company...   18 
    Relationships with Affiliates......   19 
DESCRIPTION OF CERTIFICATES............   19 
    General............................   19 
    Assignment of Mortgage Loans.......   20 
    Substitution of Mortgage Loans.....   22 
    Representations and Warranties.....   22 
    Servicing..........................   23 
    Retained Yield.....................   24 
    Payments on Mortgage Loans;              
      Custodial Accounts for P&I,            
      Investment Account, Certificate        
      Account and Reserve Account......   25 
    Pre-Funding Account................   29 
    Distributions on Certificates......   29 
    Reports to Certificateholders......   31 
    Advances...........................   32 
    Collection and Other Servicing           
      Procedures.......................   33 
    Servicing Compensation and Payment       
      of Expenses......................   34 
    Evidence as to Compliance..........   36 
    Certain Matters Regarding the            
      Master Servicer, the Servicer,         
      the Certificate Administrator and      
      the Company......................   36 
    Events of Default..................   37 
    Rights Upon Event of Default.......   38 
    Amendment..........................   38 
    List of Certificateholders.........   39 
    Termination........................   39 
    Redemption Agreement...............   40 
    Put Option.........................   40 
    The Trustee........................   40 
PRIMARY INSURANCE, FHA MORTGAGE              
  INSURANCE, VA MORTGAGE GUARANTY,           
  HAZARD INSURANCE; CLAIMS                   
  THEREUNDER...........................   41 
    Primary Insurance..................   41 
    FHA Mortgage Insurance.............   42 
    VA Mortgage Guaranty...............   43 
    Hazard Insurance...................   43 
DESCRIPTION OF CREDIT ENHANCEMENTS.....   45 
    Mortgage Pool Insurance............   46 
    Subordination......................   47 
    The Fraud Bond.....................   48 
    The Bankruptcy Bond................   49 
    Special Hazard Insurance...........   49 
    Letter of Credit...................   50 
    Reserve Fund.......................   50 
    Certificate Insurance Policies.....   51 
    Maintenance of Credit Enhancements;      
      Claims Thereunder and Other            
      Realization Upon Defaulted             
      Mortgage Loans...................   51 
CERTAIN LEGAL ASPECTS OF THE MORTGAGE        
  LOANS................................   54 
    Cooperative Loans..................   54 
    Tax Aspects of Cooperative               
      Ownership........................   55 
    Foreclosure........................   55 
    Foreclosure on Shares of                 
      Cooperatives.....................   56 
    Rights of Redemption...............   58 
    Anti-Deficiency Legislation and          
      Other Limitations on Lenders.....   58 
    Enforceability of Certain                
      Provisions.......................   59 
    Applicability of Usury Laws........   60 
    Alternative Mortgage Instruments...   60 
    Environmental Risks................   61 
ERISA CONSIDERATIONS...................   62 
    Plan Asset Regulation..............   62 
    Underwriter's Exemption and WCC          
      Exemption........................   63 
    Other Exemptions...................   65 
    Insurance Company General                
      Accounts.........................   66 
    Representations from Investing           
      Plans............................   66 
    Tax-Exempt Plan Investors..........   66 
    Consultation with Counsel..........   67 
CERTAIN FEDERAL INCOME TAX                   
  CONSEQUENCES.........................   68 
    Classification of REMICs...........   68 
    Characterization of Investments in       
      REMIC Certificates...............   68 
    Taxation of Owners of REMIC Regular      
      Certificates.....................   69 

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                                                                [Download Table]

                                         PAGE
                                         ----
                                             
        Original Issue Discount........   69 
        Market Discount and Premium....   73 
        Realized Losses................   74 
        Callable Class Certificates....   75 
    Taxation of Owners of REMIC              
      Residual Certificates............   76 
        General........................   76 
        Taxable Income or Net Loss of        
          the REMIC....................   77 
        Basis Rules and                      
          Distributions................   77 
        Excess Inclusions..............   78 
        Noneconomic REMIC Residual           
          Certificates.................   79 
        Tax-Exempt Investors...........   80 
        Real Estate Investment               
          Trusts.......................   80 
        Mark-to-Market Rules...........   80 
    Sales of REMIC Certificates........   80 
    Pass-Through of Servicing Fees.....   82 
    Prohibited Transactions and Other        
      Possible REMIC Taxes.............   82 
    Termination of a REMIC.............   82 
    Reporting and Other Administrative       
      Matters of REMICs................   82 
    Backup Withholding with Respect to       
      REMIC Certificates...............   83 
    Foreign Investors in REMIC               
      Certificates.....................   83 
        REMIC Regular Certificates.....   83 
        REMIC Residual Certificates....   84 
    New Withholding Regulations........   85 
    Tax Return Disclosure and Investor       
      List Requirements................   85 
    State and Local Taxation...........   85 
    Call Right.........................   85 
METHODS OF DISTRIBUTION................   85 
TRANSFERABILITY OF CERTIFICATES........   86 
LEGAL MATTERS..........................   86 
FINANCIAL INFORMATION..................   86 
INCORPORATION OF DOCUMENTS BY                
  REFERENCE............................   87 
ADDITIONAL INFORMATION.................   87 
INDEX OF TERMS.........................   88 

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RISK FACTORS

YOU SHOULD CONSIDER THE FOLLOWING RISK FACTORS (IN ADDITION TO THE RISK 
FACTORS IN THE PROSPECTUS SUPPLEMENT) IN DECIDING WHETHER TO PURCHASE ANY OF THE
CERTIFICATES.                                                                   

                                                        [Enlarge/Download Table]
                                                                                                              
LACK OF SECONDARY MARKETS MAY LIMIT               A secondary market for the certificates of any series may   
YOUR ABILITY TO RESELL YOUR CERTIFICATES          not develop. If a secondary market does develop, it might   
                                                  not continue or it might not be sufficiently liquid to allow
                                                  you to resell any of your certificates. An underwriter may  
                                                  decide to establish a secondary market for a particular     
                                                  series of certificates. If so, the prospectus supplement for
                                                  that series of certificates will indicate this intention.   
                                                  However, no underwriter will be obligated to do so. The     
                                                  certificates will not be listed on any securities exchange. 

THERE IS NO SOURCE OF PAYMENTS FOR YOUR           When you buy a certificate, you will not own an interest in 
CERTIFICATES OTHER THAN PAYMENTS ON THE MORTGAGE  Washington Mutual Mortgage Securities Corp., Washington     
LOANS IN THE TRUST                                Mutual, Inc. or any of their affiliates. You will own an    
                                                  interest in the Trust established for that series of        
                                                  certificates. Your payments come only from assets in the    
                                                  Trust. Therefore, the mortgagors' payments on the mortgage  
                                                  loans included in the Trust (and any credit enhancements)   
                                                  will be the sole source of payments to you. If those amounts
                                                  are insufficient to make required payments of interest or   
                                                  principal to you, there is no other source of payments.     

                                                  Moreover, no governmental agency either guarantees or       
                                                  insures payments on the Certificates or any of the mortgage 
                                                  loans.                                                      

                                                  Washington Mutual Mortgage Securities Corp. and/or the      
                                                  Servicers will have limited obligations. These will usually 
                                                  include:                                                    

                                                     the obligation under certain circumstances to repurchase 
                                                     the mortgage loans if there has been a breach of         
                                                     representations and warranties;                          

                                                     advancing payments on the mortgage loans when the        
                                                     mortgagor is delinquent if the applicable Master Servicer
                                                     believes the advance is recoverable; and                 

                                                     various servicing and/or administrative obligations made 
                                                     in the Pooling Agreement and/or servicing contracts.     

YOU BEAR THE RISK OF CERTAIN MORTGAGOR DEFAULTS;  Because your certificates represent an interest in the      
CERTAIN OF THE MORTGAGE LOANS MAY BE ESPECIALLY   mortgage loans, your investment may be affected by a decline
PRONE TO DEFAULTS                                 in real estate values and changes in individual mortgagor's 
                                                  financial conditions. Investors should be aware that value  
                                                  of the mortgaged properties may decline. If the outstanding 
                                                  balance of a mortgage loan and any secondary financing on   
                                                  the underlying property is greater than the value of the    
                                                  property, there is an increased risk of delinquency,        
                                                  foreclosure and losses. If the residential real estate      
                                                  market experiences an overall decline in property values,   
                                                  the rates of delinquencies, foreclosures and losses could be
                                                  higher than those now generally experienced in the mortgage 
                                                  lending industry. To the extent your certificates are not   
                                                  covered by credit enhancements, you will bear all of the    
                                                  risks resulting from defaults by                            

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                                               mortgagors. In addition, certain types of mortgage  
                                               loans which have higher than average rates of       
                                               default may be included in the Trust that issues    
                                               your certificate. The following types of loans may  
                                               be included:                                        

                                                  mortgage loans that are subject to 'negative     
                                                  amortization'. The principal balances of such    
                                                  loans may be increased to amounts greater than   
                                                  the value of the underlying property. This       
                                                  increases the likelihood of default;             

                                                  mortgage loans that do not fully amortize over   
                                                  their terms to maturity which are sometimes      
                                                  referred to as balloon loans. Such loans require 
                                                  a large payment at their stated maturity. These  
                                                  loans involve a greater degree of risk because   
                                                  the ability of a mortgagor to make this final    
                                                  payment typically depends on the ability to      
                                                  refinance the loan or sell the related mortgaged 
                                                  property;                                        

                                                  mortgage loans that provide for escalating or    
                                                  variable payments by the mortgagor. The mortgagor
                                                  may have qualified for such loans based on an    
                                                  income level sufficient to make the initial      
                                                  payments only. As the payments increase, the     
                                                  likelihood of default will increase; and         

                                                  mortgage loans that are concentrated in certain  
                                                  regions, states or zip code areas of the United  
                                                  States. Such geographic units may experience     
                                                  weak economic conditions and housing markets.    
                                                  This may cause higher rates of loss and          
                                                  delinquency.                                     

                                               See 'Description of the Mortgage Pools' in the      
                                               prospectus supplement to see if any of these or     
                                               other types of special risk loans are present in    
                                               the mortgage pool applicable to your certificates.  

CREDIT ENHANCEMENTS MAY BE LIMITED OR REDUCED  The prospectus supplement related to your           
AND THIS MAY CAUSE YOUR CERTIFICATES TO BEAR   certificates may specify that credit enhancements   
MORE RISK OF MORTGAGOR DEFAULTS                will provide some protection to cover certain       
                                               losses on the underlying mortgage loans. The forms  
                                               of credit enhancement include (but are not limited  
                                               to) the following: subordination of one or more     
                                               classes of certificates to other classes of         
                                               certificates in the same series; an insurance       
                                               policy on a particular class of certificates; a     
                                               letter of credit; a mortgage pool insurance policy; 
                                               a special hazard insurance policy; a fraud bond; a  
                                               bankruptcy bond; a reserve fund; or any combination 
                                               thereof. See 'Description of the Credit             
                                               Enhancements' herein. See also 'Credit              
                                               Enhancements' in the prospectus supplement in order 
                                               to see what forms of credit enhancements apply to   
                                               your certificates.                                  

                                               Regardless of the form of credit enhancement, an    
                                               investor should be aware that:                      

                                                  The amount of coverage is usually limited;       

                                                  The amount of coverage will usually be reduced   
                                                  over time according to a schedule or formula;    

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                                                     The particular form of credit enhancements may     
                                                     provide coverage only to certain types of losses on
                                                     the mortgage loans, and not to other types of      
                                                     losses;                                            

                                                     The particular form of credit enhancements may     
                                                     provide coverage only to certain certificates and  
                                                     not other certificates of the same series; and     

                                                     If the applicable rating agencies believe that     
                                                     the rating on the certificates will not be         
                                                     adversely affected, certain types of credit        
                                                     enhancements may be reduced or terminated.         

IF THE RATE OF PREPAYMENTS ON THE MORTGAGE LOANS  The yield to maturity of your certificates will       
IS DIFFERENT THAN EXPECTED, YOUR YIELD MAY BE     depend primarily on the price you paid for your       
CONSIDERABLY LOWER THAN ANTICIPATED               certificates and the rate of principal payments on    
                                                  the mortgage loans in the applicable Trust. The       
                                                  rate of principal payments includes scheduled         
                                                  payments of interest and principal, prepayments,      
                                                  liquidations due to defaults and repurchases. If      
                                                  the rate of prepayments on the mortgage loans         
                                                  related to your certificates is higher or lower       
                                                  than anticipated, the yield to maturity may be        
                                                  adversely affected. The yield on some types of        
                                                  certificates are more sensitive to variations in      
                                                  prepayments than others. For example, certificates    
                                                  that receive only payments of interest are            
                                                  especially sensitive to variations in the rate of     
                                                  prepayments. If the rate of prepayments is high or    
                                                  if a redemption or call feature of the certificates   
                                                  or the underlying mortgage loans occurs, the          
                                                  holders of such certificates may not fully recoup     
                                                  their initial investment. See 'Yield                  
                                                  Considerations' and 'Maturity, Average Life and       
                                                  Prepayment Assumptions' in this prospectus. See       
                                                  also 'Risk Factors' and 'Yield and Prepayment         
                                                  Considerations' in the prospectus supplement for      
                                                  more information concerning the prepayment risks      
                                                  pertaining to your certificates.                      

THE REDEMPTION OF THE CERTIFICATES OR THE         Your certificates may be subject to redemption or     
UNDERLYING MORTGAGE LOANS WILL AFFECT YOUR YIELD  other call features. Likewise, the underlying         
                                                  mortgage loans may be subject to a call feature       
                                                  which would result in the retirement of the           
                                                  certificates. Such an event would affect the          
                                                  average life and yield of each class of               
                                                  certificates in such series. See 'Yield               
                                                  Considerations' and 'Maturity, Average Life and       
                                                  Prepayment Assumptions' in this prospectus.           

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THE MORTGAGE POOLS* 

GENERAL                                                                         

Unless otherwise indicated in the applicable Prospectus Supplement, each
Mortgage Pool will consist entirely of either fixed- or adjustable-rate mortgage
loans (the 'Mortgage Loans') evidenced by promissory notes (the 'Mortgage       
Notes') secured by first mortgages, deeds of trust or security deeds (the       
'Mortgages') on one- to four-family residential properties or multi-family      
residential properties (the 'Mortgaged Properties'). The types of Mortgaged     
Properties securing the Mortgage Loans in each Mortgage Pool may include (a)    
owner occupied, (i) attached or detached single-family residences, including    
residences in planned unit developments, (ii) two- to four-family primary       
residences and (iii) condominiums or other attached dwelling units, (b)         
second/vacation homes and nonowner occupied residences, and (c) leasehold in the
underlying Mortgaged Property and such other types of homes or dwellings as are 
set forth in the related Prospectus Supplement. In the case of leasehold        
interests, the term of the leasehold will exceed the scheduled maturity of the  
Mortgage Loan by at least five years, unless otherwise specified in the related 
Prospectus Supplement. If specified in the applicable Prospectus Supplement, a  
Mortgage Pool may contain Mortgage Loans that, in addition to being secured by  
liens on real estate, are secured by other collateral, such as securities or    
insurance policies, owned by the related Mortgagors or are supported by         
third-party guarantees secured by collateral owned by the related guarantors. If
specified in the applicable Prospectus Supplement, a Mortgage Pool may contain  
cooperative apartment loans ('Cooperative Loans') evidenced by promissory notes 
('Cooperative Notes') secured by security interests in shares issued by private 
cooperative housing corporations (each, a 'Cooperative') and in the related     
proprietary leases or occupancy agreements granting exclusive rights to occupy  
specific dwelling units in the related buildings. As used herein, unless the    
context indicates otherwise, 'Mortgage Loans' includes Cooperative Loans,       
'Mortgaged Properties' includes shares in the related Cooperative and the       
related proprietary leases or occupancy agreements securing Cooperative Notes,  
'Mortgage Notes' includes Cooperative Notes and 'Mortgages' includes a security 
agreement with respect to a Cooperative Note.                                   

   The Mortgage Loans to be purchased by Washington Mutual Mortgage Securities
Corp. (the 'Company') for inclusion in a Mortgage Pool will be screened and     
underwritten in accordance with the standards set forth herein under 'The       
Company -- Mortgage Purchase Program' and ' -- Credit, Appraisal and            
Underwriting Standards'. The Mortgage Loans in each Mortgage Pool will be       
originated by or purchased from lending institutions which meet the requirements
set forth under 'The Company -- Mortgage Purchase Program' (such institutions,  
'Sellers'). Generally, with respect to each Series, the Company, another entity 
set forth in the related Prospectus Supplement (who will generally be a Seller) 
(a 'Servicing Entity') or the Company together with such Servicing Entity will  
be responsible for the servicing and administration of the Mortgage Loans (in   
such capacity, each of the Company and/or such Servicing Entity, a 'Master      
Servicer') and the Sellers will perform certain servicing functions with respect
to the Mortgage Loans (in such capacity, 'Seller/Servicers'), which term        
includes related servicing corporations, agents and replacement servicers       
designated by the Company. In the event that both the Company and a Servicing   
Entity are acting as Master Servicers with respect to a single Series, (i) each 
of the Company and such Servicing Entity will act as Master Servicer only for a 
specific group or groups of Mortgage Loans in the related Mortgage Pool (a      
'Mortgage Loan Servicing Group') as set forth in the related Prospectus         
Supplement, (ii) the duties, obligations and liabilities of each the Company and
such Servicing Entity shall relate only to its respective Mortgage Loan         
Servicing Group, and (iii) the Company, unless otherwise specified in the       
related Prospectus Supplement, will calculate amounts distributable to the      
Certificateholders, prepare tax returns on behalf of the Trust and provide      
certain other services specified in the Pooling Agreement (in such capacity, the
'Certificate Administrator'). Unless otherwise specified in the related         
Prospectus Supplement, in the event that a Servicing Entity is the only Master  
Servicer with                                                                   

---------                                                                       
* Whenever in this Prospectus the terms 'Mortgage Pool', 'Certificates' and     
'Trust' are used, those terms apply, unless the context indicates otherwise, to 
one specific Mortgage Pool, to the Series of Certificates representing undivided
interests in the assets of the related Trust and to the related Trust,          
respectively. Similarly, the term 'Certificate Interest Rate' will refer to the 
rate of interest borne by the Certificates of one specific Series (or borne by  
one Class of Certificates of one specific Series).                              

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respect to any Series, such Servicing Entity will be the Certificate            
Administrator with respect to such Series. If so specified in the applicable    
Prospectus Supplement, however, (i) the servicing of the Mortgage Loans will be 
performed by the Seller which sold the Mortgage Loans to the Company for        
conveyance to the Trust, or by a qualified servicer selected by the Company     
(either entity acting in such capacity, the 'Servicer'), (ii) there will not be 
a Master Servicer and (iii) the Company will act as the Certificate             
Administrator. The Servicer and the Certificate Administrator may perform their 
respective servicing and administrative responsibilities through agents or      
independent contractors, but shall not thereby be released from any of their    
obligations under the Pooling Agreement. See 'Description of                    
Certificates -- Servicing'. The applicable Prospectus Supplement will set forth 
information respecting the number and principal amount of Mortgage Loans which  
were originated for the purpose of (a) purchasing and (b) refinancing the       
related Mortgaged Properties.                                                   

 To the extent specified in the applicable Prospectus Supplement, Mortgage
Loans with loan-to-value ratios and/or principal balances exceeding certain     
limits will be covered partially by Primary Insurance Policies. A Mortgage Pool 
may include Mortgage Loans insured by the Federal Housing Administration ('FHA')
or guaranteed by the Department of Veterans Affairs ('VA'), which loans will be 
covered by FHA insurance policies ('FHA Insurance Policies') and VA guaranties  
('VA Guaranties'), respectively. Mortgage Loans guaranteed by the VA ('VA       
Loans') may also be covered by supplemental Primary Insurance Policies. In      
addition, if specified in the applicable Prospectus Supplement, the Company or a
Servicing Entity, as applicable, as Master Servicer, the Seller or the Servicer,
as applicable, may obtain or establish one or more credit enhancements for a    
Mortgage Pool. Any such credit enhancement will be described in the applicable  
Prospectus Supplement. Such credit enhancements may be limited to one or more   
Classes of Certificates and may include, but will not necessarily be limited to,
any of the following: a Mortgage Pool Insurance Policy, a Special Hazard        
Insurance Policy, a Fraud Bond, a Bankruptcy Bond, a Letter of Credit, a Reserve
Fund, a certificate insurance policy, or any combination of the foregoing.      
Coverage of certain risks of default or loss may also be provided to a          
particular Class or Classes of Certificates by the subordination in right of    
payment of one or more Classes of Certificates of the same Series to the right  
of holders of such Class or Classes of Certificates to receive payments. See    
'Description of Credit Enhancements'.                                           

Unless otherwise specified in the related Prospectus Supplement for any 
Series of Certificates, all Mortgage Loans will be of one or more of the        
following types of Mortgage Loans of varying terms at origination:              

     (1) fully amortizing Mortgage Loans, each providing for interest (the
'Mortgage Interest Rate') at a fixed rate and level monthly payments of 
principal and interest over the term of such Mortgage Loan;             

   (2) Mortgage Loans, each with an adjustable Mortgage Interest Rate,
   which may include graduated payment Mortgage Loans and other Mortgage Loans
providing for negative amortization;                                    

    (3) Mortgage Loans with either fixed or adjustable Mortgage Interest
Rates, that do not provide for level monthly payments of principal and  
 interest and/or do not provide for amortization in full by their maturity
dates;                                                                  

     (4) fixed-rate Mortgage Loans that do not provide for amortization in
full by their maturity dates and which may at the end of their terms be 
converted by the Mortgagors to fully amortizing adjustable-rate Mortgage
Loans, provided that certain conditions are met; and                    

(5) any other type of Mortgage Loan described in the applicable 
Prospectus Supplement.                                                  

If so specified in the related Prospectus Supplement for any Series of  
Certificates, a Mortgage Pool may contain Mortgage Loans which include          
provisions whereby the Seller or a third party partially subsidizes the monthly 
payments of the Mortgagor during the initial portion of the term of the Mortgage
Loan, the difference to be made up from a fund (the 'Buydown Fund') contributed 
by the Seller or a third party at the time of origination of the Mortgage Loan  
(a 'Buydown Loan'). A Buydown Fund will be in an amount equal either to the     
discounted value or full aggregate amount of future payment subsidies. The      
applicable Prospectus Supplement or Current Report on Form 8-K will contain     
information with respect to any Buydown Loans, including information on the     
interest rate initially payable by the Mortgagor, annual increases in the       
interest rate, the length of the buydown period and the Buydown Fund.           

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The underlying assumption of buydown plans is that the income of the Mortgagor  
will increase during the buydown period as a result of normal increases in      
compensation and inflation, so that the Mortgagor will be able to meet the full 
mortgage payments at the end of the buydown period. To the extent that this     
assumption as to increased income is not correct, the possibility of defaults on
Buydown Loans is increased.                                                     

  If so specified in the related Prospectus Supplement, a Mortgage Pool will
contain Mortgage Loans (the 'Additional Collateral Loans') that are secured by  
both the related Mortgaged Property and certain additional collateral which will
consist of (i) a security interest in financial assets owned by the Mortgagor   
(which will consist of securities, insurance policies, annuities, certificates  
of deposit, cash, accounts or similar assets) and/or (ii) a third party         
guarantee (usually by a relative of the Mortgagor), which in turn is secured by 
a security interest in financial assets (as described in (i) above) or          
residential property owned by the guarantor. The collateral described in clauses
(i) and (ii) above is referred to as 'Additional Collateral'. The amount of     
Additional Collateral for any Mortgage Loan generally will not exceed 30% of the
principal amount of such Mortgage Loan (the 'Additional Collateral              
Requirement'), and the requirement to maintain Additional Collateral will       
generally terminate when the Loan-to-Value Ratio of the Mortgage Loan is reduced
to a predetermined level (which generally shall not be more than 75%) as a      
result of a reduction in the loan amount caused by principal payments by the    
Mortgagor or an increase in the appraised value of the related Mortgaged        
Property. The Servicer of the Additional Collateral Loan will be required, in   
accordance with the Master Servicer's servicing guidelines or its normal        
servicing procedures, to attempt to realize on any such Additional Collateral,  
in addition to the related Mortgaged Property, if such Additional Collateral    
Loan is liquidated upon default. The right to receive proceeds from the         
realization of Additional Collateral upon any such liquidation will be assigned 
to the related Trust. No assurance can be given as to the amount of proceeds, if
any, that might be realized on the Additional Collateral Loan from such         
Additional Collateral and thereafter remitted to the Trust. If so specified in  
the related Prospectus Supplement, Ambac Assurance Corporation or another       
insurance company will have issued a limited purpose surety bond insuring any   
deficiency in the amounts realized from the liquidation of Additional           
Collateral, up to the amount of the Additional Collateral Requirement. For      
additional considerations concerning the Additional Collateral Loans, see       
'Certain Legal Aspects of Mortgage Loans and Contracts -- The Mortgage          
Loans -- Anti-Deficiency Legislation and Other Limitations on Lenders' herein.  

    The aggregate principal balances of the Mortgage Loans in each Mortgage Pool
on the date specified in the related Prospectus Supplement as the Cut-Off Date  
will be at least $5,000,000. Unless otherwise specified in the Prospectus       
Supplement of a particular Series, each Mortgage Loan will have an outstanding  
principal balance of not less than $30,000 nor more than $1,000,000. With       
respect to each Mortgage Pool, unless otherwise specified in the related        
Prospectus Supplement, all principal and interest payments on the Mortgage Loans
due prior to the Cut-Off Date will have been made.                              

For each Mortgage Pool, the related Prospectus Supplement will generally
contain specific information as of the Cut-Off Date regarding (i) the aggregate 
principal balance of the Mortgage Loans; (ii) the range of Mortgage Interest    
Rates or initial Mortgage Interest Rates borne by the Mortgage Loans; (iii) the 
year in which the first monthly payments occur, and the latest maturity of the  
Mortgage Loans; (iv) the range of principal balances of the Mortgage Loans at   
origination; (v) the aggregate principal balance of all Mortgage Loans having   
loan-to-value ratios at origination exceeding 80%; (vi) the types of dwellings  
constituting the Mortgaged Properties securing the Mortgage Loans; (vii) the    
percentage of the Mortgage Loans (by principal balance) of nonowner occupied and
of second or vacation properties; (viii) the geographic distribution of the     
Mortgage Loans, prepared on a state-by-state basis for states containing 5% or  
more of the Mortgage Pool; and (ix) the number and aggregate principal balance  
of Buydown Loans.                                                               

Specific information with respect to the Mortgage Loans in a particular 
Mortgage Pool and the applicable credit enhancements which is not included in   
the related Prospectus Supplement will generally be included in a Current Report
on Form 8-K which will be available to purchasers of the Certificates at or     
before the time of initial issuance of the related Series of Certificates, and  
which will be filed with the Securities and Exchange Commission (the            
'Commission') within 15 days thereafter.                                        

 The Company and/or a Servicing Entity, as applicable, as Master Servicer,
has entered or will enter into a contract with each related Seller/Servicer to  
perform, as an independent contractor, certain servicing functions for such     
Master Servicer subject to its supervision and may enter into a contract with an

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independent entity to perform administration functions for the Mortgage Pools   
(or, if applicable, the Mortgage Loan Servicing Group), subject to such Master  
Servicer's supervision. Unless otherwise specified in the applicable Prospectus 
Supplement, such Master Servicer will reserve the right to remove any related   
Seller/Servicer of any Mortgage Loan at any time if such Master Servicer        
considers such removal to be in the best interests of Certificateholders. In    
such event, such Master Servicer would continue to be responsible for servicing 
such Mortgage Loan and may designate a replacement Seller/Servicer (which may   
include the Company or the related Servicing Entity, as applicable, or an       
affiliate of the Company or Servicing Entity, as applicable). Each Master       
Servicer may perform its administrative and servicing responsibilities through  
agents or independent contractors, but shall not thereby be released from any of
its responsibilities under the Pooling Agreement. Each Master Servicer will     
receive a fee (the 'Master Servicing Fee') for its services. In the event that  
both the Company and a Servicing Entity are acting as Master Servicers for a    
Series, unless otherwise specified in the related Prospectus Supplement, the    
Master Servicing Fee for each of the Company and such Servicing Entity will only
relate to its respective Mortgage Loan Servicing Group. The Seller/Servicers    
will perform certain servicing functions for the Company pursuant to servicing  
contracts (the 'Servicing Contracts') with a Master Servicer and will receive a 
fee for acting as the primary servicer of the related Mortgage Loans (the       
'Servicing Fee'). The fees to a Master Servicer and the Seller/Servicers will be
paid from the difference between the Mortgage Interest Rates on each Mortgage   
Loan (or Mortgage Loan Servicing Group, if applicable) and the Pass-Through Rate
with respect to such Mortgage Loan.                                             

 If so specified in the applicable Prospectus Supplement, there will be no
Master Servicer for a particular Series of Certificates. In such event, (i) the 
servicing of the Mortgage Loans will be performed by the Servicer specified in  
the applicable Prospectus Supplement, (ii) there will not be a Master Servicer, 
and (iii) the Certificate Administrator will calculate amounts distributable to 
the Certificateholders, prepare tax returns on behalf of the Trust and provide  
certain other administrative services specified in the Pooling Agreement. The   
Servicer and the Certificate Administrator may perform their respective         
servicing and administrative responsibilities through agents or independent     
contractors, but shall not thereby be released from any of their respective     
responsibilities under the Pooling Agreement. With respect to such Series of    
Certificates, the Servicer will receive the Servicing Fee and, with respect to  
each such Series and each Series in which both the Company and a Servicing      
Entity are acting as Master Servicers, the Certificate Administrator will       
receive a fee for its services (the 'Certificate Administrator Fee'), each of   
which will be paid from the difference between the Mortgage Interest Rate on    
each Mortgage Loan and the Pass-Through Rate with respect to such Mortgage Loan.

Unless otherwise specified in the applicable Prospectus Supplement, the 
Certificates of each Series will represent undivided interests in the assets of 
a trust (the 'Trust') consisting of the Mortgage Loans included in the Mortgage 
Pool for that Series and related property. Certain Series will be enhanced by   
mortgage loan insurance or other forms of credit enhancement, in each case as   
more fully described herein under the captions 'Description of Certificates' and
'Description of Credit Enhancements' and/or in the related Prospectus           
Supplement. When each Series of Certificates is issued, the Company will cause  
the Mortgage Loans in the Mortgage Pool for that Series to be assigned to the   
Trust. An independent bank or trust company will act as trustee (the 'Trustee') 
for the benefit of the holders of Certificates of that Series, and the Master   
Servicer or the Servicer will be responsible for servicing the Mortgage Loans   
pursuant to a separate pooling and servicing agreement ('Pooling Agreement') for
the Series.                                                                     

   The Company's assignment of the Mortgage Loans to the Trust will be without
recourse, and the Company's obligations with respect to the Mortgage Loans will,
unless otherwise indicated in the Prospectus Supplement for a Series of         
Certificates, be limited to any representations and warranties made by it in, as
well as its contractual obligations under, the Pooling Agreement for each       
Series. These obligations consist primarily of the obligation to administer and,
if applicable, service the Mortgage Loans. With respect to Series of            
Certificates as to which the Company and/or a Servicing Entity will act as      
Master Servicer and unless otherwise stated in the Prospectus Supplement for    
such Series, in the event of delinquencies in payments on the Mortgage Loans in 
any Mortgage Pool (or the related Mortgage Loan Servicing Group for such Series 
if both the Company and a Servicing Entity are acting as Master Servicers), to  
advance cash ('Advances') in the amounts described herein under 'Description of 
Certificates -- Advances', to the extent such Advances are not made by the      
Seller/Servicers and, if the Company and a Servicing Entity are acting as Master
Servicers for such Series, to the extent that such                              

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Advances relate to a Mortgage Loan in their respective Mortgage Loan Servicing  
Group. Any such Advances by a Master Servicer will be limited to amounts which, 
in the judgment of such Master Servicer, ultimately will be reimbursable with   
respect to such Mortgage Pool (or the related Mortgage Loan Servicing Group for 
such Series if both the Company and a Servicing Entity are acting as Master     
Servicers) from Mortgagor payments or under any applicable Mortgage Pool        
Insurance Policy, any applicable Special Hazard Insurance Policy, any Primary   
Insurance Policy, FHA Insurance Policy or VA Guaranty issued with respect to a  
Mortgage Loan, any applicable Letter of Credit, Reserve Fund or any other       
applicable policy of insurance, any subordination feature described herein or   
the proceeds of liquidation of a Mortgage Loan. See 'Description of Credit      
Enhancements'. Unless otherwise specified in the applicable Prospectus          
Supplement, each Seller/Servicer will be obligated, in the event of             
delinquencies on the Mortgage Loans serviced by it in any Mortgage Pool, to make
Advances limited to amounts which, in its judgment, after consultation with the 
Master Servicer (or the related Master Servicer if both the Company and a       
Servicing Entity are acting as Master Servicers), ultimately will be            
reimbursable from the sources stated above. If so specified in the applicable   
Prospectus Supplement, neither a Master Servicer nor any Seller/Servicers will  
be obligated to make Advances with respect to Mortgage Loans delinquent longer  
than the time period specified in such Prospectus Supplement. See 'Description  
of Certificates -- Advances' and 'Description of Credit Enhancements'. A Master 
Servicer is obligated to remit to Certificateholders of a Series all amounts    
relating to the Mortgage Loans (or the related Mortgage Loan Servicing Group for
such Series if both the Company and a Servicing Entity are acting as Master     
Servicers) to the extent such amounts have been collected or advanced by the    
Seller/Servicers or advanced by such Master Servicer and are due                
Certificateholders pursuant to the terms of the Pooling Agreement for such      
Series. With respect to Series of Certificates as to which there will be no     
Master Servicer and the servicing of the Mortgage Loans will be performed by the
Servicer, unless otherwise stated in the applicable Prospectus Supplement, the  
Servicer will be obligated to make Advances in the amounts described herein     
under 'Description of Certificates -- Advances', limited to amounts which, in   
the judgment of the Servicer, ultimately will be reimbursable with respect to   
such Mortgage Pool from any of the sources stated above.                        

CONVERSION OF MORTGAGE LOANS                                                    

 The Prospectus Supplement for certain Series of Certificates representing
undivided interests in the assets of a Trust consisting of adjustable-rate      
Mortgage Loans may provide that some or all of the Mortgage Loans in the related
Mortgage Pool may have a conversion feature. Unless otherwise specified in the  
related Prospectus Supplement, each such Mortgage Loan may be converted at the  
Mortgagor's option at any time during a specified initial period to a fixed-rate
Mortgage Loan, subject to the Seller/Servicer's or the Servicer's determination 
that the Mortgagor has met certain payment history requirements and the payment 
of a conversion fee ('Conversion Fee') to the Seller/Servicer or the Servicer,  
as applicable. Unless otherwise specified in the applicable Prospectus          
Supplement, upon any such conversion, the Company or the Servicing Entity, as   
applicable, as Master Servicer, or the Seller with respect to Series of         
Certificates as to which there will be no Master Servicer, will repurchase the  
Mortgage Loan from the Mortgage Pool at its then outstanding principal balance, 
plus interest at the Mortgage Interest Rate on such Mortgage Loan to the date of
repurchase. The amounts distributable to Certificateholders of different        
Classes, if applicable, upon such repurchase, and the portion of the Conversion 
Fee to be passed through to Certificateholders, if any, will be set forth in the
Prospectus Supplement for each such Series of Certificates.                     

USE OF PROCEEDS 

  All of the net proceeds to be received from the sale of each Series of the
Certificates will be used by the Company to purchase the Mortgage Loans related 
to that Series or to return to the Company the amounts previously used to effect
such purchases, the costs of carrying the Mortgage Loans until sale of the      
Certificates and other expenses connected with pooling the Mortgage Loans and   
issuing the Certificates, or for general corporate purposes. The Company expects
to issue Certificates in Series from time to time as part of its continuing     
program of acquiring Mortgage Loans and selling Certificates. See 'The          
Company -- Mortgage Purchase Program'.                                          

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YIELD CONSIDERATIONS

GENERAL                                                                         

  The yield to maturity on any Certificate will depend on the purchase price
paid by the Certificateholder, the effective interest rate of the Certificate   
and the weighted average life of the Mortgage Loans underlying the Certificate. 
See 'Maturity, Average Life and Prepayment Assumptions' for a discussion of     
weighted average life. Any prepayment of a Mortgage Loan, liquidation of a      
Mortgage Loan (by foreclosure proceedings or by virtue of the purchase of a     
Mortgage Loan in advance of its stated maturity or otherwise) or, if applicable,
the occurrence of a redemption or other call feature of the Certificates of a   
Series or the underlying Mortgage Loans will have the effect of passing through 
to Certificateholders amounts of principal which would otherwise be passed      
through in amortized increments over the remaining term of such Mortgage Loan.  
The effect of such prepayments on the yield to maturity to Certificateholders   
depends on several factors. For example, if the Certificates are purchased above
par (i.e., for more than 100% of the outstanding principal balance of the       
Mortgage Loans they represent), such prepayments will tend to decrease the yield
to maturity. If the Certificates were purchased at a discount (i.e., for less   
than 100% of such outstanding principal balance), such prepayments will tend to 
increase the yield to maturity. See 'Certain Legal Aspects of the Mortgage      
Loans -- Enforceability of Certain Provisions' for a description of certain     
provisions of each Mortgage Loan and statutory, regulatory and judicial         
developments that may affect the prepayment experience and maturity assumptions 
on the Mortgage Loans. See also 'Description of Certificates -- Termination' for
a description of the repurchase of the Mortgage Loans in any Mortgage Pool when 
the aggregate outstanding principal balance thereof is less than a specified    
percentage of the aggregate outstanding principal balance of the Mortgage Loans 
in such Mortgage Pool on the related Cut-Off Date.                              

    The timing of changes in the rate of principal payments on or repurchases of
the Mortgage Loans (including, if applicable, the occurrence of a redemption or 
other call feature of the Certificates of a Series or the underlying Mortgage   
Loans) may significantly affect an investor's actual yield to maturity, even if 
the average rate of principal payments experienced over time is consistent with 
an investor's expectation. In general, the earlier a prepayment of principal on 
the underlying Mortgage Loans or a repurchase thereof (including, if applicable,
the occurrence of a redemption or other call feature of the Certificates of a   
Series or the underlying Mortgage Loans), the greater will be the effect on an  
investor's yield to maturity. As a result, the effect on an investor's yield to 
maturity of principal payments and repurchases occurring at a rate higher (or   
lower) than the rate anticipated by the investor during the period immediately  
following the issuance of a Series of Certificates would not be fully offset by 
a subsequent like reduction (or increase) in the rate of principal payments.    

EFFECTIVE INTEREST RATE                                                         

Unless otherwise specified in the applicable Prospectus Supplement, each
monthly interest payment on a Mortgage Loan is calculated as 1/12 of the        
applicable Mortgage Interest Rate multiplied by the unpaid principal balance    
outstanding on the first day of the month after application of principal        
payments made on such date. Unless otherwise specified in the applicable        
Prospectus Supplement, the Certificate Interest Rate for each Class of          
Certificates will be calculated on the basis of the 'Pass-Through Rate' for the 
related Mortgage Loans. With respect to a Series of Certificates as to which the
Company will act as Master Servicer, the 'Pass-Through Rate' for any Mortgage   
Loan will equal the related Mortgage Interest Rate less the sum of the Servicing
Fee and the Master Servicing Fee for such Mortgage Loan. With respect to a      
Series of Certificates as to which the Company will not act as Master Servicer, 
the 'Pass-Through Rate' for any Mortgage Loan will equal the related Mortgage   
Interest Rate less the sum of the Servicing Fee and the Certificate             
Administrator Fee for such Mortgage Loan.                                       

   As described in the applicable Prospectus Supplement, in certain events, if
the amounts available for distribution in respect of interest are not sufficient
to cover the total of all accrued and unpaid interest at the Pass-Through Rate, 
the available amount will be distributed to the Certificateholders pro rata in  
accordance with their respective interests or in an order of priority described 
in the applicable Prospectus Supplement.                                        

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For the sale of Certificates under this Prospectus, the Company may     
establish one or more Mortgage Pools having a variable, as opposed to a fixed,  
Pass-Through Rate. A Mortgage Pool with a variable Pass-Through Rate may be     
composed of Mortgage Loans that have adjustable Mortgage Interest Rates, or of  
Mortgage Loans with fixed Mortgage Interest Rates if the amount to be passed    
through is determined on a Mortgage Loan-by-Mortgage Loan basis as the Mortgage 
Interest Rate minus specified fees for servicing and administrative             
compensation, which may include any of the Servicing Fee, the Master Servicing  
Fee and the Certificate Administrator Fee, for each such Mortgage Loan, as set  
forth in the Prospectus Supplement, or as otherwise determined as described in  
the applicable Prospectus Supplement. Because the Mortgage Interest Rates may   
vary in such a Mortgage Pool, and the servicing and administrative compensation 
generally will be fixed, the Pass-Through Rate will be affected by              
disproportionate principal prepayments among Mortgage Loans bearing different   
Mortgage Interest Rates and, consequently, the yield to maturity                
Certificateholders will be affected. The characteristics of any such            
variable-rate Mortgage Pools will be described in the applicable Prospectus     
Supplement. Although Mortgage Interest Rates in a fixed Pass-Through Rate       
Mortgage Pool may vary from Mortgage Loan to Mortgage Loan, disproportionate    
principal prepayments among the Mortgage Loans bearing different Mortgage       
Interest Rates will not affect the return to Certificateholders.                

For any Series of Certificates, the effective yield to maturity to      
Certificateholders generally will be slightly lower than the yield to maturity  
otherwise produced by the applicable Pass-Through Rate because, while interest  
will accrue on each Mortgage Loan from the first day of each month, the         
distribution of such interest to Certificateholders at the applicable           
Pass-Through Rate generally will be made on a later day, which, unless otherwise
specified in the applicable Prospectus Supplement, will be the 25th day (or, if 
such day is not a business day, the next succeeding business day) of the month  
following the month of accrual.                                                 

   When a prepayment in full (a 'Payoff') is made by a Mortgagor on a Mortgage
Loan during a month, the Mortgagor is charged interest on the days in the month 
actually elapsed up to the date of the Payoff at the daily interest rate        
(determined by dividing the Mortgage Interest Rate by 365, or 360 in the case of
Payoffs received on a date on which the monthly payment for such Mortgage Loan  
is due (a 'Due Date')) which is applied to the principal amount of the Mortgage 
Loan so prepaid. Similarly, when a Mortgage Loan is liquidated under a Mortgage 
Pool Insurance Policy during a month, the pool insurer will pay interest on the 
Mortgage Loan only to the date the claim is paid. Also, when a partial principal
prepayment (a 'Curtailment') is made on a Mortgage Loan together with the       
scheduled Monthly Payment for a month on or after the related Due Date, the     
Mortgagor does not pay interest on the prepaid amount, and therefore            
Certificateholders will not receive any interest on such prepaid amount.        

  Unless otherwise specified in the applicable Prospectus Supplement, to the
extent that Compensating Interest (as defined below) is not paid, the effect of 
a Payoff or such a liquidation will be to reduce slightly the amount of interest
passed through on the next Distribution Date, because interest on the principal 
amount of the Mortgage Loan so prepaid was paid only to the date of such Payoff 
or liquidation and not to the end of the month of prepayment. Unless otherwise  
specified in the applicable Prospectus Supplement, the following will apply:    
Payoffs received during the period from the first day of a calendar month       
through the 14th day of such month will be passed through, without Compensating 
Interest and without interest accrued from the first day of such month to the   
date of the Payoff, on the Distribution Date in such month, and Payoffs received
during the period from the 15th day of a calendar month through the last day of 
such month will be passed through, with Compensating Interest and with interest 
at the applicable Pass-Through Rate attributable to interest paid through the   
date of the Payoff by the Mortgagors on the Distribution Date in the following  
month. Proceeds of Mortgage Loans liquidated under a Mortgage Pool Insurance    
Policy during a month will be passed through, with Compensating Interest and    
interest at the applicable Pass-Through Rate attributable to interest paid by   
the pool insurer under an applicable Mortgage Pool Insurance Policy, on the     
Distribution Date in the following month.                                       

Unless otherwise specified in the applicable Prospectus Supplement, the 
following will apply: 'Compensating Interest' will consist of a full month's    
payment of interest at the applicable Pass-Through Rate on a Mortgage Loan for  
which a Payoff is made or which is liquidated, less the interest at the         
applicable Pass-Through Rate attributable to interest paid by the Mortgagor or  
by the pool insurer under an applicable Mortgage Pool Insurance Policy through  
the date of Payoff. Compensating Interest on                                    

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liquidated Mortgage Loans will be passed through to Certificateholders, together
with any interest at the applicable Pass-Through Rate attributable to interest  
paid by the pool insurer under any applicable Mortgage Pool Insurance Policy to 
the date of liquidation on the Distribution Date of the month following         
liquidation. Compensating Interest on Payoffs will be paid on a Distribution    
Date only with respect to Payoffs received during the period from the 15th day  
of the preceding calendar month through the last day of such preceding month.   
The applicable Pooling and Servicing Agreement will specify any limitations on  
the extent of or source of funds available for payments of Compensating         
Interest.                                                                       

MATURITY, AVERAGE LIFE AND PREPAYMENT ASSUMPTIONS 

    The Mortgage Loans at origination will have varying maturities as more fully
described in the applicable Prospectus Supplement. The Company expects that most
such Mortgage Loans will have maturities at origination of either 10 to 15 years
or 20 to 30 years and that such Mortgage Loans may be prepaid in full or in part
at any time, generally without penalty. The prepayment experience or, if        
applicable, the occurrence of a redemption or other call feature of the         
Certificates of a Series or the underlying Mortgage Loans will affect the lives 
of the Certificates. The Company anticipates that a substantial number of       
Mortgage Loans will be paid in full prior to their scheduled maturity.          

A number of factors, including homeowner mobility, economic conditions, 
enforceability of 'due-on-sale' clauses, assumability of the Mortgage Loans,    
mortgage market interest rates and the general availability of mortgage funds   
affect prepayment experience. Generally, each Mortgage executed in connection   
with a fixed-rate Mortgage Loan, except for FHA-insured or VA-guaranteed        
Mortgage Loans, will contain 'due-on-sale' provisions permitting the holder of  
the Mortgage Note to accelerate the maturity of the Mortgage Loan upon          
conveyance by the Mortgagor of the underlying Mortgaged Property. With respect  
to Series of Certificates as to which the Company will act as Master Servicer,  
the Master Servicer will agree that it or the applicable Seller/Servicer will   
enforce any 'due-on-sale' clause contained in any such Mortgage to the extent it
has knowledge of the conveyance or proposed conveyance of the underlying        
Mortgaged Property and reasonably believes that it is entitled to do so under   
applicable law; provided, however, that neither the Master Servicer nor the     
Seller/Servicer will take any action in relation to the enforcement of any      
'due-on-sale' provision which would impair or threaten to impair any recovery   
under any related Primary Insurance Policy or Mortgage Pool Insurance Policy.   
With respect to Series of Certificates as to which the Company will not act as  
Master Servicer, the Servicer will agree to enforce any 'due-on-sale' clause in 
the instances and to the extent described in the preceding sentence. However, a 
Mortgage Pool may contain fixed-rate Mortgage Loans which will allow a          
subsequent owner of a Mortgaged Property, if credit underwriting standards are  
met, to assume such fixed-rate Mortgage Loan without enforcement of any         
'due-on-sale' clause. With respect to Mortgage Loans bearing adjustable Mortgage
Interest Rates, unless otherwise specified in the related Prospectus Supplement,
the related Mortgages will generally provide that such Mortgage Loans are       
assumable by creditworthy subsequent owners without enforcement of any          
'due-on-sale' clause. An assumption of a Mortgage Loan may have the effect of   
increasing the life of such Mortgage Loan.                                      

'Weighted average life' refers to the average amount of time that will  
elapse from the date of issuance of a Certificate until each dollar of principal
will be repaid to the Certificateholders. The weighted average life of the      
Certificates will be influenced by the rate at which principal on the Mortgage  
Loans in the Mortgage Pool is paid, which may be in the form of (i) scheduled   
amortization or (ii) Curtailments and Payoffs (collectively 'Principal          
Prepayments'). Based upon published information, the rate of prepayments on     
fixed- and adjustable-rate conventional one- to four-family mortgage loans has  
fluctuated significantly in recent years. The Company believes such fluctuation 
is due to a number of factors, including those discussed above, and that such   
factors will also affect the prepayment experience on the Mortgage Loans in any 
Mortgage Pool. Accordingly, the Company cannot predict what future prepayment   
experience will be or what the resulting weighted average life might be.        
However, principal prepayments on mortgage loans are commonly measured relative 
to a prepayment standard or model. The model used in this Prospectus and in each
Prospectus Supplement, unless otherwise indicated therein (the 'Basic Prepayment
Assumption' or 'BPA'), represents an assumed rate of prepayment each month      
relative to the then outstanding principal balance of a pool of new Mortgage    
Loans. The BPA assumes prepayment rates of 0.2% per annum of the then           
outstanding principal balance of such Mortgage Loans in the first               

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month of the life of the Mortgage Loans and an additional 0.2% per annum in each
month thereafter until the 30th month. Beginning in the 30th month and in each  
month thereafter during the life of the Mortgage Loans, such prepayment model   
assumes a constant prepayment rate of 6.0% per annum. Varying prepayment        
assumptions are often expressed as percentages of the BPA (e.g., at 150% of the 
BPA, assumed prepayments during the first month of a pool would be 0.3% per     
annum, each month thereafter the rate of prepayments would increase by 0.3% per 
annum, and in the 30th and succeeding months the rate would be 9% per annum).   
The Prospectus Supplement or Current Report on Form 8-K for each Series of      
Certificates may contain a table setting forth the projected weighted average   
life of each Class of Certificates of such Series and the percentage of the     
original principal amounts or notional principal amounts of each such Class that
would be outstanding on specified Distribution Dates for such Series, based on  
the assumptions set forth with respect to the BPA deemed appropriate by the     
Company and specified therein.                                                  

REDEMPTION OF CERTIFICATES OR UNDERLYING MORTGAGE LOANS                         

   If so specified in the Prospectus Supplement for a Series, the Certificates
of such Series or the underlying Mortgage Loans may be subject to redemption at 
the direction of the holder of certain redemption rights, beginning on the      
Distribution Date and subject to payment of the redemption price and other      
conditions specified in the related Prospectus Supplement. A redemption would   
result in the concurrent retirement of all outstanding Certificates of the      
Series and would decrease the average lives of such Certificates, perhaps       
significantly. The earlier after the Closing Date that a redemption occurs, the 
greater would be such effect. In general, a redemption is most likely to occur  
if prevailing interest rates have declined. The holder of the redemption right  
may also be a Holder of one or more Classes of the related Series, which may    
affect such holder's decision whether to direct a redemption. The effect of a   
redemption of the Certificates or underlying Mortgage Loans on interest payments
on the Classes of Certificates of a Series will be described in the related     
Prospectus Supplement. See 'Description of the Certificates -- Redemption       
Agreement' and 'The Mortgage Pools -- General'.                                 

THE COMPANY 

  The Company, a Delaware corporation, is a wholly-owned indirect subsidiary
of Washington Mutual, Inc., a savings and loan holding company. The Company was 
organized for the purpose of providing mortgage lending institutions, including 
affiliated institutions, with greater financing and lending flexibility by      
purchasing mortgage loans from such institutions and issuing mortgage-backed    
securities. The Company's principal executive offices are located at 1201 Third 
Avenue, WMT 1706, Seattle, Washington 98101, telephone 206-377-8555.            

MORTGAGE PURCHASE PROGRAM                                                       

  Set forth below is a description of the principal aspects of the Company's
purchase program for Mortgage Loans eligible for inclusion in a Mortgage Pool.  
The Company will represent and warrant to the Trust that each Mortgage Pool will
consist of Mortgage Loans purchased from one or more institutions ('Sellers')   
which are (i) state-chartered or federally-chartered savings and loan           
associations, banks or similar financial institutions whose deposits or accounts
are insured by the Federal Deposit Insurance Corporation ('FDIC') or, if        
specified in the applicable Prospectus Supplement or Current Report on Form 8-K,
substantially similar deposit insurance approved by any applicable rating       
agency, (ii) approved as mortgagees by the FHA ('FHA-Approved Mortgagees'),     
(iii) approved by Fannie Mae as mortgagees ('Fannie Mae Approved Mortgagees') or
by Freddie Mac as mortgagees ('Freddie Mac Approved Mortgagees'), or any        
successor entity to either, (iv) assignees of FHA-Approved Mortgagees, Fannie   
Mae Approved Mortgagees or Freddie Mac Approved Mortgagees, (v) the FDIC,       
(vi) entities which have purchased Mortgage Loans from institutions described in
clauses (i)-(v) above or (vii) such other entities as may be described in the   
applicable Prospectus Supplement. The institutions described in clauses (i)-(v) 
of the preceding sentence will collectively be referred to herein as 'Lenders'. 
The Company has approved (or will approve) individual institutions as eligible  
Lenders by applying certain criteria, including the Lender's depth of mortgage  
origination experience, servicing experience and financial stability. In        
general, each Lender must have experience in originating and servicing          
conventional residential mortgages and must have a net worth acceptable to the  
Company. Each Lender is required to use the services of qualified               

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underwriters, appraisers and attorneys. Other factors evaluated by the Company  
in approving Lenders include delinquency and foreclosure ratio performances.    

LOAN STANDARDS                                                                  

  The Mortgage Loans to be included in each Mortgage Pool will be loans with
fixed or adjustable rates of interest secured by first mortgages, deeds of trust
or security deeds on residential properties with original principal balances    
which generally did not exceed 95% of the value of the Mortgaged Properties,    
unless such loans are FHA-insured or VA-guaranteed. Generally, each Mortgage    
Loan having a loan-to-value ratio at origination and as of the Cut-Off Date in  
excess of 80% or which is secured by a second or vacation home will be covered  
by a Primary Insurance Policy, FHA Insurance Policy or VA Guaranty insuring     
against default all or a specified portion of the principal amount thereof. See 
'Primary Insurance, FHA Mortgage Insurance, VA Mortgage Guaranty, Hazard        
Insurance; Claims Thereunder'. Each mortgage insurer must be a Qualified Insurer
(defined herein to mean a mortgage guaranty insurance company which is duly     
qualified as such under the laws of each state in which the Mortgaged Properties
are located, duly authorized and licensed in such states to transact a mortgage 
guaranty insurance business and to write the insurance provided by the Primary  
Insurance Policy or the Mortgage Pool Insurance Policy, as the case may be, and 
which is approved as an insurer by Freddie Mac, Fannie Mae or any successor     
entity to either, and by the Company).                                          

The Mortgage Loans to be included in each Mortgage Pool will be 'one- to
four-family' mortgage loans, which means permanent loans (as opposed to         
construction or land development loans) secured by Mortgages on non-farm        
properties, including attached or detached single-family or second/vacation     
homes, two- to four-family primary residences and condominiums or other attached
dwelling units, including individual condominiums, row houses, townhouses and   
other separate dwelling units even when located in buildings containing five or 
more such units. Each Mortgage Loan must be secured by an owner occupied primary
residence or second/vacation home, or by a nonowner occupied residence. The     
Mortgaged Property may not be a mobile home.                                    

CREDIT, APPRAISAL AND UNDERWRITING STANDARDS                                    

  The Mortgage Loans to be included in each Mortgage Pool will be subject to
the various credit, appraisal and underwriting standards described herein. The  
Company's credit, appraisal and underwriting standards with respect to certain  
Mortgage Loans will generally conform to those published in the Company's       
Selling Guide (together with the Company's Servicing Guide, the 'Guide', as     
modified from time to time). The credit, appraisal and underwriting standards as
set forth in the Guide are continuously revised based on opportunities and      
prevailing conditions in the residential mortgage market and the market for the 
Company's mortgage pass-through certificates. The Mortgage Loans may be         
underwritten by the Company or by designated third parties.                     

    In addition, the Company may purchase Mortgage Loans which do not conform to
the underwriting standards set forth in the Guide. Such Mortgage Loans may be   
purchased in negotiated transactions from Sellers who will represent that the   
Mortgage Loans have been originated in accordance with credit, appraisal and    
underwriting standards agreed to by the Company. The Company will generally     
review only a limited portion of the Mortgage Loans in any delivery of such     
Mortgage Loans for conformity with the applicable credit, appraisal and         
underwriting standards. Certain other Mortgage Loans will be purchased from     
Sellers who will represent that the Mortgage Loans were originated pursuant to  
credit, appraisal and underwriting standards determined by a mortgage insurance 
company acceptable to the Company. The Company will accept a certification from 
such insurance company as to a Mortgage Loan's insurability in a mortgage pool  
as of the date of certification as evidence that such Mortgage Loan conforms to 
applicable underwriting standards. Such certifications will likely have been    
issued before the purchase of the Mortgage Loans by the Company. The Company    
will perform only random quality assurance reviews on Mortgage Loans delivered  
with such certifications.                                                       

The credit, appraisal and underwriting standards utilized in negotiated 
transactions and the credit, appraisal and underwriting standards of insurance  
companies issuing certificates may vary substantially from the credit, appraisal
and underwriting standards set forth in the Guide. All of the credit, appraisal 

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and underwriting standards will provide an underwriter with sufficient          
information to evaluate the borrower's repayment ability and the adequacy of the
Mortgaged Property as collateral. Due to the variety of underwriting standards  
and review procedures that may be applicable to the Mortgage Loans included in  
any Mortgage Pool, the related Prospectus Supplement will not distinguish among 
the various credit, appraisal and underwriting standards applicable to the      
Mortgage Loans nor describe any review for compliance with applicable credit,   
appraisal and underwriting standards performed by the Company. Moreover, there  
can be no assurance that every Mortgage Loan was originated in conformity with  
the applicable credit, appraisal and underwriting standards in all material     
respects, or that the quality or performance of Mortgage Loans underwritten     
pursuant to varying standards as described above will be equivalent under all   
circumstances.                                                                  

The Company's underwriting standards are intended to evaluate the       
prospective Mortgagor's credit standing and repayment ability, and the value and
adequacy of the proposed Mortgaged Property as collateral. In the loan          
application process, prospective Mortgagors will be required to provide         
information regarding such factors as their assets, liabilities, income, credit 
history, employment history and other related items. Each prospective Mortgagor 
will also provide an authorization to apply for a credit report which summarizes
the Mortgagor's credit history. With respect to establishing the prospective    
Mortgagor's ability to make timely payments, the Company will require evidence  
regarding the Mortgagor's employment and income, and of the amount of deposits  
made to financial institutions where the Mortgagor maintains demand or savings  
accounts. In some instances, Mortgage Loans which were originated under a       
Limited Documentation Origination Program may be sold to the Company. For a     
mortgage loan originated under a Limited Documentation Origination Program to   
qualify for purchase by the Company, the prospective mortgagor must have a good 
credit history and be financially capable of making a larger cash down payment, 
in a purchase, or be willing to finance less of the appraised value, in a       
refinancing, than would otherwise be required by the Company. Currently, the    
Company's underwriting standards provide that only mortgage loans with certain  
loan-to-value ratios will qualify for purchase. If the mortgage loan qualifies, 
the Company waives some of its documentation requirements and eliminates        
verification of income and employment for the prospective mortgagor.            

   The Company's underwriting standards generally follow guidelines acceptable
to Fannie Mae and Freddie Mac. In determining the adequacy of the property as   
collateral, an independent appraisal is made of each property considered for    
financing. The appraiser is required to inspect the property and verify that it 
is in good condition and that construction, if new, has been completed. The     
appraisal is based on the appraiser's judgment of values, giving appropriate    
weight to both the market value of comparable homes and the cost of replacing   
the property.                                                                   

Certain states where the Mortgaged Properties may be located are        
'anti-deficiency' states where, in general, lenders providing credit on one- to 
four-family properties must look solely to the property for repayment in the    
event of foreclosure. See 'Certain Legal Aspects of the Mortgage Loans -- Anti- 
Deficiency Legislation and Other Limitations on Lenders'. The Company's         
underwriting standards in all states (including anti-deficiency states) require 
that the underwriting officers be satisfied that the value of the property being
financed, as indicated by the independent appraisal, currently supports and is  
anticipated to support in the future the outstanding loan balance, and provides 
sufficient value to mitigate the effects of adverse shifts in real estate       
values.                                                                         

SELLER WARRANTIES AND INDEMNIFICATION OF THE COMPANY                            

  With respect to Series of Certificates as to which the Company will be the
only Master Servicer or with respect to each Series as to which the Company and 
a Servicing Entity will act as Master Servicers, each Seller generally will make
representations and warranties with respect to Mortgage Loans or the Mortgage   
Loans in the Company's Mortgage Loan Servicing Group, respectively, sold by it  
to the Company for conveyance to the Trust which the Company deems sufficient to
permit it to make its representations and warranties in respect of such Mortgage
Loans to the Trust under the Pooling Agreement. See 'Description of             
Certificates -- Representations and Warranties' below. Each Seller will also    
make certain other representations and warranties regarding Mortgage Loans sold 
by it. Each Seller will agree to indemnify the Company against any loss or      
liability incurred by the Company on account of any breach of any representation
or warranty made by the Seller, any failure to disclose any matter that makes   

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any such representation and warranty misleading, or any inaccuracy in           
information furnished by the Seller to the Company, including any information   
set forth in this Prospectus or in any Prospectus Supplement. See 'Description  
of Certificates -- Assignment of Mortgage Loans' and ' -- Representations and   
Warranties'.                                                                    

  With respect to Series of Certificates as to which there will be no Master
Servicer, the Seller which sold the Mortgage Loans to the Company for conveyance
to the Trust will make representations and warranties to the Company with       
respect to such Mortgage Loans, and the Company will assign such representations
and warranties to the Trust under the Pooling Agreement. With respect to each   
Series of Certificates as to which a Servicing Entity will be a Master Servicer,
such Servicing Entity which sold the Mortgage Loans or the Mortgage Loan        
Servicing Group, as applicable, to the Company for conveyance to the Trust will 
make representations and warranties to the Company with respect to such Mortgage
Loans or Mortgage Loans in the related Mortgage Loan Servicing Group, as        
applicable, and the Company will assign such representations and warranties to  
the Trust under the Pooling Agreement. Upon the breach of any representation or 
warranty made by such Seller or Servicing Entity that materially and adversely  
affects the interests of the Certificateholder in a Mortgage Loan (other than   
those breaches which have been cured), the Seller or Servicing Entity will be   
required to repurchase the related Mortgage Loan. See 'Description of           
Certificates -- Assignment of Mortgage Loans' and ' -- Representations and      
Warranties'.                                                                    

RELATIONSHIPS WITH AFFILIATES                                                   

Washington Mutual Bank, an affiliate of the Company, may be a Seller, a 
Seller/Servicer or a Servicer. WaMu Capital Corp., an affiliate of the Company, 
may from time to time act as agent or underwriter in connection with the sale of
the Certificates.                                                               

DESCRIPTION OF CERTIFICATES 

 Each Series of Certificates will be issued pursuant to a separate Pooling
Agreement. With respect to Series of Certificates as to which there will be a   
Master Servicer, the Pooling Agreement will be among the Company, as Depositor  
and, if applicable, as Master Servicer, the Servicing Entity, if applicable, as 
Master Servicer, the Trustee named in the Prospectus Supplement, and, with      
respect to Series of Certificates for which the Trust will be a Delaware        
business trust, the Delaware trustee named in the Prospectus Supplement and the 
Mortgage Loans will be serviced by Seller/Servicers pursuant to selling and     
servicing contracts ('Selling and Servicing Contracts') between the Company or  
the Servicing Entity, as applicable, and such Seller/Servicers, or will be      
serviced by servicers pursuant to servicing arrangements approved by the Company
or the Servicing Entity, as applicable. With respect to Series of Certificates  
as to which there will be no Master Servicer, the Pooling Agreement will be     
among the Company, as Depositor and Certificate Administrator, the Servicer, the
Trustee named in the Prospectus Supplement, and, with respect to Series of      
Certificates for which the Trust will be a Delaware business trust, the Delaware
trustee named in the Prospectus Supplement. A form of Pooling Agreement and a   
form of the Selling and Servicing Contract are filed as exhibits to the         
Registration Statement of which this Prospectus is a part. The following        
discussion summarizes certain provisions expected to be contained in each       
Pooling Agreement which governs a Trust consisting principally of one- to       
four-family residential properties. The applicable Prospectus Supplement will   
describe material features of the related Pooling Agreement, which may differ   
from the features described below. The following summary and the summary        
contained in a Prospectus Supplement do not purport to be complete and are      
subject to, and are qualified in their entirety by reference to, all of the     
provisions of the Pooling Agreement for each particular Series and of the       
applicable Selling and Servicing Contracts or similar contracts.                

GENERAL                                                                         

 The Certificates of each Series will represent undivided interests in the
assets of a Trust created for such Series. The assets of the Trust for each     
Series will consist, to the extent provided in the Pooling Agreement, of        
(i) such Mortgage Loans as from time to time are subject to the Pooling         
Agreement (exclusive of any related Retained Yield (described below), except as 
otherwise specified in the related Prospectus Supplement), (ii) such assets as  
from time to time are held in the Certificate Account (described below) and the 
Custodial Accounts for P&I (described below) related to such Mortgage Loans     
(exclusive of any Retained Yield, except as otherwise specified in the related  
Prospectus Supplement), (iii) property acquired by foreclosure of Mortgage Loans
or deed in lieu of foreclosure, (iv) any combination,                           

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as specified in the related Prospectus Supplement, of a Letter of Credit,       
Mortgage Pool Insurance Policy, Special Hazard Insurance Policy, Bankruptcy     
Bond, Fraud Bond, Reserve Fund or other type of credit enhancement as described 
under 'Description of Credit Enhancements', (v) any private mortgage pass-      
through certificates or any certificates issued by the Freddie Mac, Fannie Mae  
or the Government National Mortgage Association described in the applicable     
Prospectus Supplement, and (vi) such other assets or rights as are described in 
the applicable Prospectus Supplement. If so specified in the applicable         
Prospectus Supplement, Certificates of a given Series may be issued in several  
Classes, which may pay interest at different rates, may represent different     
allocations of the right to receive principal and interest, and certain of which
may be subordinated to others. Any such Class of Certificates may also provide  
for payments of principal only or interest only or for disproportionate payments
of principal and interest. Subordinated Classes of a given Series of            
Certificates may or may not be offered by the same Prospectus Supplement as the 
senior Classes of such Series.                                                  

The Certificates will be freely transferable and exchangeable for       
Certificates of the same Series and Class at the office set forth in such       
Certificates, provided, however, that certain Classes of Certificates may be    
subject to transfer restrictions set forth in such Certificates and described in
the applicable Prospectus Supplement. A reasonable service charge may be imposed
for any registration of exchange or transfer of Certificates, and the Company   
may require payment of a sum sufficient to cover any tax or other governmental  
charge. If specified in the applicable Prospectus Supplement, one or more       
Classes of Certificates for any Series may be transferable only on the books of 
The Depository Trust Company or another depository identified in such Prospectus
Supplement.                                                                     

Unless otherwise indicated in the applicable Prospectus Supplement,     
beginning with the month following the month in which the Cut-Off Date occurs   
for a Series of Certificates, distributions of principal and interest (or, where
applicable, principal only or interest only) on each Class of Certificates will 
be made either by the Trustee, the Master Servicer or the Certificate           
Administrator, as applicable, acting on behalf of the Trustee or a paying agent 
appointed by the Trustee (the 'Paying Agent') on the 25th day (or if such 25th  
day is not a business day, the business day immediately following such 25th day)
of each calendar month (the 'Distribution Date') to the persons in whose names  
the Certificates are registered at the close of business on the last business   
day of the month preceding the month in which the Distribution Date occurs (the 
'Record Date'). Distributions for each Series will be made by wire transfer in  
immediately available funds for the account of, or by check mailed to, each     
Certificateholder of record; provided, however, that, unless otherwise specified
in the related Prospectus Supplement, the final distribution in retirement of   
the Certificates for each Class of a Series will be made only upon presentation 
and surrender of the Certificates at the office or agency of the Company or the 
Trustee specified in the notice to Certificateholders of such final             
distribution.                                                                   

ASSIGNMENT OF MORTGAGE LOANS                                                    

The Company will cause the Mortgage Loans to be assigned to the Trust,  
together with all principal and interest on the Mortgage Loans other than       
principal and interest due on or before the Cut-Off Date. The Company or a      
Servicing Entity, as applicable, will expressly reserve its or a Seller's rights
in and to any Retained Yield, which accordingly will not constitute assets of   
the Trust. In addition, the applicable Prospectus Supplement may specify that   
the Seller will retain the right to a specified portion of either principal or  
interest, or both. The Trustee will, concurrently with such assignment,         
authenticate and deliver the Certificates or cause the Certificates to be       
authenticated and delivered to the Company or its designated agent in exchange  
for the assets of the Trust. Each Mortgage Loan will be identified in a schedule
appearing as an exhibit to the Pooling Agreement for the related Series. Unless 
otherwise specified in the related Prospectus Supplement, such schedule will    
include information as of the close of business on the Cut-Off Date as to the   
principal balance of each Mortgage Loan, the Mortgage Interest Rate and the     
maturity of each Mortgage Note, the Seller/Servicer's or the Servicer's         
Servicing Fee and whether a Primary Insurance Policy has been obtained for each 
Mortgage Loan.                                                                  

   The Company, a Servicing Entity or a Servicer, as the case may be, will, as
to each Mortgage Loan, deliver or cause to be delivered to the Trustee the      
Mortgage Note, an assignment (except as to any Mortgage Loan registered on the  
MERS'r' System (as defined below) and unless otherwise indicated in the         
applicable Prospectus Supplement) to the Trustee or in blank of the Mortgage in 
a form for recording or                                                         

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filing as may be appropriate in the state where the Mortgaged Property is       
located, the original recorded Mortgage with evidence of recording or filing    
indicated thereon and evidence of any FHA Insurance Policy or VA Guaranty for   
such Mortgage Loan, if applicable; or, in the case of each Cooperative Loan, the
related Cooperative Note, the original security agreement, the proprietary lease
or occupancy agreement, the assignment of proprietary lease, the recognition    
agreement, the related stock certificate and related blank stock powers, and a  
copy of the original filed financing statement together with (unless otherwise  
indicated in the applicable Prospectus Supplement) assignments thereof from the 
applicable Seller to the Trustee in a form sufficient for filing. In certain    
instances where original documents respecting a Mortgage Loan may not be        
available prior to execution of the Pooling Agreement, the Company, such        
Servicing Entity or such Servicer will deliver such documents to the Trustee    
within 270 days thereafter unless, as set forth in the Pooling Agreement, the   
county recorder has not yet returned such Mortgage Loan. Notwithstanding the    
foregoing, the assets of a Trust may include Mortgage Loans where the original  
Mortgage Note is not delivered to the Trustee if the Company delivers to the    
Trustee or the custodian a copy or a duplicate original of the Mortgage Note,   
together with an affidavit certifying that the original thereof has been lost or
destroyed. With respect to such Mortgage Loans, the Trustee (or its nominee) may
not be able to enforce the Mortgage Note against the related borrower. The      
Company, such Servicing Entity or such Servicer will agree to repurchase or     
substitute for such a Mortgage Loan in certain circumstances (see 'Description  
of Certificates -- Representations and Warranties').                            

With respect to any Mortgage Loan registered on the mortgage electronic 
registration system (the 'MERS'r' System') maintained by MERSCORP, Inc. and/or  
Mortgage Electronic Registration Systems, Inc. or any successor thereto         
('MERS'), an assignment of Mortgage will not be delivered to the Trustee as     
described above, but instead the change in beneficial ownership to the Trust    
will be registered electronically through the MERS'r' System in accordance with 
the rules of membership of MERS. MERS will serve as mortgagee of record with    
respect to these Mortgage Loans solely as a nominee of the Trust, in an         
administrative capacity, and will not have any interest in these Mortgage Loans.

The Trustee will review the mortgage documents within 45 days of receipt
thereof to ascertain that all required documents have been properly executed and
received. The Trustee will hold such documents for each Series in trust for the 
benefit of Certificateholders of such Series. With respect to Series of         
Certificates as to which the Company and/or a Servicing Entity will act as      
Master Servicer, if any document is found by the Trustee not to have been       
properly executed or received or to be unrelated to the Mortgage Loans (or the  
related Mortgage Loan Servicing Group for such Series if both the Company and a 
Servicing Entity are acting as Master Servicers) identified in the Pooling      
Agreement, the Trustee will notify the Company or such Servicing Entity, as     
applicable. If the Company or such Servicing Entity, as applicable, cannot cure 
such defect, the Company or such Servicing Entity, as applicable, will          
substitute a new mortgage loan meeting the conditions set forth in the Pooling  
Agreement (see ' -- Substitution of Mortgage Loans' below) or repurchase the    
related Mortgage Loan from the Trust at a price equal to 100% of the outstanding
principal balance of such Mortgage Loan, plus accrued interest thereon at the   
applicable Pass-Through Rate through the last day of the month of such          
repurchase. With respect to Series of Certificates as to which there will be no 
Master Servicer, if a defect of the type described in the preceding sentence is 
discovered by the Trustee and cannot be cured by the Seller, the Seller will    
substitute a new mortgage loan or repurchase the related Mortgage Loan from the 
Trust upon the terms described in the preceding sentence. The purchase price of 
any Mortgage Loan so repurchased will be passed through to Certificateholders as
liquidation proceeds in accordance with the procedures specified under          
' -- Distributions on Certificates'. This substitution or repurchase obligation 
constitutes the sole remedy available to the Certificateholders or the Trust for
such a defect in a constituent document.                                        

    Buydown Funds provided by the Sellers or other parties for any Buydown Loans
included in a Mortgage Pool may be deposited on the date of settlement of the   
sale of the Certificates to the original purchasers thereof (the 'Closing Date')
into either (a) a separate account (the 'Buydown Fund Account') maintained (i)  
with the Trustee or another financial institution approved by the Company or    
Servicing Entity, as applicable, as Master Servicer, (ii) within FDIC insured   
accounts (or other insured accounts acceptable to the rating agency or agencies)
held and monitored by a Servicer or (iii) in a separate non-trust account       
without FDIC or other insurance in an institution having the highest unsecured  
long-term debt rating by the rating agency or agencies (or such other           
institution acceptable to the rating agency or agencies) or (b) held in a       
Custodial Account for P&I or a Custodial Account for Reserves and monitored by a
Servicer. Since Buydown Funds may be funded at either the par values of future  
payment subsidies                                                               

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or funded in an amount less than the par values of future payment subsidies and 
determined by discounting such par values in accordance with interest accruing  
on such values, Buydown Fund Accounts may be non-interest-bearing or may bear   
interest. In no event will the amount held in any Buydown Fund Account exceed   
the level of deposit insurance covering such account. Accordingly, more than one
such account may be established.                                                

SUBSTITUTION OF MORTGAGE LOANS                                                  

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer, the Company or the Servicing      
Entity, as applicable, may substitute an eligible mortgage loan for a defective 
Mortgage Loan (or, if applicable, a Mortgage Loan in its related Mortgage Loan  
Servicing Group) in lieu of repurchasing such defective Mortgage Loan or the    
related Mortgaged Property (a) within three months after the Closing Date for   
the related Series of Certificates, and (b) within two years after such Closing 
Date, if the related Mortgage Loan is a 'defective obligation' within the       
meaning of Section 860G(a)(4)(A)(ii) of the Code. Any mortgage loan, to be      
eligible for substitution, must fit within the general description of the       
Mortgage Loans set forth herein and in the related Prospectus Supplement. With  
respect to Series of Certificates as to which there will be no Master Servicer, 
the Seller or the Servicer, as specified in the related Prospectus Supplement,  
may substitute an eligible mortgage loan for a defective Mortgage Loan in lieu  
of repurchasing such defective Mortgage Loan or the related Mortgaged Property  
in the circumstances and to the extent described in the two preceding sentences.
See 'The Mortgage Pools'.                                                       

REPRESENTATIONS AND WARRANTIES                                                  

Unless otherwise stated in the applicable Prospectus Supplement, in the 
Pooling Agreement for each Series of Certificates as to which the Company will  
act as a Master Servicer, the Company will represent and warrant to the Trust   
with respect to (a) all Mortgage Loans if it is the only Master Servicer and (b)
the Mortgage Loans in its Mortgage Loan Servicing Group if both the Company and 
a Servicing Entity are acting as Master Servicers, among other things, that (i) 
the information set forth in the schedule of Mortgage Loans is true and correct 
in all material respects; (ii) except in the case of Cooperative Loans, a       
lender's title policy (or other satisfactory evidence of title) was issued on   
the date of the origination of each Mortgage Loan and each such policy or other 
evidence of title is valid and remains in full force and effect; (iii) if a     
Primary Insurance Policy, FHA Insurance Policy or VA Guaranty is required with  
respect to such Mortgage Loan, such policy or guaranty is valid and remains in  
full force and effect as of the Closing Date; (iv) immediately upon the transfer
and assignment of the Mortgage Loans to the Trust, the Trust will have good     
title to the Mortgage Loans; (v) as of the Closing Date, the Mortgage Notes are 
subject to no offsets, defenses or counterclaims, except to the extent that the 
buydown agreement for a Buydown Loan forgives certain indebtedness of a         
Mortgagor; (vi) except in the case of Cooperative Loans, as of the Closing Date,
each Mortgage is a valid first lien on an unencumbered estate in fee simple or  
leasehold interest in the Mortgaged Property (subject only to (a) liens for     
current real property taxes and special assessments, (b) covenants, conditions  
and restrictions, rights of way, easements and other matters of public record as
of the date of recording of such Mortgage, such exceptions appearing of record  
being acceptable to mortgage lending institutions generally or specifically     
reflected in the mortgage originator's appraisal, (c) exceptions set forth in   
the title insurance policy covering such Mortgaged Property and (d) other       
matters to which like properties are commonly subject which do not materially   
interfere with the benefits of the security intended to be provided by the      
Mortgage); (vii) as of the Closing Date, each Mortgaged Property is free of     
damage and is in good repair, except for ordinary wear and tear; (viii) as of   
the time each Mortgage Loan was originated, the Mortgage Loan complies with all 
applicable state and federal laws, including usury, equal credit opportunity,   
disclosure and recording laws; (ix) as of the Closing Date, there are no        
delinquent tax or assessment liens against any Mortgaged Property; and          
(x) unless otherwise specified in the related Prospectus Supplement, each       
Mortgage Loan was originated and will be serviced by (a) an institution which is
a member of the Federal Reserve System or the deposits of which are insured by  
the FDIC, (b) an institution which is a member of the Federal Home Loan Bank    
System, (c) an institution which is a FHA-Approved Mortgagee, (d) an institution
which is a Fannie Mae Approved Mortgagee, or (e) an institution which is a      
Freddie Mac Approved Mortgagee. The applicable Prospectus Supplement and Pooling
Agreement may set forth additional representations and                          

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warranties of the Company. In addition, with respect to any Mortgage Loan as to 
which the Company delivers to the Trustee or the custodian an affidavit         
certifying that the original Mortgage Note has been lost or destroyed, if such  
Mortgage Loan subsequently is in default and the enforcement thereof or of the  
related Mortgage is materially adversely affected by the absence of the original
Mortgage Note, the Company will be obligated to repurchase or substitute for    
such Mortgage Loan in the manner described below.                               

If the Mortgage Loans include Cooperative Loans, representations and    
warranties with respect to title insurance or hazard insurance will not be      
given. Generally, a Cooperative itself is responsible for the maintenance of    
hazard insurance for property owned by such Cooperative, and the borrowers      
(tenant-stockholders) of such Cooperative do not maintain hazard insurance on   
their individual dwelling units. Title insurance is not obtained for Cooperative
Loans because such loans are not secured by real property. See 'Certain Legal   
Aspects of the Mortgage Loans -- Cooperative Loans'.                            

   With respect to Series of Certificates as to which the Company will not act
as a Master Servicer, the Seller or the Servicing Entity, as applicable, which  
sold the Mortgage Loans to the Company for conveyance to the Trust will make    
representations and warranties to the Company with respect to such Mortgage     
Loans substantially similar to those indicated in the second preceding          
paragraph, and the Company will assign such representations and warranties to   
the Trust under the Pooling Agreement. The applicable Prospectus Supplement and 
Pooling Agreement may set forth additional representations and warranties of the
Seller, the Servicing Entity and/or the Company.                                

 In the event of the discovery by the Company, the Servicing Entity or the
Servicer of a breach of any representation or warranty which materially and     
adversely affects the interest of the Trust in the related Mortgage Loan, or the
receipt of notice of such a breach from the Trustee, the Company, the Servicing 
Entity or the Seller, as the case may be, will cure the breach, substitute a new
mortgage loan for such Mortgage Loan or repurchase such Mortgage Loan, or any   
Mortgaged Property acquired with respect thereto, on the terms set forth above  
under ' -- Assignment of Mortgage Loans'. The proceeds of any such repurchase   
will be passed through to Certificateholders as liquidation proceeds. This      
substitution or repurchase obligation constitutes the sole remedy available to  
the Certificateholders or the Trust for any such breach.                        

SERVICING                                                                       

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer, pursuant to the Pooling Agreement 
the Company or Servicing Entity, as applicable, as Master Servicer, will be     
responsible for servicing and administering the Mortgage Loans, or the Mortgage 
Loans in its respective Mortgage Loan Servicing Group, as applicable, but will  
be permitted to contract with the Seller/Servicer from whom each Mortgage Loan  
was purchased, or another eligible servicing institution, to perform such       
functions under the supervision of the Master Servicer as more fully described  
below.                                                                          

In the contract pursuant to which each Seller/Servicer will perform its 
servicing duties, which contract will generally be the Selling and Servicing    
Contract, each Seller/Servicer will agree, subject to the general supervision of
the Company or Servicing Entity, as applicable, as Master Servicer, or its      
respective agent, to perform diligently all services and duties customary to the
servicing of mortgage loans. Such Master Servicer or its agent will monitor each
Seller/Servicer's performance and, unless otherwise specified in the applicable 
Prospectus Supplement, such Master Servicer will have the right to remove and   
substitute a replacement Seller/Servicer at any time if it considers such       
removal to be in the best interest of Certificateholders. The duties performed  
by the Seller/Servicers include collection and remittance of principal and      
interest payments, administration of mortgage escrow accounts, collection of    
insurance claims and, if necessary, foreclosure. In the event a Selling and     
Servicing Contract is terminated by the Company or Servicing Entity, as         
applicable, as Master Servicer, for any reason, such Master Servicer may procure
a substitute Seller/Servicer, which may be an affiliate of such Master Servicer.
During the period necessary to effect the execution and implementation of a     
contract with such substitute Seller/Servicer, all duties and responsibilities  
of the Seller/Servicer under the terminated Selling and Servicing Contract will 
be performed by such Master Servicer. In such event, such Master Servicer will  
be entitled to retain the same Servicing Fee as was paid to the Seller/Servicer 
under such terminated Selling and Servicing Contract.                           

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  With respect to Series of Certificates as to which there will be no Master
Servicer, pursuant to the Pooling Agreement the servicing of the Mortgage Loans 
will be performed by the Servicer, and the Company (as Certificate              
Administrator) will calculate amounts distributable to the Certificateholders,  
prepare tax returns on behalf of the Trust and provide certain other            
administrative services specified in the Pooling Agreement. With respect to a   
Series as to which the Company and the Servicing Entity will act as Master      
Servicers, unless otherwise specified in the applicable Prospectus Supplement,  
the Company will also act as the Certificate Administrator. Unless otherwise    
specified in the related Prospectus Supplement, with respect to a Series as to  
which a Servicing Entity is the only Master Servicer, such Servicing Entity     
shall act as the Certificate Administrator. The Servicer will generally perform 
the same services and duties as a Seller/Servicer under a Selling and Servicing 
Agreement, as well as certain services of a Master Servicer described herein.   
The Trustee or its agent will monitor the Servicer's performance and, unless    
otherwise specified in the applicable Prospectus Supplement, the Trustee will   
have the right to remove and substitute a replacement servicer, which may be the
Company or an affiliate of the Company, to assume the servicing obligations of  
the Servicer at any time if it considers such removal to be in the best         
interests of Certificateholders. During the period necessary to effect the      
execution and implementation of a contract with such substitute servicer,       
certain duties and responsibilities of the Servicer under the Pooling Agreement 
will be performed by the Trustee. In such event, the Trustee will be entitled to
retain the same Servicing Fee as was to be paid the Servicer under the Pooling  
Agreement. The obligation of the Trustee or a replacement servicer to perform   
the servicing duties of the Servicer will not, however, require such party to   
cure any defect with respect to any Mortgage Loan, or substitute a new mortgage 
loan for or repurchase a Mortgage Loan as to which there has been a breach of a 
representation or warranty made by the Seller or to cure any breach of a        
servicing covenant made by the former Servicer.                                 

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer, each Seller/Servicer will retain  
as its Servicing Fee a portion of the interest payable on each Mortgage Loan    
serviced by it. The Servicing Fee will be established by the Company or a       
Servicing Entity, as applicable, either as a fixed rate or as a rate calculated 
as the difference between interest at the Mortgage Interest Rate and interest at
the rate required to be passed through to the Company or Servicing Entity, as   
applicable, as Master Servicer (the 'Net Rate'). Unless otherwise set forth in  
the applicable Prospectus Supplement, the Servicing Fee will be no less than    
0.25% per annum for each individual Mortgage Loan serviced. In addition, unless 
otherwise set forth in the Prospectus Supplement, the Seller/Servicer will      
retain late charges, assumption fees and similar charges to the extent collected
from Mortgagors. The Company expects that such fees and charges will be         
negligible in amount. Unless otherwise provided in the applicable Prospectus    
Supplement, each of the Company and Servicing Entity, as applicable, as Master  
Servicer, will retain as its Master Servicing Fee an amount which will be       
calculated as a per annum percentage for each Mortgage Loan plus an amount      
calculated to reimburse the Company or Servicing Entity, as applicable, as      
Master Servicer, for the expenses required to be borne by it, which, unless     
otherwise set forth in the applicable Prospectus Supplement, will include the   
Trustee's fees and premiums on or other expenses relating to any Mortgage Pool  
Insurance Policy and/or other credit enhancements.                              

  With respect to Series of Certificates as to which there will be no Master
Servicer, the Servicer will receive a Servicing Fee, as established in the      
applicable Pooling Agreement, which, unless otherwise indicated in the          
applicable Prospectus Supplement, will be no less than 0.25% per annum for each 
individual Mortgage Loan serviced and with respect to each such Series and each 
Series as to which both the Company and a Servicing Entity are acting as Master 
Servicers, the Certificate Administrator will retain as its Certificate         
Administrator Fee an amount which will be calculated as a per annum percentage  
for each Mortgage Loan plus an amount calculated to reimburse the Certificate   
Administrator for payment by it of the Trustee's fees.                          

RETAINED YIELD                                                                  

    For certain Series, the Company, a Servicing Entity or a Seller may retain a
portion of the interest payable on each Mortgage Loan (the 'Retained Yield').   
The Retained Yield will either be set as a fixed rate or will be calculated by  
subtracting the Master Servicing Fee and the Certificate Interest Rate from the 
Net Rate or, if applicable, by subtracting the Servicing Fee, the Certificate   
Administrator Fee and the                                                       

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Certificate Interest Rate from interest at the Mortgage Interest Rate. Unless   
otherwise specified in the applicable Prospectus Supplement, any such Retained  
Yield and any earnings from reinvestments thereof will not be part of the assets
of the Trust. The Company, the Servicing Entity or the Seller, as the case may  
be, may at its option transfer to a third party all or a portion of the Retained
Yield for a Series of Certificates.                                             

PAYMENTS ON MORTGAGE LOANS; CUSTODIAL ACCOUNTS FOR P&I,                         
INVESTMENT ACCOUNT, CERTIFICATE ACCOUNT AND RESERVE ACCOUNT                     

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer, pursuant to the Servicing Contract
each Seller/Servicer will agree to establish and maintain for the Master        
Servicer (or for the related Master Servicer if both the Company and a Servicing
Entity are acting as Master Servicers for such Series) a special custodial      
account for principal and interest (the 'Custodial Account for P&I'), into which
it will deposit on a daily basis (unless otherwise specified in the applicable  
Prospectus Supplement) the following payments and collections received          
subsequent to the Cut-Off Date (other than payments due on or before the Cut-Off
Date) with respect to the Mortgage Loans serviced by it:                        

(i) All payments on account of principal and interest, including
Principal Prepayments;                                                  

    (ii) All net proceeds received in connection with the liquidation of
   defaulted Mortgage Loans, by foreclosure or otherwise (hereinafter referred
  to as 'Liquidation Proceeds'), or under any applicable credit enhancements
    or title, hazard or other insurance policy covering any Mortgage Loan, other
than proceeds to be applied to the restoration or repair of the related 
Mortgaged Property (hereinafter referred to as 'Insurance Proceeds');   

       (iii) Any Advances of such Seller/Servicer's funds (such Advances to be
deposited prior to the Withdrawal Date, as defined below); and          

       (iv) All proceeds of any Mortgage Loans or property acquired in respect
thereof repurchased as required for defects in documentation, breach of 
representations or warranties, or otherwise.                            

   Each Seller/Servicer has the option of either (i) depositing gross interest
collections in the Custodial Account for P&I, subject to withdrawal of its      
related Servicing Fees, or (ii) deducting its Servicing Fees from gross interest
collections prior to deposit in such account.                                   

On the Withdrawal Date or, with the Master Servicer's approval (or the  
related Master Servicer if both the Company and a Servicing Entity are acting as
Master Servicers), on a daily basis, each Seller/Servicer may withdraw the      
following amounts from its Custodial Account for P&I:                           

     (i) Amounts received on particular Mortgage Loans as late payments of
  principal or interest and respecting which the Seller/Servicer has made an
unreimbursed Advance;                                                   

     (ii) Amounts to reimburse the Seller/Servicer for Advances the Master
    Servicer (or the related Master Servicer if both the Company and a Servicing
Entity are acting as Master Servicers) has determined to be otherwise   
nonrecoverable; and                                                     

(iii) Amounts in respect of Servicing Fees previously deposited.

 The Company and/or the Servicing Entity, as applicable, will require that
deposits in each Custodial Account for P&I be held (a) in a trust account in the
corporate trust department of the Trustee or another financial institution      
approved by the Company or Servicing Entity, as applicable, as Master Servicer, 
such that the rights of the Company or Servicing Entity, as applicable, as      
Master Servicer, the Trust and the Certificateholders will be fully protected   
against the claims of any creditors of the Servicer and of any creditors or     
depositors of the institution in which such account is maintained, (b) in FDIC  
insured accounts (or other accounts with comparable insurance coverage          
acceptable to the rating agency or agencies) created maintained and monitored by
a Servicer or (c) in a separate non-trust account without FDIC or other         
insurance in an institution having an unsecured long-term debt rating of at     
least one of the two highest unsecured long-term debt ratings of the rating     
agency or agencies (or such other institution acceptable to the rating agency or
agencies). If a Custodial Account for P&I is insured by the FDIC and at any time
the amount in such account exceeds the limits of insurance on such account, the 

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Seller/Servicer shall be required to withdraw such excess from such account and 
remit it to the Company or Servicing Entity, as applicable, for deposit in the  
Investment Account described below.                                             

 With respect to Series of Certificates as to which the Company and/or the
Servicing Entity, as applicable, will act as Master Servicer and unless         
otherwise specified in the related Prospectus Supplement, not later than the    
20th day of each month (or the preceding business day if such 20th day is not a 
business day) (the 'Withdrawal Date'), the Company or Servicing Entity, as      
applicable, will withdraw or direct the withdrawal from any funds in the        
Custodial Account for P&I maintained by each related Seller/Servicer an amount  
representing:                                                                   

    (i) Scheduled installments of principal and interest on the Mortgage
Loans received or advanced by such Seller/Servicer which were due on the
first day of the current month, net of Servicing Fees due the           
    Seller/Servicer and less any amounts to be withdrawn later by the Company or
  Servicing Entity, as applicable, from any applicable Buydown Fund Account;

(ii) Proceeds of liquidations of Mortgage Loans received by the 
  Seller/Servicer in the immediately preceding calendar month, with interest
  to the date of liquidation, net of Servicing Fees due such Seller/Servicer
and less any amounts to be withdrawn later by the Company or Servicing  
Entity, as applicable, from any applicable Buydown Fund Account;        

       (iii) Principal due to Payoffs received during the period from the 15th
of the immediately preceding calendar month through the 14th of such    
 calendar month; in each case with interest at the applicable Pass-Through
   Rate attributable to interest paid by the Mortgagor through the date of the
   Payoff (provided, however, that in the case of Payoffs received between the
    first day and the 14th day of any month, interest accrued from the first day
of such month to the date of such Payoff will not be paid to the        
  Certificateholders), less any amounts to be withdrawn later by the Company
or Servicing Entity, as applicable, from any applicable Buydown Fund    
Account; and                                                            

   (iv) Curtailments received by such Seller/Servicer on such Mortgage
Loans in the immediately preceding calendar month.                      

    All amounts withdrawn from the Custodial Accounts for P&I, together with any
Insurance Proceeds or Liquidation Proceeds (including any amounts paid in       
respect of repurchase obligations on defective Mortgage Loans or otherwise) not 
otherwise applied by Seller/Servicers and amounts withdrawn from any Buydown    
Fund Account, if applicable, shall be immediately deposited into the Investment 
Account (or if both the Company and a Servicing Entity are acting as Master     
Servicers, the related Investment Account).                                     

   Under the Pooling Agreement for each Series of Certificates as to which the
Company will act as Master Servicer, the Master Servicer or the related         
Seller/Servicer is permitted to make the following withdrawals from the Buydown 
Fund Account or Custodial Account for P&I, as applicable:                       

      (i) To deposit in the Investment Account the amount necessary in order
to supplement payments received on Buydown Loans;                       

(ii) In the event of a Payoff of any Buydown Loan, to apply the 
    remaining related Buydown Funds to reduce the required amount of such Payoff
   (or, if the Mortgagor has made a Payoff equal in amount to the total unpaid
principal balance, to refund such remaining Buydown Funds to the person 
entitled to receive such Buydown Funds);                                

        (iii) In the event of foreclosure or liquidation of any Buydown Loan, to
  deposit the remaining related Buydown Funds in the Investment Account; and

   (iv) To clear and terminate the portion of any account representing
Buydown Funds.                                                          

Unless otherwise specified in the applicable Prospectus Supplement, the 
Company or Servicing Entity, as applicable, as Master Servicer, may invest funds
withdrawn from the Custodial Accounts for P&I each month and remitted to the    
related Master Servicer, as well as any Insurance Proceeds, Liquidation Proceeds
and Buydown Funds, for its own account and at its own risk, for the period from 
the Withdrawal Date to the next Distribution Date, or for such longer or shorter
period as may be specified in the applicable Prospectus Supplement (in each     
case, the 'Investment Period'). Notwithstanding the foregoing, in the event that
both the Company and a Servicing Entity are acting as Master Servicers with     
respect to any Series, each of the Company and such Servicing Entity may only   
invest funds described in the preceding sentence to the extent that such funds  
relate to Mortgage Loans in its respective Mortgage                             

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Loan Servicing Group. Investment of such funds shall be made through an account 
in the name of the Company or Servicing Entity, as applicable, as Master        
Servicer, and the Trust (an 'Investment Account') (or, if both the Company and a
Servicing Entity are acting as Master Servicers, to the extent that such funds  
relate to Mortgage Loans in its respective Mortgage Loan Servicing Group), which
shall be maintained in the trust department of a bank acceptable to any         
applicable rating agency or agencies for the Series of Certificates. The        
Investment Account may be a commingled account with other similar accounts      
maintained by the Company or Servicing Entity, as applicable, as Master         
Servicer, and invested for its own account; provided, that the maintenance of   
such a commingled account has been approved by any applicable rating agency or  
agencies for the Series of Certificates. Unless otherwise specified in the      
applicable Prospectus Supplement, the investment of funds in the Investment     
Account shall be limited to the investments described below.                    

  On the last day of the Investment Period, the Company or Servicing Entity,
as applicable, as Master Servicer, will withdraw from the Investment Account    
(or, if both the Company and a Servicing Entity are acting as Master Servicers, 
the related Investment Account) all funds due to be distributed to              
Certificateholders, and shall deposit such funds, together with any Advances    
required to be made by it, in the Certificate Account described below.          

Unless otherwise specified in the applicable Prospectus Supplement, the 
investment of funds in an Investment Account shall be limited to one or more of 
the following investments ('Eligible Investments') which shall in no event      
mature later than the next Distribution Date:                                   

      (i) Obligations of, or guaranteed as to principal and interest by, the
United States or any agency or instrumentality thereof, when such       
 obligations are backed by the full faith and credit of the United States;

 (ii) Repurchase agreements on obligations of, or guaranteed as to
principal and interest by, the United States or any agency or           
   instrumentality thereof, when such obligations are backed by the full faith
   and credit of the United States; provided that the unsecured obligations of
  the party agreeing to repurchase such obligations are at the time assigned
   such ratings as may be required by the applicable rating agency or agencies
for the Series of Certificates at the date of acquisition thereof;      

        (iii) Federal funds, certificates of deposit, time deposits and bankers'
   acceptances of any bank or trust company incorporated under the laws of the
 United States or any state thereof; provided that the debt obligations of
   such bank or trust company (or, in the case of the principal bank in a bank
  holding company system, debt obligations of the bank holding company) have
been assigned such ratings as may be required by the applicable rating  
agency or rating agencies for the Series of Certificates at the date of 
acquisition thereof;                                                    

        (iv) Obligations of, or guaranteed by, any state of the United States or
the District of Columbia receiving the highest long-term debt ratings   
available for such securities by the applicable rating agency or rating 
agencies for the Series of Certificates;                                

      (v) Commercial paper of any corporation incorporated under the laws of
   the United States or any state thereof which on the date of acquisition has
been assigned such ratings as may be required by the applicable rating  
agency or rating agencies for the Series of Certificates; or            

       (vi) Securities (other than stripped bonds or stripped coupons) bearing
interest or sold at a discount that are issued by any corporation       
 incorporated under the laws of the United States or any state thereof and
   rated by each applicable rating agency or rating agencies for the Series of
  Certificates in its highest long-term unsecured rating category; provided,
however, that securities issued by any such corporation will not be     
investments to the extent that investment therein would cause the       
  outstanding principal amount of securities issued by such corporation that
  are then held as part of the Investment Account or the Certificate Account
   to exceed 20% of the aggregate principal amount of all Eligible Investments
then held in the Investment Account and the Certificate Account;        

       (vii) Units of taxable money market funds or mutual funds (which may be
  12b-1 funds, as contemplated under the rules promulgated by the Commission
 under the Investment Company Act of 1940), which funds have been rated by
each applicable rating agency or rating agencies for the Series of      
    Certificates in its highest rating category or which have been designated in
writing by each such rating agency or rating agencies as Eligible       
Investments with respect to this definition; or                         

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  (viii) such other investments the investment in which will not, as
   evidenced by a letter from each applicable rating agency or rating agencies
  for the Series of Certificates, result in the downgrading or withdrawal of
   the rating or ratings assigned to the Certificates by such rating agency or
rating agencies.                                                        

Not later than the Distribution Date for a Series of Certificates as to 
which the Company and/or a Servicing Entity will act as Master Servicer, the    
Company or Servicing Entity, as applicable, will withdraw from the Investment   
Account (or, if both the Company and a Servicing Entity are acting as Master    
Servicers, the related Investment Account) all amounts required to be           
distributed on such Distribution Date and deposit such amounts into a separate  
non-interest-bearing trust account (the 'Certificate Account') in the corporate 
trust department of the Trustee or another depository institution acceptable to 
the applicable rating agency or rating agencies.                                

   Under the Pooling Agreement for each Series of Certificates as to which the
Company and/or a Servicing Entity will act as Master Servicer, the Company or   
Servicing Entity, as applicable, will be authorized to make the following       
withdrawals from the Certificate Account (provided, however, that if both the   
Company and a Servicing Entity are acting as Master Servicers, each of the      
Company's and Servicing Entity's right to any such withdrawals will be limited  
to proceeds received in respect of Mortgage Loans in its respective Mortgage    
Loan Servicing Group):                                                          

   (i) To reimburse the Company or Servicing Entity, as applicable, as
 Master Servicer, or the applicable Servicer for Advances made pursuant to
   the Pooling Agreement or a Selling and Servicing Contract, the Company's or
 Servicing Entity's right to reimburse itself or such Servicer pursuant to
   this paragraph (i) being limited to amounts received on particular Mortgage
Loans (including, for this purpose, Insurance Proceeds and Liquidation  
Proceeds) which represent late recoveries of principal and/or interest  
respecting which any such Advance was made;                             

    (ii) To reimburse the Company or Servicing Entity, as applicable, as
  Master Servicer, or the applicable Servicer for amounts expended by or for
the account of the Company or Servicing Entity, as applicable, as Master
Servicer, pursuant to the Pooling Agreement or amounts expended by such 
   Servicer pursuant to the Selling and Servicing Contracts in connection with
    the restoration of property damaged by an Uninsured Cause (as defined in the
    Pooling Agreement) or in connection with the liquidation of a Mortgage Loan;

  (iii) To pay to the Company or Servicing Entity, as applicable, as
Master Servicer, the Master Servicing Fee, net of Compensating Interest 
    reduced by Payoff Earnings and Payoff Interest (each as defined herein or in
the Pooling Agreement), as to which no prior withdrawals from funds     
deposited by the Master Servicer have been made;                        

    (iv) To reimburse the Company or Servicing Entity, as applicable, as
  Master Servicer, or the applicable Servicer for advances which the Company
or Servicing Entity, as applicable, has determined to be Nonrecoverable 
Advances;                                                               

       (v) To pay to the Company or Servicing Entity, as applicable, as Master
Servicer, reinvestment earnings deposited or earned in the Certificate  
Account (net of reinvestment losses) to which the Company or Servicing  
    Entity, as applicable, is entitled and to reimburse the Company or Servicing
Entity, as applicable, for expenses incurred by and reimbursable to the 
Company or Servicing Entity, as applicable, pursuant to the Pooling     
Agreement;                                                              

      (vi) To deposit amounts in the Investment Account representing amounts
    in the Certificate Account not required to be on deposit therein at the time
of such withdrawal; and,                                                

after making or providing for the above withdrawals,                    

        (vii) To clear and terminate the Certificate Account upon liquidation of
all Mortgage Loans or other termination of the Trust.                   

   Each of the Company and Servicing Entity, as applicable, may also establish
with the Trustee for a Series of Certificates as to which it is acting as a     
Master Servicer a Reserve Account if required to assure timely distributions of 
principal and interest, as a condition to obtaining a specified rating for such 
Certificates or to provide for the expenses of the Trust. Any such Reserve      
Account so established will be described in the applicable Prospectus           
Supplement.                                                                     

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  With respect to Series of Certificates as to which there will be no Master
Servicer, unless otherwise specified in the applicable Prospectus Supplement,   
the Custodial Account for P&I, the Buydown Fund Account and the Reserve Account 
will be established by the Servicer, and the required and permitted deposits    
into and withdrawals from such accounts set forth above will be made by the     
Servicer. The Servicer shall deposit any required Advances in the Custodial     
Account for P&I on the Withdrawal Date. The withdrawal of funds and their       
deposit into the Investment Account on the Withdrawal Date, as described above, 
will also be effected by the Servicer. The Investment Account described above   
will be established by the Certificate Administrator and the Trustee, and       
investments of amounts therein in Eligible Investments will be directed by the  
Certificate Administrator for its own account and at its own risk. The          
Certificate Administrator will make the required withdrawal from the Investment 
Account on the last day of the Investment Period for deposit in the Certificate 
Account, as described above. Authorized withdrawals from the Certificate Account
for the purposes described above will be made by the Certificate Administrator. 
Other than as set forth in this paragraph, unless the context otherwise         
requires, references above to 'Master Servicer' or 'Seller/Servicer', and to    
'Master Servicing Fee' shall refer instead to 'Servicer' and 'Servicing Fee',   
respectively.                                                                   

PRE-FUNDING ACCOUNT                                                             

  If stated in the accompanying Prospectus Supplement, the Pooling Agreement
or other agreement may provide for the transfer of additional Mortgage Loans    
(the 'Subsequent Loans') to the related Trust after the closing date for the    
related Certificates. An account (a 'Pre-Funding Account') will be established  
for the purpose of funding the transfer of Subsequent Loans into the related    
Trust. Any Subsequent Loans will be required to conform to the requirements     
described in the related Pooling Agreement or other agreement providing for such
transfer. If a Pre-Funding Account is established, an amount will be deposited  
in such account to be released as Subsequent Loans are transferred. All amounts 
in the Pre-Funding Account will be required to be invested in Eligible          
Investments and the amount held in the Pre-Funding Account shall at no time     
exceed 25% of the aggregate outstanding principal balance of the Certificates.  
Unless otherwise specified in the accompanying Prospectus Supplement, the       
related Pooling Agreement or other agreement providing for the transfer of      
Subsequent Loans will provide that all transfers must be made within 90 days,   
and that amounts set aside to fund the transfers, whether in a Pre-Funding      
Account or otherwise, and not so applied within the required period of time will
be deemed to be Principal Prepayments and applied in the manner described in the
Prospectus Supplement.                                                          

DISTRIBUTIONS ON CERTIFICATES                                                   

    For each Series, on each Distribution Date commencing in the month following
the month in which the Cut-Off Date occurs (or such other time as may be set    
forth in the applicable Prospectus Supplement), the Trustee, the Master Servicer
(if there will be only one Master Servicer) or the Certificate Administrator, as
applicable, acting on behalf of the Trustee or the Paying Agent will withdraw   
from the Certificate Account and distribute to Certificateholders of record on  
the applicable Record Date, and to holders of residual interests, if any, who   
are entitled to receive such distributions pursuant to the terms of the         
applicable Pooling Agreement, to the extent of their entitlement thereto, an    
amount in the aggregate equal to the sum of:                                    

        (i) All scheduled payments of principal and interest at the Pass-Through
    Rate either collected from the Mortgagors on the Mortgage Loans prior to the
   related Determination Date (as defined below) or advanced by the Company or
Servicing Entity, as applicable, the Servicer or the Seller/Servicers;  

     (ii) Scheduled amounts of Buydown Funds respecting Buydown Loans (not
 withdrawn and remitted by the Servicer or the related Seller/Servicer, as
applicable);                                                            

        (iii) All Curtailments received on the Mortgage Loans in the month prior
to the month in which the Distribution Date occurs (the 'Distribution   
Period');                                                               

       (iv) All Insurance Proceeds or Liquidation Proceeds received during the
  Distribution Period, together with interest at the applicable Pass-Through
    Rate to the extent described herein under 'Yield Considerations -- Effective
Interest Rate'; and                                                     

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   (v) All Payoffs received during the period from the 15th day of the
  immediately preceding calendar month through the 14th day of such calendar
 month; in each case together with interest at the applicable Pass-Through
Rate to the extent described under 'Yield Considerations -- Effective   
Interest Rate' herein;                                                  

less the sum of:                                                        

     (a) Previously unreimbursed Advances made by the Company or Servicing
Entity, as applicable, as Master Servicer, the Seller/Servicers or the  
 Servicer on Mortgage Loans which are considered by the Master Servicer or
the Servicer, as the case may be, as of the Distribution Date to be     
nonrecoverable;                                                         

      (b) Amounts expended by the Seller/Servicers, the Company or Servicing
    Entity, as applicable, as Master Servicer or the Servicer in connection with
 the preservation or restoration of property securing Mortgage Loans which
have been liquidated and related liquidation expenses; and              

   (c) Amounts representing other expenses of the Master Servicer, the
Seller/Servicers or the Servicer, reimbursable pursuant to the Pooling  
Agreement;                                                              

provided, however, that in the event that both the Company and a Servicing      
Entity are acting as Master Servicers for any Series, any amounts retained on   
behalf of any of the Company, such Servicing Entity or a related Seller/Servicer
pursuant to clauses (a), (b) and (c) above shall be limited to amounts received 
in respect of any Mortgage Loans in its related Mortgage Loan Servicing Group.  

  In addition, if the Master Servicer with respect to Series of Certificates
as to which the Company and/or a Servicing Entity will act as Master Servicer,  
or the Servicer with respect to Series of Certificates as to which there will be
no Master Servicer, is obligated to do so under the applicable Pooling          
Agreement, such Master Servicer or the Servicer, as the case may be, shall      
include with any such distribution an Advance equal to principal payments and   
interest payments (adjusted to the applicable Pass-Through Rate or Rates) due on
the first day of the month in which the Distribution Date occurs and not        
received as of the close of business on the Withdrawal Date, subject to such    
Master Servicer's or Servicer's determination that such payments are recoverable
from future payments or collections on the Mortgage Loans, any subordination    
feature or Insurance Proceeds or Liquidation Proceeds. See ' -- Advances' below.

  The method of allocating the amount withdrawn from the Certificate Account
on each Distribution Date to principal and interest (or, where applicable, to   
principal only or interest only) on a particular Series of Certificates will be 
described in the applicable Prospectus Supplement. Distributions of interest on 
each Class of Certificates will be made prior to distributions of principal     
thereon. Each Class of Certificates may have a different Certificate Interest   
Rate, and each Certificate Interest Rate may be fixed, variable or adjustable.  
The applicable Prospectus Supplement will specify the Certificate Interest Rate 
for each Class, or in the case of a variable or adjustable Certificate Interest 
Rate, the initial Certificate Interest Rate and the method for determining the  
Certificate Interest Rate.                                                      

On each Distribution Date for a Series of Certificates, the Trustee, the
Master Servicer (if there will be only one Master Servicer) or the Certificate  
Administrator, as applicable, on behalf of the Trustee or the Paying Agent, as  
the case may be, will distribute to each holder of record on the Record Date, an
amount equal to the Percentage Interest (as defined below) represented by the   
Certificate held by such holder multiplied by the sum of the Class Principal    
Distribution Amount (as defined below) for such Class and, if such Class is     
entitled to payments of interest on such Distribution Date, one month's interest
at the applicable Certificate Interest Rate on the principal balance or notional
principal balance of such Class specified in the applicable Prospectus          
Supplement, less (unless otherwise specified in the related Prospectus          
Supplement) such Class's pro rata share of the sum of (i) the shortfalls in     
collections of interest on Payoffs with respect to which distribution is to be  
made on such Distribution Date, if any, (ii) the amount of any deferred interest
added to the principal balance of the Mortgage Loans and/or the outstanding     
balance of the Certificates on the related Due Date, (iii) one month's interest 
at the applicable Pass-Through Rate on the amount of any Curtailments received  
on the Mortgage Loans in the month preceding the month of the distribution and  
(iv) any other interest shortfalls (including, without limitation, shortfalls   
arising out of application of the Servicemembers Relief Act or similar          
legislation or regulations as in effect from time to time) allocable to         
Certificateholders which are not covered by advances or applicable              

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credit enhancements, in each case in such amount as is allocated to such Class  
on the basis set forth in the related Prospectus Supplement. The 'Percentage    
Interest' represented by a Certificate of a particular Class will be equal to   
the percentage obtained by dividing the initial principal balance or notional   
amount of such Certificate by the aggregate initial amount or notional amount of
all the Certificates of such Class. The 'Class Principal Distribution Amount'   
for a Class of Certificates for any Distribution Date will be the portion, if   
any, of the Principal Distribution Amount (as defined in the related Prospectus 
Supplement) allocable to such Class for such Distribution Date, as described in 
the related Prospectus Supplement.                                              

  In the case of a Series of Certificates which includes two or more Classes
of Certificates, the timing, sequential order, priority of payment or amount of 
distributions in respect of principal, and any schedule or formula or other     
provisions applicable to the determination thereof with respect to each such    
Class shall be as provided in the related Prospectus Supplement. Distributions  
in respect of principal of any Class of Certificates will be made on a pro rata 
basis among all of the Certificates of such Class.                              

 With respect to Series of Certificates as to which there will be only one
Master Servicer and except as otherwise provided in the applicable Pooling      
Agreement, not later than the tenth day preceding each Distribution Date (the   
'Determination Date'), such Master Servicer will furnish to the Trustee (and to 
any Certificateholder upon request) a statement setting forth the aggregate     
amount to be distributed on such Distribution Date to each Class of             
Certificates, on account of principal and/or interest, stated separately. With  
respect to Series of Certificates as to which there will be no Master Servicer, 
or as to which both the Company and a Servicing Entity will act as Master       
Servicers, the Certificate Administrator will provide the statements described  
in the preceding sentence.                                                      

REPORTS TO CERTIFICATEHOLDERS                                                   

For each Series of Certificates, with each distribution to              
Certificateholders from the Certificate Account, the Trustee, or the Master     
Servicer (if there will be only one Master Servicer) or Certificate             
Administrator, as applicable, on behalf of the Trustee, will forward to each    
Certificateholder or publish electronically a statement or statements with      
respect to the assets of the related Trust setting forth the information        
specifically described in the related Pooling Agreement, which generally will   
include the following with respect to such Series of Certificates:              

 (i) the beginning principal balance or notional principal balance
representing the ending balance from the prior statement;               

(ii) the amount, if any, of such distribution principal;        

       (iii) the amount, if any, of such distribution allocable to interest on
the Mortgage Loans accrued at the applicable Pass-Through Rate on the   
    beginning principal balance or notional principal balance, and, with respect
to a Series of Certificates where one or more Classes of such Series are
subordinated in right of payment to one or more other Classes of such   
  Series, the amount, if any, of any shortfall in the amount of interest and
principal distributed;                                                  

(iv) the total amount distributed;                              

        (v) the ending principal balance or notional principal balance after the
application in (ii) above; and                                          

(vi) the then applicable Pass-Through Rate or weighted average  
Pass-Through Rate, calculated as of the close of business on the related
Determination Date.                                                     

 Upon request, a Certificateholder may receive a monthly report which sets
forth (i) the amount of the distribution for such month allocable to Principal  
Prepayments, miscellaneous post-liquidation collections and Conversion Fees,    
(ii) Mortgage Loan delinquencies, indicating the number and aggregate principal 
amount of Mortgage Loans delinquent one, two and three months, as well as the   
book value of any Mortgaged Property acquired through foreclosure, deed in lieu 
of foreclosure or other exercise of rights respecting the Trust's security      
interest in the Mortgage Loans, (iii) the amount of remaining coverage under any
applicable credit enhancements, stated separately, as of the close of business  
on the applicable Determination Date and (iv) the sum of the Master Servicing   
Fee and the aggregate Servicing Fees for the month.                             

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 In addition, by the date required by applicable tax law of each year, the
Master Servicer with respect to Series of Certificates as to which there will be
only one Master Servicer, or the Certificate Administrator with respect to      
Series of Certificates as to which there will be no Master Servicer or as to    
which both the Company and a Servicing Entity will act as Master Servicers, will
furnish a report to each Certificateholder of record at any time during the     
preceding calendar year as to the aggregate of amounts reported pursuant to (ii)
in the second preceding paragraph above, plus information with respect to the   
amount of servicing compensation for the related Mortgage Pool, the value of any
property acquired by the Trust through abandonment or foreclosure, deferred     
interest added to the principal balance or the notional principal balance of    
each Class of Certificates, as applicable, and such other customary information 
as the Master Servicer or Certificate Administrator, as applicable, determines  
to be necessary to enable Certificateholders to prepare their tax returns for   
such calendar year or, in the event such person was a Certificateholder of      
record during a portion of such calendar year, for the applicable portion of    
such a year.                                                                    

ADVANCES                                                                        

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer and unless otherwise stated in the 
applicable Prospectus Supplement, the Company or Servicing Entity, as           
applicable, will be obligated under the Pooling Agreement to make Advances (to  
the extent not previously advanced by the Seller/Servicers as described below). 
In the event that both the Company and a Servicing Entity are acting as Master  
Servicers for any Series, unless otherwise specified in the applicable          
Prospectus Supplement, each of the Company's and such Servicing Entity's        
obligation to make Advances shall be limited to Mortgage Loans in its respective
Mortgage Loans Servicing Group. Such Advances shall be in amounts sufficient to 
cover any deficiency between the funds scheduled to be received on the Mortgage 
Loans during the Distribution Period, and amounts withdrawn from the Custodial  
Accounts for P&I on each Withdrawal Date during the Distribution Period and from
any Buydown Fund Account; provided, however, that the Company or Servicing      
Entity, as applicable, will be obligated to make such Advances only to the      
extent any such Advance, in the judgment of the Company or Servicing Entity, as 
applicable, made on the Determination Date, will be reimbursable from any       
applicable credit enhancements, from Mortgagor payments or from Liquidation     
Proceeds or Insurance Proceeds of the related Mortgage Loans. In connection with
certain credit enhancements, the Company or Servicing Entity, as applicable, may
make other advances, such as to pay insurance premiums, real estate property    
taxes, protection and preservation taxes, sales expenses and foreclosure costs  
including court costs and reasonable attorneys' fees in connection with a       
Mortgage Pool Insurance Policy, which shall also constitute 'Advances'. If an   
Advance made by a Master Servicer later proves unrecoverable, such Master       
Servicer will be reimbursed from funds in the Certificate Account.              
Notwithstanding the foregoing, if both the Company and a Servicing Entity are   
acting as Master Servicers for any Series, such right of reimbursement shall be 
limited to amounts received in respect of Mortgage Loans in its respective      
Mortgage Loan Servicing Group.                                                  

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer and unless otherwise stated in the 
applicable Prospectus Supplement, each Seller/Servicer will be obligated to     
advance on the Withdrawal Date its own funds or funds from the Custodial Account
for P&I maintained by it equal to the amount of any deficiency between the      
amount in such Custodial Account for P&I on the Withdrawal Date and the amount  
due to be remitted to the Company or Servicing Entity, as applicable, on such   
date. Each Seller/Servicer will advance only funds which the Master Servicer    
anticipates will be ultimately reimbursable from the sources discussed above. To
the extent the Seller/Servicers make such Advances, the Company or Servicing    
Entity, as applicable, will be relieved of its obligation, if any, to make      
Advances with respect to the Mortgage Loans respecting which such amounts were  
advanced. If an Advance made by any Seller/Servicer later proves to be          
unrecoverable, the Company or Servicing Entity, as applicable, will cause such  
Seller/Servicer to be reimbursed from funds in the Certificate Account.         
Notwithstanding the foregoing, if both the Company and a Servicing Entity are   
acting as Master Servicers, such right of reimbursement shall be limited to     
amounts received in respect of Mortgage Loans in its respective Mortgage Loan   
Servicing Group.                                                                

  With respect to Series of Certificates as to which there will be no Master
Servicer and unless otherwise stated in the applicable Prospectus Supplement,   
the Servicer will be obligated under the Pooling                                

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Agreement to advance on the Withdrawal Date its own funds or funds from the     
Custodial Account for P&I equal to the amount of any deficiency between the     
amount in such Custodial Account for P&I on the Withdrawal Date and the amount  
due to be remitted to the Certificate Administrator on such date. The Servicer  
will be obligated to make such Advances only to the extent any such Advance, in 
the judgment of the Servicer made on the related Determination Date, will be    
reimbursable from any applicable credit enhancements, from Mortgagor payments or
from Liquidation Proceeds or Insurance Proceeds of the related Mortgage Loans.  
In connection with certain credit enhancements, the Servicer may make other     
advances, such as to pay insurance premiums, real estate property taxes,        
protection and preservation taxes, sales expenses and foreclosure costs         
including court costs and reasonable attorneys' fees in connection with a       
Mortgage Pool Insurance Policy, which shall also constitute 'Advances'. If an   
Advance made by the Servicer later proves to be unrecoverable, the Servicer will
be reimbursed from funds in the Certificate Account.                            

COLLECTION AND OTHER SERVICING PROCEDURES                                       

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer, under the Selling and Servicing   
Contract each Seller/Servicer agrees to make reasonable efforts to collect all  
payments called for under the Mortgage Notes and will, consistent with the      
Selling and Servicing Contract, the Pooling Agreement for any Series and any    
applicable credit enhancements, follow such collection procedures as it follows 
or would follow with respect to mortgage loans held for its own account which   
are comparable to the Mortgage Loans. With respect to Series of Certificates as 
to which there will be no Master Servicer and the servicing of the Mortgage     
Loans will be performed by the Servicer, the Pooling Agreement will require the 
Servicer to make the same efforts to collect payments on the Mortgage Notes and 
follow the same collection procedures as would be required of the Servicer if it
were a Seller/Servicer under a Selling and Servicing Contract. Consistent with  
the above, each Seller/Servicer with respect to Series of Certificates as to    
which the Company and/or a Servicing Entity will act as Master Servicer, or the 
Servicer with respect to Series of Certificates as to which there will be no    
Master Servicer, may, in its discretion, (i) waive any prepayment charge,       
assumption fee, late payment charge or any other charge in connection with a    
Principal Prepayment on a Mortgage Loan and (ii) only upon receiving            
authorization from the insurer on any applicable Mortgage Pool Insurance Policy 
or Primary Insurance Policy, and with respect to each Seller/Servicer, from the 
Master Servicer, arrange with a Mortgagor a schedule for the liquidation of     
delinquencies running for no more than 180 days after the first delinquent due  
date for payment on any Mortgage Note. Such authorization shall be given by the 
Company or Servicing Entity, as applicable, as Master Servicer, or the Servicer 
only upon determining that the coverage of such Mortgage Loan by any applicable 
credit enhancement will not be affected. In the event of any such arrangement,  
the Company's or Servicing Entity's, as applicable, obligation to make Advances 
on the related Mortgage Loan, if any, shall continue during the scheduled period
to the extent such Advances are not made by the Seller/Servicers.               

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer, the Selling and Servicing Contract
with each Seller/Servicer requires that such Seller/Servicer enforce            
'due-on-sale' clauses, where applicable, with respect to the Mortgage Loans on  
the same basis as with loans in its own portfolio, provided that such clause is 
not to be enforced if it is unenforceable under applicable law or the terms of  
the related Mortgage Note or if the coverage of any related credit enhancement  
would be adversely affected by such enforcement. Subject to the above, if a     
Mortgaged Property has been or is about to be conveyed by the Mortgagor, the    
Seller/Servicer or the Company or Servicing Entity, as applicable, will be      
authorized to take or enter into an assumption agreement, pursuant to which the 
Mortgagor remains liable under the Mortgage Note, from or with the person to    
whom such Mortgaged Property has been or is about to be conveyed. Any fees      
collected by a Seller/Servicer for entering into an assumption agreement will be
retained by it as additional servicing compensation. With respect to Series of  
Certificates as to which there will be no Master Servicer and the servicing of  
the Mortgage Loans will be performed by the Servicer, the Pooling Agreement will
require the Servicer to enforce any 'due-on-sale' clause in the instances and to
the extent described in the first sentence of this paragraph, and the Servicer  
will be authorized to take or enter into an assumption agreement and retain any 
fees collected for entering into an assumption agreement as additional servicing

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compensation to the same extent as a Seller/Servicer will be so authorized under
a Selling and Servicing Contract.                                               

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer, the Company or Servicing Entity,  
as applicable, may, or upon receiving authorization from the Company or         
Servicing Entity, as applicable, as Master Servicer, a Seller/Servicer may, in  
connection with any such conveyance and only upon assurance that the related    
Mortgage Loan will continue to be covered by any applicable credit enhancement, 
release the original Mortgagor from liability upon the Mortgage Note and        
substitute the new Mortgagor as liable thereon. If required by law or the terms 
of the related Mortgage Note, the Company or Servicing Entity, as applicable,   
may allow such release and substitution without the consent of the provider of  
any applicable credit enhancement. In connection with any such assumption or    
substitution, the Mortgage Interest Rate borne by the related Mortgage Note may 
not be changed. With respect to Series of Certificates as to which there will be
no Master Servicer and the servicing of the Mortgage Loans will be performed by 
the Servicer, the Servicer may in connection with any such conveyance release   
the original Mortgager from liability upon the Mortgage Note and substitute a   
new Mortgagor as liable thereon in the instances and to the extent described    
above in this paragraph with respect to the Company or Servicing Entity, as     
applicable, as Master Servicer.                                                 

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer, under each Selling and Servicing  
Contract the Seller/Servicer is required to establish and maintain a Custodial  
Account for Reserves into which Mortgagors deposit amounts sufficient to pay    
taxes, assessments, hazard insurance premiums or comparable items to the extent 
it is consistent with such Seller/Servicer's normal practices to collect        
payments from Mortgagors to cover tax and insurance expenses. Withdrawals from  
the Custodial Account for Reserves maintained for Mortgagors may be made to     
effect timely payment of taxes, assessments and hazard insurance premiums or    
comparable items, to reimburse the Seller/Servicer out of related assessments   
for maintaining hazard insurance, to refund to Mortgagors amounts determined to 
be overages, to pay interest to Mortgagors on balances in the Custodial Account 
for Reserves, if required, to repair or otherwise protect the Mortgaged Property
and to clear and terminate the Custodial Account for Reserves. Each             
Seller/Servicer is solely responsible for administration of the Custodial       
Account for Reserves and is expected to make Advances to such account when a    
deficiency exists therein. With respect to Series of Certificates as to which   
there will be no Master Servicer and the servicing of the Mortgage Loans will be
performed by the Servicer, the Servicer will be required to establish and       
maintain a Custodial Account for Reserves and to make Advances to such account, 
and will be authorized to make withdrawals from the Custodial Account for       
Reserves, in the instances and to the extent a Seller/Servicer would be so      
required and authorized under a Selling and Servicing Contract.                 

SERVICING COMPENSATION AND PAYMENT OF EXPENSES                                  

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer, the Seller/Servicers' primary     
compensation for their servicing activities will come from the payment to them  
or the retention by them, of an amount equal to the Servicing Fee for each      
Mortgage Loan. The Company's or Servicing Entity's, as applicable, primary      
compensation for supervising the mortgage servicing and advancing certain       
expenses of a Mortgage Pool will come from the payment to it, of an amount equal
to the Master Servicing Fee with respect to each Mortgage Loan (or a Mortgage   
Loan in its respective Mortgage Loan Servicing Group) in such Mortgage Pool. The
Master Servicing Fee and the Servicing Fee with respect to each payment of      
interest received on a Mortgage Loan will equal one-twelfth of the annual Master
Servicing Fee or Servicing Fee annual percentage, as applicable, set forth in   
the Pooling Agreement multiplied by the outstanding principal balance of such   
Mortgage Loan during the month for which such amount is computed. In addition to
the Servicing Fee and Master Servicing Fee, the Company, a Servicing Entity or a
Seller may retain as its Retained Yield the right to a portion of the interest  
payable on each Mortgage Loan calculated by subtracting the applicable          
Pass-Through Rate and related Servicing Fee and Master Servicing Fee from the   
applicable Mortgage Interest Rate.                                              

  With respect to Series of Certificates as to which there will be no Master
Servicer and the servicing of the Mortgage Loans will be performed by the       
Servicer, the Servicer's primary compensation for its                           

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servicing activities will come from the payment to it or its retention, with    
respect to each interest payment on a Mortgage Loan, of an amount equal to the  
Servicing Fee for such Mortgage Loan. The Servicing Fee with respect to each    
payment of interest received on a Mortgage Loan will equal one-twelfth of the   
Servicing Fee annual percentage set forth in the Pooling Agreement multiplied by
the outstanding principal balance of such Mortgage Loan during the month for    
which such amount is computed. In addition to the Servicing Fee, the Company or 
a Seller may retain as its Retained Yield the right to a portion of the interest
payable on each Mortgage Loan calculated by subtracting the related Servicing   
Fee, the Certificate Administrator Fee and the Certificate Interest Rate from   
the applicable Mortgage Interest Rate.                                          

  With respect to Series of Certificates as to which there will be no Master
Servicer and the servicing of the Mortgage Loans will be performed by the       
Servicer or with respect to each Series as to which both the Company and a      
Servicing Entity will act as Master Servicers, the Certificate Administrator's  
compensation for its administrative services will come from the payment to it,  
with respect to each interest payment on a Mortgage Loan, of an amount equal to 
the Certificate Administrator Fee for such Mortgage Loan. The Certificate       
Administrator Fee with respect to each payment of interest received on a        
Mortgage Loan will equal one-twelfth of the annual Certificate Administrator Fee
annual percentage set forth in the Pooling Agreement multiplied by the          
outstanding principal balance of such Mortgage Loan during the month for which  
such amount is computed, subject to any minimum fee as will be set forth in the 
applicable Prospectus Supplement.                                               

As principal payments are made on each Mortgage Loan, the outstanding   
principal balance of the Mortgage Loans will decline, and thus compensation to  
the Seller/Servicers and the related Master Servicer, or to the Servicer and the
Certificate Administrator with respect to Series of Certificates for which there
will be no Master Servicer or both the Company and a Servicing Entity will act  
as Master Servicers, and any Retained Yield will decrease as the Mortgage Loans 
amortize (subject to any minimum levels of such compensation set forth in the   
applicable Prospectus Supplement). Principal Prepayments and liquidations of    
Mortgage Loans prior to maturity will also cause servicing compensation to the  
Seller/Servicers and the Company and/or Servicing Entity, as applicable, as     
Master Servicer, or to the Servicer and the Certificate Administrator, as       
applicable, and any Retained Yield to decrease (subject to any minimum levels of
such compensation set forth in the applicable Prospectus Supplement).           

In addition to their primary compensation, the Seller/Servicers or the  
Servicer, as applicable, will retain all prepayment fees, assumption fees and   
late payment charges, to the extent collected from Mortgagors. The              
Seller/Servicers' or the Servicer's income from such charges will depend upon   
their origination and servicing policies.                                       

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer, the Company or Servicing Entity,  
as applicable, will pay all expenses incurred in connection with its activities 
as Master Servicer (subject to limited reimbursement as described below), which,
unless otherwise specified in the applicable Prospectus Supplement, will include
payment of the fees and disbursements of the Trustee, payment of premiums of any
Mortgage Pool Insurance Policy, Special Hazard Insurance Policy, certificate    
insurance policy, Fraud Bond or Bankruptcy Bond or the costs of obtaining or    
maintaining any Letter of Credit or Reserve Fund and payment of expenses        
incurred in connection with distributions and reports to Certificateholders of  
each Series.                                                                    

  With respect to Series of Certificates as to which there will be no Master
Servicer and the servicing of the Mortgage Loans will be performed by the       
Servicer, the Servicer will pay certain expenses incurred in connection with its
activities as Servicer (subject to limited reimbursement as described below),   
which, unless otherwise specified in the applicable Prospectus Supplement, will 
include payment of premiums of any Mortgage Pool Insurance Policy, Special      
Hazard Insurance Policy, certificate insurance policy, Fraud Bond or Bankruptcy 
Bond or the costs of maintaining any Letter of Credit or Reserve Fund. The      
Certificate Administrator will pay the fees and disbursements of the Trustee.   

As set forth in the preceding section, each Master Servicer and the     
Seller/Servicers, or the Servicer, as applicable, are entitled to reimbursement 
for certain expenses incurred by them in connection with the liquidation of     
related defaulted Mortgage Loans. Certificateholders of such Series will suffer 
no loss by reason of such expenses to the extent claims are paid under any      
applicable credit enhancements. In the event, however, that claims are not paid 
under such policies or alternative coverages, or if coverage has been exhausted,
Certificateholders of such Series will suffer a loss to the extent that the     
proceeds of                                                                     

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liquidation of a defaulted Mortgage Loan, after reimbursement of each such      
Master Servicer's and the Seller/Servicer's expenses, or the Servicer's         
expenses, as applicable, are less than the principal balance of such Mortgage   
Loan. In addition, each Master Servicer and the Seller/Servicers, or the        
Servicer, as applicable, are entitled to reimbursement of expenditures incurred 
by them in connection with the restoration of a related damaged Mortgaged       
Property, such right of reimbursement being prior to the rights of              
Certificateholders to receive any related Insurance Proceeds or Liquidation     
Proceeds.                                                                       

EVIDENCE AS TO COMPLIANCE                                                       

Except as may be specified in the applicable Prospectus Supplement, each
Pooling Agreement will provide that on or before April 30 of each year,         
beginning on the first April 30 that is at least six months after the Cut-Off   
Date, one or more firms of independent public accountants will furnish          
statements to the Trustee to the effect that, in connection with such firm's    
examination of the financial statements of the Company and/or Servicing Entity, 
as Master Servicer, or the Servicer, as applicable, as of the previous December 
31, nothing came to such firm's attention that indicated that the Company or    
Servicing Entity, as applicable, as Master Servicer, or the Servicer, as        
applicable, was not in compliance with specified sections of the Pooling        
Agreement, except for (i) such exceptions as such firm believes to be immaterial
and (ii) such other exceptions as are set forth in such statement.              

Except as may be provided in the applicable Prospectus Supplement, each 
Pooling Agreement will also provide for delivery to the Trustee of an annual    
statement signed by an officer of the Company and/or Servicing Entity, as Master
Servicer, or the Servicer, as applicable, to the effect that, based on a review 
of the Company's and/or Servicing Entity's, as Master Servicer, or the          
Servicer's activities during the preceding calendar year, to the best of such   
officer's knowledge the Company and/or Servicing Entity, as Master Servicer, or 
the Servicer, as applicable, has fulfilled its obligations under the Pooling    
Agreement throughout the preceding year or, if there has been a default in the  
fulfillment of any such obligations, specifying each such default and the nature
and status thereof.                                                             

CERTAIN MATTERS REGARDING THE MASTER SERVICER, THE                              
SERVICER, THE CERTIFICATE ADMINISTRATOR AND THE COMPANY                         

Except as may otherwise be specified in the applicable Prospectus       
Supplement, the Pooling Agreement for each Series will provide that neither the 
Company nor a Servicing Entity, as applicable, may resign from its obligations  
and duties thereunder as Master Servicer or, if applicable, Certificate         
Administrator, or that the Servicer, where applicable, may not resign from its  
obligations and duties thereunder, except upon determination that its duties    
thereunder are no longer permissible under applicable law. No such resignation  
will become effective until the Trustee or a successor has assumed the Company's
or Servicing Entity's, as applicable, master servicing obligations and duties,  
or, where applicable, the Servicer's obligations and duties, under such Pooling 
Agreement.                                                                      

   The Pooling Agreement for each Series will provide that neither the Company
nor any Master Servicer, or that, where applicable, neither the Servicer nor the
Certificate Administrator, nor any director, officer, employee or agent of the  
Company, any Master Servicer, the Servicer and the Certificate Administrator    
(where applicable) (the 'Indemnified Parties') will be under any liability to   
the Trust or the Certificateholders or the Trustee, any Seller/Servicer or      
others for any action taken by any Indemnified Party, any Seller/Servicer or the
Trustee in good faith pursuant to the Pooling Agreement, or for errors in       
judgment; provided, however, that neither the Company, the Master Servicer, the 
Servicer nor the Certificate Administrator nor any such person will be protected
against any liability which would otherwise be imposed by reason of willful     
misfeasance, bad faith or gross negligence in the performance of duties or by   
reason of reckless disregard of obligations and duties thereunder. The Pooling  
Agreement relating to each such Series will further provide that any Indemnified
Party is entitled to indemnification by the Trust and will be held harmless     
against any loss, liability or expense incurred in connection with any legal    
action relating to the Pooling Agreement or the Certificates, other than any    
loss, liability or expense related to any specific Mortgage Loan or Mortgage    
Loans (except any such loss, liability or expense otherwise reimbursable        
pursuant to the Pooling Agreement) and any loss, liability or expense incurred  
by reason of willful misfeasance, bad faith or gross negligence in the          
performance of duties thereunder or by reason of reckless disregard of          
obligations and duties thereunder. In addition, the Pooling Agreement for       

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each such Series will provide that neither the Company nor any Master Servicer  
or, where applicable, neither the Servicer nor the Certificate Administrator, is
under any obligation to appear in, prosecute or defend any legal action which is
not incidental to its responsibilities under the Pooling Agreement and which in 
its opinion may involve it in any expense or liability. The Company or, where   
applicable, a Master Servicer or the Servicer or the Certificate Administrator, 
may, however, in its discretion, undertake any such action which it may deem    
necessary or desirable with respect to the Pooling Agreement and the rights and 
duties of the parties thereto and the interests of the Certificateholders       
thereunder. In such event, the legal expenses and costs of such action and any  
liability resulting therefrom will be expenses, costs and liabilities of the    
Trust, and the Company or, where applicable, a Master Servicer, the Servicer or 
the Certificate Administrator, will be entitled to be reimbursed therefor and to
charge the Certificate Account.                                                 

Any person into which a Master Servicer, the Servicer or the Certificate
Administrator may be merged, converted or consolidated, or any person resulting 
from any merger, conversion or consolidation to which such Master Servicer, the 
Servicer or the Certificate Administrator is a party, or any person succeeding  
to the business of such Master Servicer, the Servicer or the Certificate        
Administrator, will be the successor of such Master Servicer, the Servicer or   
the Certificate Administrator, respectively, under the Pooling Agreement.       

EVENTS OF DEFAULT                                                               

With respect to Series of Certificates as to which the Company and/or a 
Servicing Entity will act as Master Servicer, Events of Default under the       
Pooling Agreement for each such Series (but, in the event that both the Company 
and a Servicing Entity are acting as Master Servicers for a Series, such Event  
of Default shall apply only to the defaulting Master Servicer), unless otherwise
specified in the applicable Prospectus Supplement, will include, without        
limitation, (i) any failure by the Company or Servicing Entity, as applicable,  
as Master Servicer, to make a required deposit to the Certificate Account or, if
the Company or Servicing Entity, as applicable, as Master Servicer, is the      
Paying Agent, to distribute to Certificateholders of any Class any required     
payment which continues unremedied for five business days after the giving of   
written notice of such failure to the Company or Servicing Entity, as           
applicable, as Master Servicer, by the Trustee, or to the Company or Servicing  
Entity, as applicable, as Master Servicer, and the Trustee by the holders of    
Certificates for that Series evidencing interests aggregating not less than 25% 
of the assets of the Trust, as determined in the manner set forth in such       
Pooling Agreement; (ii) any failure on the part of the Company or Servicing     
Entity, as applicable, as Master Servicer, duly to observe or perform in any    
material respects any other of the covenants or agreements on the part of the   
Company or Servicing Entity, as applicable, as Master Servicer, contained in the
Certificates for that Series or in such Pooling Agreement which continues       
unremedied for 60 days after the giving of written notice of such failure to the
Company or Servicing Entity, as applicable, as Master Servicer, by the Trustee, 
or to the Company or Servicing Entity, as applicable, as Master Servicer, and   
the Trustee by the holders of Certificates for that Series evidencing interests 
aggregating not less than 25% of the assets of the Trust, as determined in the  
manner set forth in such Pooling Agreement; (iii) certain events of insolvency, 
readjustment of debt, marshalling of assets and liabilities or similar          
proceedings and certain actions by the Company or Servicing Entity, as          
applicable, as Master Servicer, indicating insolvency, reorganization or        
inability to pay its obligations and (iv) any failure of the Company or         
Servicing Entity, as applicable, to make any Advance (other than a              
Nonrecoverable Advance) which continues unremedied at the opening of business on
the Distribution Date in respect of which such Advance was to have been made.   
With respect to Series of Certificates as to which there will be no Master      
Servicer, the Events of Default under the Pooling Agreement for each such       
Series, unless otherwise specified in the applicable Prospectus Supplement, will
be the same failures by or conditions of the Servicer as will constitute Events 
of Default by a Master Servicer under the Pooling Agreement for each Series of  
Certificates for which the Company and/or a Servicing Entity will act as Master 
Servicer, except that an Event of Default created by a failure of a Master      
Servicer to make a required deposit to the Certificate Account referred to in   
clause (i) of the immediately prior sentence will instead be the failure of the 
Servicer to make a required deposit to the Investment Account on the Withdrawal 
Date. Notwithstanding the foregoing, if an Event of Default described in clause 
(iv) above occurs, the Trustee will, upon written notice to the Company or      
Servicing Entity, as applicable, immediately suspend all of the rights and      
obligations of the Company or Servicing Entity, as applicable, thereafter       
arising under the Pooling Agreement and the Trustee will act to carry out       

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the duties of the Master Servicer, including the obligation to make any Advance 
the nonpayment of which was an Event of Default described in clause (iv) above. 
The Trustee will permit the Company or Servicing Entity, as applicable, to      
resume its rights and obligations as Master Servicer under the Pooling Agreement
if the Company or Servicing Entity, as applicable, within two Business Days     
following its suspension, remits to the Trustee the amount of any Advance the   
nonpayment of which was an Event of Default described in clause (iv) above. If  
an Event of Default as described in clause (iv) above occurs more than two times
in any twelve month period, the Trustee will not be obligated to permit the     
Company or Servicing Entity, as applicable, to resume its rights and obligations
as Master Servicer under the Pooling Agreement.                                 

RIGHTS UPON EVENT OF DEFAULT                                                    

 As long as an Event of Default under the Pooling Agreement for any Series
remains unremedied, the Trustee or holders of Certificates for that Series      
evidencing interests aggregating not less than 25% of the assets of the Trust,  
as determined in the manner set forth in such Pooling Agreement, may terminate  
all of the rights and obligations of the defaulting Master Servicer, the        
Servicer or the Certificate Administrator, as applicable, under such Pooling    
Agreement and in and to the Trust, whereupon the Trustee will succeed to all the
responsibilities, duties and liabilities of the Master Servicer, the Servicer or
the Certificate Administrator, as applicable, under such Pooling Agreement and  
will be entitled to similar compensation arrangements and limitations on        
liability. In the event that the Trustee is unwilling or unable so to act, it   
may appoint or petition a court of competent jurisdiction for the appointment of
a housing and home finance institution with a net worth of at least $10,000,000 
to act as successor to the defaulting Master Servicer, the Servicer or the      
Certificate Administrator, as applicable, under such Pooling Agreement. Pending 
any such appointment, the Trustee is obligated to act in such capacity. In the  
event the Trustee acts as successor to such Master Servicer or the Servicer, the
Trustee will be obligated to make Advances unless it is prohibited by law from  
doing so. The Trustee and such successor may agree upon the compensation to be  
paid, which in no event may be greater than the compensation to the Company or  
Servicing Entity, as applicable, as initial Master Servicer, or with respect to 
a Series of Certificates as to which there will be no Master Servicer, to the   
Servicer named in the applicable Prospectus Supplement or the Certificate       
Administrator, as applicable, under such Pooling Agreement. Subject to certain  
limitations, holders of Certificates for a Series evidencing interests          
aggregating not less than 25% of the assets of the Trust, as determined in the  
manner set forth in the Pooling Agreement for that Series, may direct the action
of the Trustee in pursuing remedies and exercising powers under such Pooling    
Agreement.                                                                      

   No Certificateholder of any Series will have any right under the applicable
Pooling Agreement to institute any proceeding with respect to such Pooling      
Agreement unless such Certificateholder previously has given to the Trustee     
written notice of default and unless the holders of Certificates for that Series
evidencing interests aggregating not less than 25% of the assets of the Trust,  
as determined in the manner set forth in such Pooling Agreement, have made      
written request upon the Trustee to institute such proceeding in its own name as
Trustee thereunder and have offered to the Trustee reasonable indemnity and the 
Trustee for 60 days has neglected or refused to institute any such proceeding.  
However, the Trustee is under no obligation to exercise any of the trusts or    
powers vested in it by the Pooling Agreement for any Series or to make any      
investigation of matters arising thereunder or to institute, conduct or defend  
any litigation thereunder or in relation thereto at the request, order or       
direction of any of the Certificateholders, unless such Certificateholders have 
offered to the Trustee reasonable security or indemnity against the costs,      
expenses and liabilities which may be incurred therein or thereby.              

AMENDMENT                                                                       

    The Pooling Agreement for each Series may be amended by the Company and/or a
Servicing Entity and the Trustee, with respect to Series of Certificates as to  
which the Company and/or a Servicing Entity will act as Master Servicer (and in 
the case where both the Company and a Servicing Entity are acting as Master     
Servicers, the Certificate Administrator), and by the Company, the Servicer, the
Certificate Administrator and the Trustee with respect to Series of Certificates
as to which there will be no Master Servicer, without the consent of any of the 
Certificateholders covered by such Pooling Agreement, (i) to cure any ambiguity,
(ii) to correct or supplement any provision therein which may be defective or   

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inconsistent with any other provision therein, (iii) to comply with any         
requirements imposed by the Internal Revenue Code of 1986, as amended (the      
'Code') or any regulations thereunder, including provisions to such extent as   
shall be necessary to maintain the qualification of certain assets of the Trust 
as a REMIC or to avoid or minimize the risk of imposition of any tax on the     
related Trust, (iv) to correct the description of any property at any time owned
by the Trust, or to assure conveyance to the Trust of any property to be        
included as assets of the Trust, (v) to modify, add to or eliminate certain     
provisions set forth in the Pooling Agreement relating to the form of           
Certificates and restrictions on transfer of the REMIC Residual Certificates and
(vi) to add any provision to, or amend any provision in, the Pooling Agreement, 
provided that such addition or amendment does not adversely affect in any       
material respect the interests of any Certificateholder.                        

    The Pooling Agreement for each Series may also be amended by the Company and
the Trustee, with respect to Series of Certificates as to which the Company will
act as Master Servicer, and by the Company, the Servicer, the Certificate       
Administrator and the Trustee with respect to Series of Certificates as to which
the Company will not act as Master Servicer, with the consent of the holders of 
Certificates for that Series evidencing interests aggregating not less than 66% 
of the assets of the Trust, as determined in the manner set forth in such       
Pooling Agreement, for the purpose of adding any provisions to or changing in   
any manner or eliminating any of the provisions of such Pooling Agreement or of 
modifying in any manner the rights of the holders of Certificates of that       
Series; provided, however, that no such amendment may (i) reduce in any manner  
the amount of, or delay the timing of, payments received on Mortgage Loans which
are required to be distributed in respect of any Certificate without the consent
of the holder of such Certificate, or (ii) reduce the aforesaid percentage of   
Certificates, the holders of which are required to consent to any such amendment
without the consent of the holders of all Certificates of such Series then      
outstanding.                                                                    

The Prospectus Supplement for a particular Series may describe other or 
different provisions concerning conditions to the amendment of the related      
Pooling Agreement.                                                              

LIST OF CERTIFICATEHOLDERS                                                      

    With respect to Series of Certificates as to which the Company will act as a
Master Servicer or with respect to a Series where a Servicing Entity is the only
Master Servicer, upon written request of the Trustee, the Company or Servicing  
Entity as applicable, will provide to the Trustee within 30 days after the      
receipt of such request a list of the names and addresses of all                
Certificateholders of record of a particular Series or Class as of the most     
recent Record Date for payment of distributions to Certificateholders of that   
Series or Class. Upon written request of three or more Certificateholders of    
record of such a Series of Certificates, for purposes of communicating with     
other Certificateholders with respect to their rights under the Pooling         
Agreement for such Series, the Trustee will afford such Certificateholders      
access during business hours to the most recent list of Certificateholders of   
that Series held by the Trustee. If such list is as of a date more than 90 days 
prior to the date of receipt of such Certificateholders' request, the Trustee   
shall promptly request from the Master Servicer a current list and will afford  
such requesting Certificateholders access to such list promptly upon receipt.   
With respect to Series of Certificates as to which there will be no Master      
Servicer, the Company, as Certificate Administrator, will provide the list of   
names and addresses of the Certificateholders described above in the same manner
as so described.                                                                

TERMINATION                                                                     

The obligations created by the Pooling Agreement for each Series will   
terminate upon the occurrence of both (i) the later of the maturity or other    
liquidation of the last Mortgage Loan subject thereto and the disposition of all
property acquired upon foreclosure of any Mortgage Loan and (ii) the payment to 
Certificateholders of each Class, if any, of that Series of all amounts held on 
behalf of such Certificateholders and required to be paid to them pursuant to   
such Pooling Agreement. The Pooling Agreement for each Series will permit, but  
not require, the Company to repurchase from the Trust for such Series all       
remaining Mortgage Loans at a price equal to the unpaid principal amount thereof
or the Trust's adjusted basis in the Mortgage Loans, as described in the related
Prospectus Supplement, in either case together with interest at the applicable  
Mortgage Interest Rates (which will generally be passed                         

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through to Certificateholders at the applicable Pass-Through Rates). The        
exercise of such right will effect early retirement of the Certificates of such 
Series, but the Company's right so to repurchase is subject to the aggregate    
principal balances of the Mortgage Loans at the time of repurchase being less   
than the percentage specified in the related Prospectus Supplement of the       
aggregate principal amount of the Mortgage Loans underlying the Certificates of 
such Series as of the Cut-Off Date. In no event, however, will the trust created
by any Pooling Agreement continue beyond the expiration of 21 years from the    
death of the survivor of the issue of the person named in such Pooling          
Agreement. For each Series, the Trustee will give written notice of termination 
of the Pooling Agreement to each Certificateholder, and the final distribution  
will be made only upon surrender and cancellation of the Certificates at an     
office or agency specified in the notice of termination.                        

REDEMPTION AGREEMENT                                                            

    If so specified in the Prospectus Supplement for a Series, the related Trust
will enter into a redemption agreement pursuant to which the counterparty to the
agreement will have the right to cause a redemption of the outstanding          
Certificates of such Series, beginning on the Distribution Date and subject to  
payment of the redemption price and other conditions specified in the Prospectus
Supplement. In general, the redemption price will equal the aggregate           
outstanding principal balance of all Certificates of such Series (other than    
such Certificates with a notional principal balance), plus any interest         
described in the Prospectus Supplement. Payment of the redemption price will be 
in lieu of any distribution of principal and interest that would otherwise be   
made on that Distribution Date. Upon a redemption, the holder of the redemption 
right will receive the assets of the Trust and each Certificateholder will      
receive the outstanding principal balance of its Certificate (other than a      
holder of Certificates with a notional principal balance), plus any interest    
specified in the Prospectus Supplement. See 'Yield, Prepayment and Maturity     
Considerations' for a discussion of the effects of such a redemption of an      
investor's yield to maturity. In the case of a Trust for which a REMIC election 
or elections have been made, the transaction by which the Certificates are      
retired and the related redemption is conducted will constitute a 'qualified    
liquidation' under Section 860F of the Code.                                    

PUT OPTION                                                                      

If so specified in the Prospectus Supplement for a Series, each         
Certificateholder of such Series, of a Class of such Series or of a group for   
such Series will have the option to require the entity named in such Prospectus 
Supplement to purchase such Certificates in full on the date, at the purchase   
price and on the terms specified in such Prospectus Supplement.                 

THE TRUSTEE                                                                     

The Trustee under each Pooling Agreement will be named in the related   
Prospectus Supplement. The bank or trust company serving as Trustee may have    
normal banking relationships with the Company and/or its affiliates. The Trustee
will have combined capital and surplus of not less than $50 million.            

 The Trustee under each Pooling Agreement may resign at any time, in which
event the Company will be obligated to appoint a successor Trustee. The Company 
may also remove the Trustee if the Trustee ceases to be eligible to continue as 
such under the applicable Pooling Agreement or if the capital and surplus of the
Trustee is reduced below $50 million. Upon becoming aware of such circumstances,
the Company will be obligated to appoint a successor Trustee for the related    
Series. The Trustee may also be removed at any time by holders of Certificates  
of a Series evidencing more than 50% of the aggregate undivided interests in the
related Trust. Any resignation or removal of the Trustee and appointment of a   
successor Trustee will not become effective until acceptance of the appointment 
by the successor Trustee.                                                       

With respect to Series of Certificates for which the Trust will be a    
Delaware business trust, the Delaware trustee will be named in the related      
Prospectus Supplement. The Delaware trustee may have normal banking             
relationships with the Company and/or its affiliates.                           

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PRIMARY INSURANCE, FHA MORTGAGE INSURANCE, VA MORTGAGE GUARANTY, HAZARD 
INSURANCE; CLAIMS THEREUNDER

As set forth below, a Mortgage Loan may be required to be covered by a  
hazard insurance policy and either an FHA Insurance Policy, a VA Guaranty or a  
Primary Insurance Policy. The following is only a brief description of such     
coverage and does not purport to describe all of the characteristics of each    
type of insurance. Such insurance is subject to underwriting and approval of    
individual Mortgage Loans by the respective insurers and guarantors. In some    
cases, however, the issuer of the insurance or guaranty may delegate            
underwriting authority to the originator of the Mortgage Loan. The descriptions 
of any insurance coverage in this Prospectus or any Prospectus Supplement do not
purport to be complete and are qualified in their entirety by reference to such 
forms of policies, and to such statutes or regulations as may be applicable.    

PRIMARY INSURANCE                                                               

Unless otherwise specified in the applicable Prospectus Supplement, each
Mortgage Loan with a loan-to-value ratio at origination and at the Cut-Off Date 
greater than 80% will be covered by a primary mortgage insurance policy (a      
'Primary Insurance Policy') providing insurance coverage against default on such
Mortgage Loan, in general, of up to 25% of the principal balance of such        
Mortgage Loan with maintenance requirements in certain cases for the remaining  
term of such Mortgage Loan, but at least until the loan-to-value ratio drops to 
80%. Conversely, Mortgage Loans with lower loan-to-value ratios (up to          
approximately 80%) may not be covered by any Primary Insurance Policies.        
Applicable state laws may in some instances limit the maximum coverage which may
be obtained with respect to certain Mortgage Loans. Any such policy will be     
issued by a Qualified Insurer.                                                  

While the terms and conditions of the Primary Insurance Policies will   
differ, each Primary Insurance Policy will in general provide substantially the 
following coverage. The amount of the loss as calculated under a Primary        
Insurance Policy covering a Mortgage Loan (herein referred to as the 'Loss')    
will generally consist of the unpaid principal balance of such Mortgage Loan and
accrued and unpaid interest thereon and reimbursement of certain expenses, less 
(i) rents or other payments collected or received by the insured (other than the
proceeds of hazard insurance) that are derived from the related Mortgaged       
Property, (ii) hazard insurance proceeds in excess of the amount required to    
restore such Mortgaged Property and which have not been applied to the payment  
of the Mortgage Loan, (iii) certain amounts expended by the insured but not     
approved by the insurer, (iv) claim payments previously made on such Mortgage   
Loan and (v) unpaid premiums and certain other amounts.                         

  The issuer of a Primary Insurance Policy will generally be required to pay
either: (i) the insured percentage of the Loss; (ii) the entire amount of the   
Loss, after receipt by the insurer of good and merchantable title to, and       
possession of, the Mortgaged Property; or (iii) at the option of the insurer    
under certain Primary Insurance Policies, the sum of the delinquent monthly     
payments plus any advances made by the insured, both to the date of the claim   
payment and, thereafter, monthly payments in the amount that would have become  
due under the Mortgage Loan if it had not been discharged plus any advances made
by the insured until the earlier of (a) the date the Mortgage Loan would have   
been discharged in full if the default had not occurred or (b) an approved sale.

   As conditions precedent to the filing or payment of a claim under a Primary
Insurance Policy, in the event of default by the Mortgagor, the insured will    
typically be required, among other things, to: (i) advance or discharge (a)     
hazard insurance premiums and (b) as necessary and approved in advance by the   
insurer, real estate taxes, protection and preservation expenses and foreclosure
and related costs; (ii) in the event of any physical loss or damage to the      
Mortgaged Property, have the Mortgaged Property restored to at least its        
condition at the effective date of the Primary Insurance Policy (ordinary wear  
and tear excepted); and (iii) tender to the insurer good and merchantable title 
to, and possession of, the Mortgaged Property. If any Advance to be made        
(including expenses to be paid) by the Master Servicer as a condition for       
coverage of a loss by a Primary Insurance Policy is not so made by the Master   
Servicer because the such Advance has been determined to be nonrecoverable, then
such loss will be allocated to the Certificateholders. See 'Description of      
Certificates -- Advances'.                                                      

For any Certificates offered hereunder as to which the Company and/or a 
Servicing Entity will act as Master Servicer, the Company or Servicing Entity,  
as applicable, will cause each Servicer to maintain, or                         

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with respect to a Series of Certificates as to which there will be no Master    
Servicer, the Servicer will maintain, in full force and effect and to the extent
coverage is available a Primary Insurance Policy with regard to each Mortgage   
Loan for which such coverage is required under the standard described above,    
provided that such Primary Insurance Policy was in place as of the Cut-Off Date 
and the Company or Servicing Entity, as applicable, had knowledge of such       
Primary Insurance Policy. With respect to Series of Certificates as to which the
Company and/or a Servicing Entity will act as Master Servicer, in the event that
the Company or Servicing Entity, as applicable learns that a Mortgage Loan had a
loan-to-value ratio at origination and as of the Cut-Off Date in excess of 80%  
and was not the subject of a Primary Insurance Policy (and was not included in  
any exception to such standard disclosed in the related Prospectus Supplement), 
then the Company or Servicing Entity, as applicable is required to use its      
reasonable efforts to obtain and maintain a Primary Insurance Policy to the     
extent that such a policy is obtainable at a reasonable price. With respect to  
Series of Certificates as to which there will be no Master Servicer, in the     
event the Servicer learns of the lack of a Primary Insurance Policy described in
the preceding sentence, the Servicer shall notify the Trustee who shall require 
the Seller to obtain a Primary Insurance Policy, repurchase the Mortgage Loan or
substitute a mortgage loan for the applicable Mortgage Loan. The Company or     
Servicing Entity, as Master Servicer, or the Servicer, as applicable, will not  
cancel or refuse to renew any such Primary Insurance Policy in effect at the    
time of the initial issuance of a Series of Certificates that is required to be 
kept in force under the applicable Pooling Agreement unless, in the event that  
such Series of Certificates was rated at the time of issuance, the replacement  
Primary Insurance Policy from such cancelled or non-renewed policy is maintained
with an insurer whose claims-paying ability is acceptable to the rating agency  
or agencies that rated such Series of Certificates for mortgage pass-through    
certificates having a rating equal to or better than the then-current ratings of
such Series of Certificates.                                                    

 Evidence of each Primary Insurance Policy will be provided to the Trustee
simultaneously with the transfer to the Trust of the related Mortgage Loan. With
respect to Series of Certificates as to which the Company and/or a Servicing    
Entity will act as Master Servicer, under the Selling and Servicing Contract    
each Seller/Servicer, on behalf of itself, the Company, the related Master      
Servicer, the Trust and the Certificateholders, will be required to present     
claims to the insurer under any Primary Insurance Policy and take such          
reasonable steps as are necessary to permit recovery thereunder with respect to 
defaulted Mortgage Loans. Amounts collected by a Seller/Servicer under such     
Primary Insurance Policy shall be deposited in the Custodial Account for P&I    
maintained by such Seller/Servicer on behalf of the Company, the Master         
Servicer, the Trust and the Certificateholders. The Company or Servicing Entity,
as applicable, will agree to cause each Seller/Servicer not to cancel or refuse 
to renew any Primary Insurance Policy required to be kept in force by the       
Pooling Agreement. With respect to Series of Certificates as to which there will
be no Master Servicer, under the Pooling Agreement the Servicer will agree not  
to cancel or refuse to renew any Primary Insurance Policy and will be required  
to present claims to the insurer under any such Primary Insurance Policy, take  
steps to permit recovery under any such Primary Insurance Policy and deposit    
amounts collected thereunder in the Custodial Account for P&I to the same extent
as a Seller/Servicer will be so required under a Selling and Servicing Contract.

The Pooling Agreement will permit the cancellation or non-renewal of a  
Primary Insurance Policy in the event that the loan-to-value ratio of the       
Mortgage Loan based on the original appraisal or a current appraisal is less    
than 80% of the then current outstanding principal balance of such Mortgage     
Loan.                                                                           

   See 'Description of Credit Enhancements -- The Fraud Bond' for a discussion
of the possible effect of fraudulent conduct or negligence by the Seller, the   
Seller/Servicer or the Mortgagor with respect to a Mortgage Loan on the coverage
of a Primary Insurance Policy.                                                  

FHA MORTGAGE INSURANCE                                                          

    The National Housing Act of 1934, as amended (the 'Housing Act'), authorizes
various FHA mortgage insurance programs. Some of the Mortgage Loans may be      
insured under either Section 203(b), Section 234 or Section 235 of the Housing  
Act. Under Section 203(b), FHA insures mortgage loans of up to 30 years'        
duration for the purchase of one- to four-family dwelling units. Mortgage Loans 
for the purchase of condominium units are insured by FHA under Section 234.     
Loans insured under these programs must bear interest at a rate not exceeding   
the maximum rate in effect at the time the loan is made, as established by the  
United States Department of Housing and Urban Development ('HUD'), and          

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may not exceed specified percentages of the lesser of the appraised value of the
property and the sales price, less seller paid closing costs for the property,  
up to certain specified maximums. In addition, FHA imposes initial investment   
minimums and other requirements on mortgage loans insured under the Section     
203(b) and Section 234 programs.                                                

  Under Section 235, assistance payments are paid by HUD to the mortgagee on
behalf of eligible mortgagors for as long as the mortgagors continue to be      
eligible for the payments. To be eligible, a mortgagor must be part of a family,
must have income within the limits prescribed by HUD at the time of initial     
occupancy, must occupy the property and must meet requirements for              
recertification at least annually.                                              

    The regulations governing these programs provide that insurance benefits are
payable either (i) upon foreclosure (or other acquisition of possession) and    
conveyance of the mortgaged premises to HUD or (ii) upon assignment of the      
defaulted mortgage loan to HUD. The FHA insurance that may be provided under    
these programs upon conveyance of the home to HUD is equal to 100% of the       
outstanding principal balance of the mortgage loan, plus accrued interest, as   
described below, and certain additional costs and expenses. When entitlement to 
insurance benefits results from assignment of the mortgage loan to HUD, the     
insurance payment is computed as of the date of the assignment and includes the 
unpaid principal amount of the mortgage loan plus mortgage interest accrued and 
unpaid to the assignment date.                                                  

 When entitlement to insurance benefits results from foreclosure (or other
acquisition of possession) and conveyance, the insurance payment is equal to the
unpaid principal amount of the mortgage loan, adjusted to reimburse the         
mortgagee for certain tax, insurance and similar payments made by it and to     
deduct certain amounts received or retained by the mortgagee after default, plus
reimbursement not to exceed two-thirds of the mortgagee's foreclosure costs.    

VA MORTGAGE GUARANTY                                                            

The Servicemen's Readjustment Act of 1944, as amended, permits a veteran
(or, in certain instances, his or her spouse) to obtain a mortgage loan guaranty
by the VA covering mortgage financing of the purchase of a one-to four-family   
dwelling unit to be occupied as the veteran's home at an interest rate not      
exceeding the maximum rate in effect at the time the loan is made, as           
established by HUD. The program has no limit on the amount of a mortgage loan,  
requires no down payment from the purchaser and permits the guaranty of mortgage
loans with terms limited by the estimated economic life of the property, up to  
30 years. The maximum guaranty that may be issued by the VA under this program  
is 50% of the original principal amount of the mortgage loan up to a certain    
dollar limit established by the VA. The loan-to-value ratios allowed for        
VA-guaranteed loans are set forth in the FNMA Seller's Guide. The liability on  
the guaranty is reduced or increased pro rata with any reduction or increase in 
the amount of indebtedness, but in no event will the amount payable on the      
guaranty exceed the amount of the original guaranty. Notwithstanding the dollar 
and percentage limitations of the guaranty, a mortgagee will ordinarily suffer a
monetary loss only where the difference between the unsatisfied indebtedness and
the proceeds of a foreclosure sale of mortgaged premises is greater than the    
original guaranty as adjusted. The VA may, at its option, and without regard to 
the guaranty, make full payment to a mortgagee of the unsatisfied indebtedness  
on a mortgage upon its assignment to the VA.                                    

Since there is no limit imposed by the VA on the principal amount of a  
VA-guaranteed mortgage loan but there is a limit on the amount of the VA        
guaranty, additional coverage under a Primary Insurance Policy may be required  
by the Company for VA loans in excess of certain amounts. The amount of any such
additional coverage will be set forth in the related Prospectus Supplement.     

HAZARD INSURANCE                                                                

Unless otherwise specified in the applicable Prospectus Supplement, each
Seller/Servicer with respect to Series of Certificates as to which the Company  
and/or a Servicing Entity will act as Master Servicer, or the Servicer with     
respect to Series of Certificates as to which there will be no Master Servicer, 
will cause to be maintained for each Mortgage Loan (other than Cooperative Loans
and Mortgage Loans secured by condominium units) that it services a hazard      
insurance policy providing for no less than the coverage of the standard form of
fire insurance policy with extended coverage customary in the state in          

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which the Mortgaged Property is located. Such coverage will be in an amount not 
less than the maximum insurable value of the Mortgaged Property or the original 
principal balance of such Mortgage Loan, whichever is less. As set forth above, 
all amounts collected by the Company or Servicing Entity, as applicable, as     
Master Servicer, or a Seller/Servicer, or the Servicer, as applicable, under any
hazard policy (except for amounts to be applied to the restoration or repair of 
the Mortgaged Property or released to the Mortgagor in accordance with the      
Seller/Servicer's or the Servicer's normal servicing procedures) will be        
deposited in the Custodial Account for P&I. In the event that the Company or    
Servicing Entity, as applicable, as Master Servicer, or the Seller/Servicer, or 
the Servicer, as applicable, maintains a blanket policy insuring against hazard 
losses on all of the Mortgage Loans, it shall conclusively be deemed to have    
satisfied its obligation relating to the maintenance of hazard insurance. Such  
blanket policy may contain a deductible clause, in which case the Company or    
Servicing Entity, as applicable, as Master Servicer, or the Seller/Servicer, or 
the Servicer, as applicable, will deposit in the Custodial Account for P&I or   
the Certificate Account all sums which would have been deposited therein but for
such clause. The Company or Servicing Entity, as applicable, as Master Servicer,
and each of the Seller/Servicers with respect to Series of Certificates as to   
which the Company and/or a Servicing Entity will act as Master Servicer, or the 
Servicer with respect to Series of Certificates as to which there will be no    
Master Servicer, are required to maintain a fidelity bond and errors and        
omissions policy with respect to officers and employees which provide coverage  
against losses which may be sustained as a result of an officer's or employee's 
misappropriation of funds or errors and omissions in failing to maintain        
insurance, subject to certain limitations as to amount of coverage, deductible  
amounts, conditions, exclusions and exceptions in such form and amount as       
specified in the Servicing Contract or the Pooling Agreement, as applicable.    

 In general, the standard form of fire and extended coverage policy covers
physical damage to or destruction of the improvements on the property by fire,  
lightning, explosion, smoke, windstorm and hail, and riot, strike and civil     
commotion, subject to the conditions and exclusions particularized in each      
policy. Although the policies relating to the Mortgage Loans will be            
underwritten by different insurers under different state laws in accordance with
different applicable state forms and therefore will not contain identical terms 
and conditions, the basic terms thereof are dictated by respective state laws,  
and most such policies typically do not cover any physical damage resulting from
the following: war, revolution, governmental actions, floods and other          
water-related causes, earth movement (including earthquakes, landslides and mud 
flows), nuclear reactions, wet or dry rot, vermin, rodents, insects or domestic 
animals, theft and, in certain cases, vandalism. The foregoing list is merely   
indicative of certain kinds of uninsured risks and is not intended to be        
all-inclusive. The Company or Servicing Entity, as applicable, may require      
Mortgaged Properties in certain locations to be covered by policies of          
earthquake insurance, to the extent it is reasonably available. When any        
improvement to a Mortgaged Property is located in a designated flood area and in
a community which participates in the National Flood Insurance Program at the   
time of origination of the related Mortgage Loan, and flood insurance is        
required and available, the Pooling Agreement requires the Company or Servicing 
Entity, as applicable, as Master Servicer, through the Seller/Servicer          
responsible for servicing such Mortgage Loan, or the Servicer, as applicable, to
cause the Mortgagor to acquire and maintain such insurance.                     

 The hazard insurance policies covering the Mortgaged Properties typically
contain a clause which, in effect, requires the insured at all times to carry   
insurance of a specified percentage (generally 80% to 90%) of the full          
replacement value of the improvements on the property in order to recover the   
full amount of any partial loss. If the insured's coverage falls below this     
specified percentage, such clause provides that the insurer's liability in the  
event of partial loss does not exceed the larger of (i) the replacement cost of 
the improvements less physical depreciation, and (ii) such proportion of the    
loss, without deduction for depreciation, as the amount of insurance carried    
bears to the specified percentage of the full replacement cost of such          
improvements.                                                                   

Neither the Seller/Servicer with respect to Series of Certificates as to
which the Company and/or a Servicing Entity will act as Master Servicer, or the 
Servicer with respect to Series of Certificates as to which there will be no    
Master Servicer, will require that a hazard or flood insurance policy be        
maintained for any Cooperative Loan or Mortgage Loan secured by a condominium   
unit. With respect to a Cooperative Loan, generally the Cooperative itself is   
responsible for maintenance of hazard insurance for the property owned by the   
Cooperative, and the tenant-stockholders of the Cooperative do not maintain     
individual hazard insurance policies. To the extent, however, that a Cooperative
and the related borrower                                                        

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on a Cooperative Note do not maintain such insurance or do not maintain adequate
coverage or any insurance proceeds are not applied to the restoration of the    
damaged property, damage to such borrower's cooperative apartment or such       
Cooperative's building could significantly reduce the value of the collateral   
securing such Cooperative Note. With respect to a Mortgage Loan secured by a    
condominium unit, the condominium owner's association for the related building  
generally is responsible for maintenance of hazard insurance for such building, 
and the condominium owners do not maintain individual hazard insurance policies.
To the extent that the owner of a Mortgage Loan secured by a condominium unit   
and the related condominium owner's association do not maintain such insurance  
or do not maintain adequate coverage or any insurance proceeds are not applied  
to the restoration of the damaged property, damage to such borrower's           
condominium unit or the related building could significantly reduce the value of
the Mortgaged Property.                                                         

Since the amount of hazard insurance a Master Servicer or the           
Seller/Servicers, or the Servicer, as applicable, will cause to be maintained on
the Mortgaged Properties declines as the principal balances owing on the related
Mortgage Loans decrease, and since residential properties have historically     
appreciated in value over time, in the event of partial loss, hazard insurance  
proceeds may be insufficient to restore fully the damaged property. See         
'Description of Credit Enhancements -- Special Hazard Insurance' for a          
description of the limited protection afforded by the Special Hazard Insurance  
Policy, Letter of Credit or Reserve Fund, if any is obtained, against losses    
occasioned by certain hazards which are otherwise uninsured against, as well as 
against losses caused by the application of the clause described in the         
preceding paragraph.                                                            

 Any losses incurred with respect to Mortgage Loans due to uninsured risks
(including earthquakes, mudflows and floods) or insufficient hazard insurance   
proceeds could affect distributions to the Certificateholders.                  

DESCRIPTION OF CREDIT ENHANCEMENTS

To the extent provided in the applicable Prospectus Supplement, credit  
enhancement for each Series of Certificates may be comprised of one or more of  
the following components, each of which will have a dollar limit. Credit        
enhancement components may include coverage with respect to losses that are (i) 
attributable to the Mortgagor's failure to make any payment of principal or     
interest as required under the Mortgage Note, but not including Special Hazard  
Losses, Extraordinary Losses (as defined below) or other losses resulting from  
damage to a Mortgaged Property, Bankruptcy Losses or Fraud Losses (any such     
loss, a 'Defaulted Mortgage Loss'); (ii) of a type generally covered by a       
Special Hazard Insurance Policy (any such loss, a 'Special Hazard Loss');       
(iii) attributable to certain actions which may be taken by a bankruptcy court  
in connection with a Mortgage Loan, including a reduction by a bankruptcy court 
of the principal balance of or the Mortgage Interest Rate on a Mortgage Loan or 
an extension of its maturity (any such loss, a 'Bankruptcy Loss'); (iv) incurred
on defaulted Mortgage Loans as to which there was fraudulent conduct or         
negligence by either the Seller, the Seller/Servicer, the Servicer or the       
Mortgagor in connection with such Mortgage Loans (any such loss, a 'Fraud       
Loss'); and (v) attributable to shortfalls in the payment of amounts due to one 
or more Classes of Certificates. Losses occasioned by war, civil insurrection,  
certain governmental actions, nuclear reaction, chemical contamination, errors  
in design, faulty workmanship or materials or waste by the Mortgagor            
('Extraordinary Losses') will not be covered. To the extent that the credit     
enhancement for any Series of Certificates is exhausted, the Certificateholders 
will bear all further risks of loss not otherwise insured against.              

    As set forth below and in the applicable Prospectus Supplement, (i) coverage
with respect to Defaulted Mortgage Losses may be provided by one or more of a   
Letter of Credit, Reserve Fund or a Mortgage Pool Insurance Policy, (ii)        
coverage with respect to Special Hazard Losses may be provided by one or more of
a Letter of Credit, Reserve Fund or a Special Hazard Insurance Policy (any      
instrument, to the extent providing such coverage, a 'Special Hazard            
Instrument'); (iii) coverage with respect to Bankruptcy Losses may be provided  
by one or more of a Letter of Credit, Reserve Fund or Bankruptcy Bond (any      
instrument, to the extent providing such coverage, a 'Bankruptcy Instrument')   
and (iv) coverage with respect to Fraud Losses may be provided by one or more of
a Letter of Credit, Reserve Fund or Fraud Bond (any instrument, to the extent   
providing such coverage, a 'Fraud Instrument'). In addition, if provided in the 
applicable Prospectus Supplement, in lieu of or in addition to any or all of the

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foregoing arrangements, credit enhancement may be in the form of subordination  
of one or more Classes of Certificates to provide credit support to one or more 
other Classes of Certificates. Credit support may also be provided in the form  
of an insurance policy covering the risk of collection and adequacy of any      
Additional Collateral provided in connection with any Additional Collateral     
Loan, subject to the limitations set forth in any such insurance policy.        

The amounts and types of credit enhancement arrangements as well as the 
provider thereof, if applicable, with respect to each Series of Certificates    
will be set forth in the related Prospectus Supplement. To the extent provided  
in the applicable Prospectus Supplement and the Pooling Agreement, the credit   
enhancement arrangements may be periodically modified, reduced and substituted  
for based on the aggregate outstanding principal balance of the Mortgage Loans  
covered thereby. If specified in the applicable Prospectus Supplement, credit   
support for a Series of Certificates may cover one or more other series of      
certificates issued by the Company or others.                                   

  Unless otherwise specified in the applicable Prospectus Supplement, to the
extent permitted by any applicable rating agency and provided that the then     
current ratings of the Certificates are maintained, coverage under any credit   
enhancement may be cancelled or reduced.                                        

The descriptions of any credit enhancement instruments included in this 
Prospectus or any Prospectus Supplement and the coverage thereunder do not      
purport to be complete and are qualified in their entirety by reference to the  
actual forms of governing documents, copies of which are available upon request.

MORTGAGE POOL INSURANCE                                                         

    A mortgage pool insurance policy (a 'Mortgage Pool Insurance Policy') may be
obtained for a particular Series of Certificates. Any such policy will be       
obtained by the Company or the Servicer, as applicable, from a Qualified Insurer
for the Mortgage Pool, covering loss by reason of the default in payments on any
Mortgage Loans included therein that are not covered as to their entire         
outstanding principal balances by Primary Insurance, FHA Insurance or VA        
Guarantees. Each Mortgage Pool Insurance Policy will cover all or a portion of  
those Mortgage Loans in a Mortgage Pool in an amount to be specified in the     
applicable Prospectus Supplement or in the related Current Report on Form 8-K.  
The term 'Mortgage Pool Insurance Policy' wherever used in this Prospectus or   
any Supplement shall refer to one or more such Mortgage Pool Insurance Policies 
as the context may require. The identity of the insurer or insurers and certain 
financial information with respect to the insurer or insurers for each Mortgage 
Pool will be contained in the applicable Prospectus Supplement or in the related
Current Report on Form 8-K. The Trust will be the named insured under any       
Mortgage Pool Insurance Policy. A Mortgage Pool Insurance Policy is not a       
blanket policy against loss, since claims thereunder may only be made respecting
particular defaulted Mortgage Loans and only upon the satisfaction of certain   
conditions precedent described below.                                           

    Any Mortgage Pool Insurance Policy will provide that no claim may be validly
presented thereunder unless (i) hazard insurance on the property securing the   
defaulted Mortgage Loan has been kept in force and real estate taxes and other  
protection and preservation expenses have been paid, (ii) if there has been     
physical loss or damage to the Mortgaged Property, it has been restored to its  
condition (reasonable wear and tear excepted) at the Cut-Off Date, (iii) any    
required Primary Insurance Policy is in effect for the defaulted Mortgage Loan  
and a claim thereunder has been submitted and settled, and (iv) the insured has 
acquired good and merchantable title to the Mortgaged Property free and clear of
liens except permitted encumbrances. Assuming the satisfaction of these         
conditions, the insurer will have the option to either (i) purchase the property
securing the defaulted Mortgage Loan at a price equal to the principal balance  
thereof, plus accrued and unpaid interest at the Mortgage Interest Rate to the  
date of purchase, less the amount of any loss paid under a Primary Insurance    
Policy, if any, or (ii) pay the difference between the proceeds received from an
approved sale of the property and the principal balance of the defaulted        
Mortgage Loan, plus accrued and unpaid interest at the Mortgage Interest Rate to
the date of payment of the claim, less the amount of such loss paid under a     
Primary Insurance Policy, if any. In each case, the insurer will reimburse the  
Master Servicer and the Seller/Servicer, or the Servicer with respect to Series 
of Certificates for which the Company will not act as Master Servicer, for      
certain expenses incurred by them.                                              

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An endorsement (an 'Advance Claims Endorsement') may be issued to any   
Mortgage Pool Insurance Policy which provides that the Insurer will make        
advances of monthly principal and interest payments on Mortgage Loans as to     
which the Seller/Servicer, or the Servicer with respect to Series of            
Certificates for which the Company will not act as Master Servicer, has not     
received a payment from the related Mortgagor and neither the Seller/Servicer   
nor the Master Servicer, or the Servicer, as applicable, has advanced such      
payment. The presence of such endorsement, if any, will be disclosed in the     
Prospectus Supplement.                                                          

An endorsement may also be issued to any Mortgage Pool Insurance Policy 
which provides that the insurer will pay claims presented under the Mortgage    
Pool Insurance Policy although claims made against the applicable Primary       
Insurance Policy have not been settled due to the insolvency, bankruptcy,       
receivership or assignment for the benefit of creditors of the issuer of the    
Primary Insurance Policy. The presence of such endorsement, if any, will be     
disclosed in the Prospectus Supplement.                                         

  Unless otherwise specified in the applicable Prospectus Supplement, to the
extent permitted by any applicable rating agency and provided that the then     
current ratings of the Certificates are maintained, coverage under any Mortgage 
Pool Insurance Policy may be cancelled or reduced.                              

The original amount of coverage under any Mortgage Pool Insurance Policy
will be reduced over the life of the Certificates by the aggregate dollar amount
of claims paid, less certain amounts realized by the insurer upon disposition of
foreclosed properties. The amount of claims paid includes certain expenses      
incurred by the Company or a Servicing Entity, as applicable, as Master         
Servicer, or the Servicer with respect to Series of Certificates for which there
will be no Master Servicer, as well as accrued interest on delinquent Mortgage  
Loans to the date of payment of the claim. Accordingly, if aggregate net claims 
paid under any Mortgage Pool Insurance Policy reach the original policy limit,  
coverage thereunder will lapse and any further losses will be borne by          
Certificateholders. In addition, in such event, the Company or a Servicing      
Entity, as applicable, as Master Servicer, or the Servicer, as applicable, will 
not be obligated (unless sufficient recoveries from other sources are expected) 
to make any further Advances, since such Advances would no longer be ultimately 
recoverable under the Mortgage Pool Insurance Policy. See 'Description of       
Certificates -- Advances'.                                                      

   Since the property subject to a defaulted Mortgage Loan must be restored to
its original condition prior to claiming against the insurer, no Mortgage Pool  
Insurance Policy will provide coverage against hazard losses. As set forth under
'Primary Insurance, FHA Mortgage Insurance, VA Mortgage Guaranty, Hazard        
Insurance; Claims Thereunder', the hazard insurance policies covering the       
Mortgage Loans typically exclude from coverage physical damage resulting from a 
number of causes, and even when the damage is covered, may afford recoveries    
which are significantly less than the full replacement of such losses. Further, 
any Special Hazard Insurance Policy which may be obtained does not cover all    
risks, and such coverage will be limited in amount. See ' -- Special Hazard     
Insurance' below. Certain hazard risks will, as a result, be uninsured against  
and will therefore be borne by Certificateholders.                              

A Mortgage Pool Insurance Policy may include a provision permitting the 
insurer to purchase defaulted Mortgage Loans from the Trust.                    

 See ' -- The Fraud Bond' below for a discussion of the possible effect of
fraudulent conduct or negligence by the Seller, the Seller/Servicer, the        
Servicer or the Mortgagor with respect to a Mortgage Loan on the coverage of a  
Mortgage Pool Insurance Policy.                                                 

SUBORDINATION                                                                   

   If so specified in the applicable Prospectus Supplement, distributions with
respect to scheduled principal, Principal Prepayments, interest or any          
combination thereof that otherwise would have been payable to one or more       
Classes of Certificates of a Series (the 'Subordinated Certificates') will      
instead be payable to holders of one or more other Classes of such Series (the  
'Senior Certificates') under the circumstances and to the extent specified in   
the Prospectus Supplement. If specified in the applicable Prospectus Supplement,
delays in receipt of scheduled payments on the Mortgage Loans and losses on     
defaulted Mortgage Loans will be borne first by the various Classes of          
Subordinated Certificates and thereafter by the various Classes of Senior       
Certificates, in each case under the circumstances and subject to the           
limitations specified in the Prospectus Supplement. The aggregate distributions 
in respect of                                                                   

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delinquent payments on the Mortgage Loans over the lives of the Certificates or 
at any time, the aggregate losses in respect of defaulted Mortgage Loans which  
must be borne by the Subordinated Certificates by virtue of subordination and   
the amount of the distributions otherwise distributable to the Subordinated     
Certificateholders that will be distributable to Senior Certificateholders on   
any Distribution Date may be limited as specified in the applicable Prospectus  
Supplement. If the aggregate distribution with respect to delinquent payments on
the Mortgage Loans or aggregate losses in respect of such Mortgage Loans were to
exceed the total amounts payable and available for distribution to holders of   
Subordinated Certificates or, if applicable, were to exceed the specified       
maximum amount, holders of Senior Certificates could experience losses on the   
Certificates.                                                                   

In addition to or in lieu of the foregoing, if so specified in the      
applicable Prospectus Supplement, all or any portion of distributions otherwise 
payable to holders of Subordinated Certificates on any Distribution Date may    
instead be deposited into one or more reserve accounts (the 'Reserve Account')  
established by the Trustee. If so specified in the applicable Prospectus        
Supplement, such deposits may be made on each Distribution Date, on each        
Distribution Date for specified periods or until the balance in the Reserve     
Account has reached a specified amount and, following payments from the Reserve 
Account to holders of Senior Certificates or otherwise, thereafter to the extent
necessary to restore the balance in the Reserve Account to required levels, in  
each case as specified in the Prospectus Supplement. If so specified in the     
applicable Prospectus Supplement, amounts on deposit in the Reserve Account may 
be released to the Company, a Servicing Entity, the Servicer or the Seller, as  
applicable, or the holders of any Class of Certificates at the times and under  
the circumstances specified in the Prospectus Supplement.                       

If specified in the applicable Prospectus Supplement, various Classes of
Senior Certificates and Subordinated Certificates may themselves be subordinate 
in their right to receive certain distributions to other Classes of Senior and  
Subordinated Certificates, respectively, through a cross support mechanism or   
otherwise.                                                                      

As between Classes of Senior Certificates and as between Classes of     
Subordinated Certificates, distributions may be allocated among such classes (i)
in the order of their scheduled final distribution dates, (ii) in accordance    
with a schedule or formula, (iii) in relation to the occurrence of events, or   
(iv) otherwise, in each case as specified in the applicable Prospectus          
Supplement. As between Classes of Subordinated Certificates, payments to holders
of Senior Certificates on account of delinquencies or losses and payments to any
Reserve Account will be allocated as specified in the Prospectus Supplement.    

THE FRAUD BOND                                                                  

    Some or all of the Primary Insurance Policies covering Mortgage Loans in any
Mortgage Pool may contain an exclusion from coverage for Fraud Losses. To       
provide limited protection to Certificateholders against losses in the event    
that coverage relating to a Mortgage Loan which otherwise would have been       
available under a Primary Insurance Policy is not ultimately available by reason
of such an exclusion, if so specified in the applicable Prospectus Supplement, a
Fraud Instrument may be obtained or established by the Company or the Servicer, 
as applicable, for the Mortgage Pool. The type, coverage amount and term of any 
such Fraud Instrument will be disclosed in the applicable Prospectus Supplement 
or in the related Current Report on Form 8-K, and the coverage amount may be    
cancelled or reduced during the life of the Mortgage Pool, provided that the    
then current ratings of the Certificates will not be adversely affected thereby.
The Company, a Servicing Entity or the Servicer, as applicable, may also replace
the initial Fraud Instrument with any other type of Fraud Instrument, provided  
that the then current ratings of the Certificates will not be adversely affected
thereby. The identity of the issuer of any Fraud Bond or the Letter of Credit   
providing such coverage and certain financial information with respect to such  
issuer will be contained in the applicable Prospectus Supplement or related     
Current Report on Form 8-K.                                                     

  In addition, the Company understands that, regardless of whether exclusion
language such as that described above is included in the insurance documents, it
is the policy of some or all issuers of Primary Insurance Policies and of       
Mortgage Pool Insurance Policies to deny coverage in circumstances involving    
fraudulent conduct or negligence by either the Seller, the Seller/Servicer, the 
Servicer or the Mortgagor. It is unclear whether any such denial would be upheld
by a court. Neither the repurchase obligation of the Company or the Servicing   
Entity, as applicable, with respect to Series of Certificates as to which the   
Company and/or a Servicing Entity will act as Master Servicer, or the Seller    
with respect to Series of                                                       

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Certificates as to which there will be no Master Servicer, nor any of the Fraud 
Instruments described above would apply to any such denial of coverage unless,  
as described above, such denial is based upon a specific exclusion relating to  
fraudulent conduct or negligence which is included in a Primary Insurance       
Policy.                                                                         

THE BANKRUPTCY BOND                                                             

 The Prospectus Supplement for certain Series may specify that the Company
and/or a Servicing Entity, as Master Servicer, or the Servicer with respect to  
Series of Certificates as to which there will be no Master Servicer, has        
undertaken to pay to the Trust for the benefit of Certificateholders any portion
of the principal balance of a Mortgage Loan which becomes unsecured pursuant to 
a proceeding under Chapter 7, 11 or 13 of the Federal Bankruptcy Code. If such  
obligation is undertaken, the Company and/or a Servicing Entity, as Master      
Servicer, or the Servicer, as applicable, will also agree to pay to the Trust   
for the benefit of Certificateholders any shortfall in payment of principal and 
interest resulting from the recasting of any originally scheduled monthly       
principal and interest payment pursuant to a ruling under the Bankruptcy Code.  
These payment obligations will be subject to the limitations specified in the   
applicable Pooling Agreement. The Company and/or Servicing Entity, as Master    
Servicer, or the Servicer, as applicable, will have the option, in lieu of      
making such payments, to repurchase any Mortgage Loan affected by bankruptcy    
court rulings. To insure the Company's or Servicing Entity's, as Master         
Servicer, or the Servicer's obligation to make the payments described above, the
Company and/or a Servicing Entity, as Master Servicer, or the Servicer, as      
applicable, will obtain or establish a Bankruptcy Instrument in an initial      
amount specified in the Prospectus Supplement or in the related Current Report  
on Form 8-K. The Prospectus Supplement or Current Report on Form 8-K may also   
specify that, provided that the then current ratings of the Certificates are    
maintained, coverage under any Bankruptcy Instrument may be cancelled or        
reduced. The Master Servicer with respect to Series of Certificates as to which 
the Company and/or a Servicing Entity will act as Master Servicer, or the       
Servicer with respect to Series of Certificates as to which there will be no    
Master Servicer, may also replace the initial method pursuant to which such     
coverage is provided with either of the other two alternative methods, provided 
that the then current ratings of the Certificates will not be adversely affected
thereby.                                                                        

SPECIAL HAZARD INSURANCE                                                        

   A Special Hazard Insurance Instrument may be established or obtained by the
Company, Servicing Entity or the Servicer, as applicable, for certain Series.   
Any Special Hazard Insurance Instrument will, subject to limitations described  
below, protect the holders of the Certificates evidencing such Mortgage Pool    
from (i) loss by reason of damage to properties subject to defaulted Mortgage   
Loans covered thereby caused by certain hazards (including earthquakes in some  
geographic areas, mud flows and floods) not insured against under customary     
standard forms of fire and hazard insurance policies with extended coverage, and
(ii) loss on such loans caused by reason of the application of the co-insurance 
clause typically contained in hazard insurance policies. The Company and/or a   
Servicing Entity, as Master Servicer, with respect to Series of Certificates as 
to which the Company and/or a Servicing Entity will act as Master Servicer, or  
the Servicer with respect to Series of Certificates as to which there will be no
Master Servicer, may also replace the initial method pursuant to which such     
coverage is provided with either of the other two alternative methods, provided 
that the then current ratings of the Certificates will not be adversely affected
thereby. The Prospectus Supplement or Current Report on Form 8-K may also       
specify that, provided the then current ratings of the Certificates are         
maintained, coverage under any Special Hazard Instrument may be cancelled or    
reduced. Any Special Hazard Insurance Policy will be issued by an insurance     
company licensed to transact a property and casualty insurance business in each 
state in which Mortgaged Properties covered thereby are located. The identity of
the issuer of any Special Hazard Insurance Policy or the Letter of Credit       
providing such coverage and certain financial information with respect to such  
issuer will be contained in the related Prospectus Supplement. No Special Hazard
Insurance Instrument will cover Extraordinary Losses.                           

Subject to the foregoing limitations, the terms of any Special Hazard   
Insurance Instrument will provide generally that, where there has been damage to
property securing a defaulted Mortgage Loan covered by such instrument and such 
damage is not fully covered by the hazard insurance policy                      

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maintained with respect to such property, the Special Hazard Insurance          
Instrument will pay either (i) the cost of repair of such property or (ii) the  
unpaid principal balance of such Mortgage Loan at the time of an approved sale  
of such property, plus accrued interest at the Mortgage Interest Rate to the    
date of claim settlement and certain expenses incurred in respect of such       
property, less any net proceeds upon the sale of such property. In either case, 
the amount paid under any Special Hazard Insurance Instrument will be reduced by
the proceeds, if any, received under the hazard insurance policy maintained with
respect to such property. It is expected that the Mortgage Pool Insurer, if any,
will represent to the Company and/or a Servicing Entity, as Master Servicer, or 
the Servicer, as applicable, that restoration of the property securing a        
Mortgage Loan from the proceeds described under (i) above will satisfy the      
condition under any related Mortgage Pool Insurance Policy that the property    
securing a defaulted Mortgage Loan be restored before a claim under any such    
policy may be validly presented in respect of such Mortgage Loan. The payment   
described under (ii) above will render unnecessary presentation of a claim in   
respect of such Mortgage Loan under any Mortgage Pool Insurance Policy.         
Therefore, so long as any Mortgage Pool Insurance Policy for a Series of        
Certificates remains in effect, the decision to pay the cost of repair rather   
than to pay the unpaid principal balance of the related Mortgage Loan, plus     
accrued interest and certain expenses, will not affect the amount of the total  
insurance proceeds paid to the holders of the Certificates of that Series with  
respect to such Mortgage Loan, but will affect the amount of special hazard     
insurance coverage remaining under any Special Hazard Insurance Instrument and  
the coverage remaining under any Mortgage Pool Insurance Policy obtained for    
that Series.                                                                    

LETTER OF CREDIT                                                                

  If any component of credit enhancement as to any Series of Certificates is
to be provided by a letter of credit (the 'Letter of Credit'), a bank or other  
entity (the 'Letter of Credit Bank') will deliver to the Trust an irrevocable   
Letter of Credit. The Letter of Credit Bank and certain information with respect
thereto, as well as the amount available under the Letter of Credit with respect
to each component of credit enhancement, will be specified in the applicable    
Prospectus Supplement. The Letter of Credit will expire on the expiration date  
set forth in the related Prospectus Supplement, unless earlier terminated or    
extended in accordance with its terms.                                          

   The Letter of Credit may also provide for the payment of Advances which the
Company or Servicing Entity, as applicable, as Master Servicer, with respect to 
Series of Certificates as to which the Company will act as Master Servicer, or  
the Servicer with respect to Series of Certificates as to which there will be no
Master Servicer, would be obligated to make with respect to delinquent monthly  
payments.                                                                       

RESERVE FUND                                                                    

If so specified in the related Prospectus Supplement, the Company, a    
Servicing Entity, the Servicer or the Seller, as applicable, will deposit or    
cause to be deposited in a reserve fund (a 'Reserve Fund') cash or Eligible     
Investments in specified amounts, or any other instruments satisfactory to the  
rating agency or agencies rating the Certificates offered pursuant to such      
Prospectus Supplement, which will be applied and maintained in the manner and   
under the conditions specified in such Prospectus Supplement. In the alternative
or in addition to such deposit, to the extent described in the related          
Prospectus Supplement, a Reserve Fund may be funded through application of all  
or a portion of amounts otherwise payable on one or more related Classes of     
Certificates, from Retained Yield, or otherwise. Amounts in a Reserve Fund may  
be used to provide one or more components of credit enhancement, or applied to  
reimburse the Company or Servicing Entity, as applicable, as Master Servicer,   
with respect to Series of Certificates as to which the Company and/or a         
Servicing Entity will act as Master Servicer, or the Servicer with respect to   
Series of Certificates as to which there will be no Master Servicer, for        
outstanding Advances, or may be used for other purposes, in the manner and to   
the extent specified in the related Prospectus Supplement. Unless otherwise     
provided in the related Prospectus Supplement, any such Reserve Fund will not be
deemed to be owned by the related Trust.                                        

  Amounts deposited in any Reserve Fund for a Series of Certificates will be
invested in Eligible Investments by, or at the direction of, and for the benefit
of the Company or Servicing Entity, as applicable, as Master Servicer, or the   
Certificate Administrator, as applicable, or any other person named in the      
related Prospectus Supplement. Unless otherwise specified in the applicable     
Prospectus Supplement,                                                          

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any amounts remaining in the Reserve Fund upon the termination of the Trust will
be returned to whomever deposited such amounts in the Reserve Fund.             

CERTIFICATE INSURANCE POLICIES                                                  

If so specified in the related Prospectus Supplement, the Company or the
Servicer may obtain one or more certificate insurance policies, issued by       
insurers acceptable to the rating agency or agencies rating the Certificates    
offered pursuant to such Prospectus Supplement, insuring the holders of one or  
more Classes of Certificates the payment of amounts due in accordance with the  
terms of such Class or Classes of Certificates, subject to such limitations and 
exceptions as are set forth in the applicable Prospectus Supplement.            

MAINTENANCE OF CREDIT ENHANCEMENTS; CLAIMS THEREUNDER                           
AND OTHER REALIZATION UPON DEFAULTED MORTGAGE LOANS                             

For each Series of Certificates which will be covered by a Mortgage Pool
Insurance Policy, or a Letter of Credit established in lieu of such policy (such
coverage to be disclosed in the applicable Prospectus Supplement), the Company  
and/or Servicing Entity, as Master Servicer, with respect to Series of          
Certificates as to which the Company will act as Master Servicer, or the        
Servicer with respect to Series of Certificates as to which there will be no    
Master Servicer, will exercise its best reasonable efforts to keep such Mortgage
Pool Insurance Policy or Letter of Credit in full force and effect throughout   
the term of the Pooling Agreement, unless coverage thereunder has been exhausted
through the payment of claims or until such instrument is replaced in accordance
with the terms of the Pooling Agreement. Unless otherwise specified in the      
applicable Prospectus Supplement, the Company and/or Servicing Entity, as Master
Servicer, or the Servicer, as applicable, will agree to pay the premiums for any
Mortgage Pool Insurance Policy, and the fee for any Letter of Credit, on a      
timely basis. In the event that the insurer under the Mortgage Pool Insurance   
Policy ceases to be a Qualified Insurer (as defined in the Pooling Agreement),  
or the Letter of Credit Bank ceases to be acceptable to the agency or agencies, 
if any, rating the Series, the Company or Servicing Entity, as applicable, as   
Master Servicer, or the Servicer, as applicable, will use its best reasonable   
efforts to obtain from another Qualified Insurer or letter of credit issuer a   
replacement policy or letter of credit comparable to the Mortgage Pool Insurance
Policy or Letter of Credit which it replaces, with total coverage equal to the  
then outstanding coverage of the Mortgage Pool Insurance Policy or Letter of    
Credit, provided that if the cost of the replacement policy or letter of credit 
is greater than the cost of the Mortgage Pool Insurance Policy or Letter of     
Credit being replaced, the coverage of the replacement policy or letter of      
credit for a Series of Certificates may be reduced to a level such that its     
premium rate or cost does not exceed 150% of the premium rate or cost of the    
Mortgage Pool Insurance Policy or Letter of Credit for a Series which is rated  
by one or more rating agencies, or 100% of the premium rate or cost for such    
policy or Letter of Credit for a Series which is not so rated.                  

    In addition, the Company and/or Servicing Entity, as Master Servicer, or the
Servicer, as applicable, may substitute at any time a Mortgage Pool Insurance   
Policy or Letter of Credit for an existing Mortgage Pool Insurance Policy or    
Letter of Credit. In no event, however, may the Company and/or Servicing Entity,
as Master Servicer, or the Servicer, as applicable, provide a Letter of Credit  
in lieu of a Mortgage Pool Insurance Policy, or vice-versa, or substitute one   
such instrument for another, except under the circumstances detailed in the     
preceding paragraph, if such action will impair the then current ratings, if    
any, of the Certificates.                                                       

Unless otherwise specified in the applicable Prospectus Supplement, each
Seller/Servicer with respect to Series of Certificates as to which the Company  
and/or a Servicing Entity will act as Master Servicer, or the Servicer with     
respect to Series of Certificates as to which there will be no Master Servicer, 
will cause a Primary Insurance Policy to be maintained in full force and effect 
with respect to each Mortgage Loan it services with a loan-to-value ratio in    
excess of 80%; provided, however, that if the loan-to-value ratio of a Mortgage 
Loan based on a subsequent appraisal of the Mortgaged Property is less than 80%,
such Primary Insurance Policy may be terminated, if so specified in the         
applicable Prospectus Supplement. Each Seller/Servicer or the Servicer, as      
applicable, will agree to pay the premium for each Primary Insurance Policy on a
timely basis in the event that the Mortgagor does not make such payments. See   

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'Primary Insurance, FHA Mortgage Insurance, VA Mortgage Guaranty, Hazard        
Insurance; Claims Thereunder -- Primary Insurance' herein.                      

 For each Series of Certificates which will be covered by a Special Hazard
Insurance Instrument (such coverage to be disclosed in the applicable Prospectus
Supplement), the Company and/or Servicing Entity, as Master Servicer with       
respect to Series of Certificates as to which the Company and/or a Servicing    
Entity will act as Master Servicer, or the Servicer with respect to Series of   
Certificates as to which there will be no Master Servicer, will exercise its    
best reasonable efforts to keep such Special Hazard Insurance Instrument in full
force and effect throughout the term of the Pooling Agreement, unless coverage  
thereunder has been exhausted through the payment of claims or until such       
Special Hazard Insurance Instrument has been replaced in accordance with the    
terms of the Pooling Agreement. So long as any applicable rating on a Series of 
Certificates will be maintained, the Company and/or Servicing Entity, as Master 
Servicer, or the Servicer, as applicable, may at any time replace the initial   
instrument providing special hazard coverage with either of the other two       
alternative methods. Unless otherwise specified in the applicable Prospectus    
Supplement, the Company or Servicing Entity, as Master Servicer, or the         
Servicer, as applicable, will agree to pay the premium for any Special Hazard   
Insurance Policy (or Letter of Credit obtained in lieu thereof) on a timely     
basis. Unless otherwise specified in the applicable Prospectus Supplement, any  
such policy will provide for a fixed premium rate on the declining balance of   
the Mortgage Loans. In the event that any Special Hazard Insurance Policy is    
cancelled or terminated for any reason other than the exhaustion of total policy
coverage, the Company, Servicing Entity or the Servicer, as applicable, is      
obligated either to substitute a Letter of Credit or Reserve Fund or to exercise
its best reasonable efforts to obtain from another insurer a replacement policy 
comparable to such Special Hazard Insurance Policy with a total coverage which  
is equal to the then existing coverage of such Special Hazard Insurance Policy; 
provided, however, that if the cost of any such replacement policy shall be     
greater than the cost of the original Special Hazard Insurance Policy, the      
amount of coverage of such replacement policy may be reduced to a level such    
that the cost shall be equal to the cost of the original Special Hazard         
Insurance Policy. As indicated above, in lieu of obtaining a replacement Special
Hazard Insurance Policy, the Company, Servicing Entity or the Servicer, as      
applicable, may obtain a Letter of Credit or establish a Reserve Fund in        
accordance with terms prescribed by any applicable rating agency so that any    
rating obtained for the Certificates will not be impaired.                      

   For each Series of Certificates which will be covered by a Fraud Instrument
(such coverage to be disclosed in the applicable Prospectus Supplement), the    
Company and/or a Servicing Entity, as Master Servicer, with respect to Series of
Certificates as to which the Company and/or a Servicing Entity will act as      
Master Servicer, or the Servicer with respect to Series of Certificates as to   
which there will be no Master Servicer, will exercise its best reasonable       
efforts to maintain and keep any such Fraud Instrument in full force and effect 
throughout the required term as set forth in the applicable Prospectus          
Supplement, unless coverage thereunder has been exhausted through the payment of
claims. The Company, Servicing Entity or the Servicer, as applicable, will agree
to pay the premium for any Fraud Bond or Bankruptcy Bond on a timely basis.     

For each Series of Certificates or Class of Certificates which will be  
covered by a certificate insurance policy or a Letter of Credit or Reserve Fund 
(such coverage to be disclosed in the applicable Prospectus Supplement), the    
Company and/or a Servicing Entity, as Master Servicer, with respect to Series of
Certificates as to which the Company will act as Master Servicer, or the        
Servicer with respect to Series of Certificates as to which there will be no    
Master Servicer, will exercise its best reasonable efforts to maintain and keep 
any such certificate insurance policy, Letter of Credit or Reserve Fund in full 
force and effect throughout the required term set forth in the applicable       
Prospectus Supplement. Unless otherwise specified in the Prospectus Supplement, 
the Company, Servicing Entity or the Servicer, as applicable, will agree to pay 
the premium for any certificate insurance policy on a timely basis.             

  The Company or Servicing Entity, as applicable, as Master Servicer, or the
Seller/Servicers, with respect to Series of Certificates as to which the Company
will act as Master Servicer, or the Servicer with respect to Series of          
Certificates as to which there will be no Master Servicer, on behalf of the     
Trust and Certificateholders, will present claims to the issuer of any          
applicable Primary Insurance Policy, FHA Insurance Policy, VA Guaranty, Mortgage
Pool Insurance Policy, Special Hazard Insurance Policy or Letter of Credit, or  
under any Reserve Fund or other form of credit enhancement, and will take such  
reasonable                                                                      

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steps as are necessary to permit recovery under such insurance policies or      
alternative coverages respecting defaulted Mortgage Loans. With respect to any  
applicable Fraud Bond, Bankruptcy Bond or certificate insurance policy, the     
Trustee will present claims to the issuer of such bond or policy on behalf of   
the Trust and the Certificateholders. As set forth above, all collections by the
Company or Servicing Entity, as applicable, as Master Servicer, or the          
Seller/Servicer, or the Servicer, as applicable, under such policies or         
alternative coverages that are not applied to the restoration of the related    
Mortgaged Property are to be deposited in the applicable Custodial Account for  
P&I, the Investment Account or the Certificate Account, subject to withdrawal as
heretofore described.                                                           

   If any property securing a defaulted Mortgage Loan is damaged and proceeds,
if any, from the related hazard insurance policy or any applicable Special      
Hazard Insurance Policy (or Letter of Credit or Reserve Fund), as the case may  
be, are insufficient to restore the damaged property to a condition sufficient  
to permit recovery under any applicable Mortgage Pool Insurance Policy or       
Primary Insurance Policy, the Company or Servicing Entity, as applicable, as    
Master Servicer, with respect to Series of Certificates as to which the Company 
and/or Servicing Entity will act as Master Servicer, or the Servicer with       
respect to Series of Certificates as to which there will be no Master Servicer, 
will not be required to expend its own funds to restore the damaged property    
unless it determines (i) that such restoration will increase the proceeds to    
Certificateholders upon liquidation of the Mortgage Loan after reimbursement of 
the Company, Servicing Entity or the Servicer, as applicable, for its expenses  
and (ii) that such expenses will be recoverable to it through Liquidation       
Proceeds or Insurance Proceeds.                                                 

 If recovery under any Mortgage Pool Insurance Policy (or Letter of Credit
established in lieu of such policy), Primary Insurance Policy, FHA Insurance    
Policy or VA Guaranty is not available because the Master Servicer, with respect
to Series of Certificates as to which the Company and/or a Servicing Entity will
act as Master Servicer, or the Servicer with respect to Series of Certificates  
as to which there will be no Master Servicer, has been unable to make the       
determinations described in the second preceding paragraph, or otherwise, the   
Seller/Servicer or the Servicer, as applicable, is, nevertheless, obligated to  
follow such normal practices and procedures as it deems necessary or advisable  
to realize upon the defaulted Mortgage Loan. If the proceeds of any liquidation 
of the property securing the defaulted Mortgage Loan are less than the principal
balance of the defaulted Mortgage Loan plus accrued and unpaid interest thereon 
at the applicable Pass-Through Rate (after deduction of the Retained Yield, if  
any, or a pro rata portion thereof as required by the applicable Pooling        
Agreement), Certificateholders in the aggregate will realize a loss in the      
amount of such difference plus the aggregate of expenses incurred by the Company
or Servicing Entity, as applicable, as Master Servicer, and the Seller/Servicer,
or the Servicer, as applicable, in connection with such proceedings and which   
are reimbursable under the Pooling Agreement. In addition, and as set forth     
above, in the event that the Company or Servicing Entity, as applicable, as     
Master Servicer, or the Servicer, as applicable, has expended its own funds to  
restore damaged property and such funds have not been reimbursed under any      
Special Hazard Insurance Policy or Letter of Credit or Reserve Fund, it will be 
entitled to receive from the Certificate Account, out of related Liquidation    
Proceeds or Insurance Proceeds, an amount equal to such expenses incurred by it,
in which event the Certificateholders may realize a loss up to the amount so    
charged. Since Insurance Proceeds cannot exceed deficiency claims and certain   
expenses incurred by the Company or Servicing Entity, as applicable, as Master  
Servicer, and the Seller/Servicers, or the Servicer, as applicable, no insurance
payments will result in a recovery to Certificateholders which exceeds the      
principal balance of the defaulted Mortgage Loan together with accrued and      
unpaid interest thereon at the applicable Pass-Through Rate. In addition, where 
property securing a defaulted Mortgage Loan can be resold for an amount         
exceeding the principal balance of any related Mortgage Note together with      
accrued interest and expenses, it may be expected that, where retention of any  
such amount is legally permissible, the insurer will exercise its right under   
any related Mortgage Pool Insurance Policy to purchase such property and realize
for itself any excess proceeds. In addition, with respect to certain Series of  
Certificates, if so provided in the applicable Prospectus Supplement, the       
Company or Servicing Entity, as applicable, as Master Servicer, or the Servicer,
as applicable, may have the option to purchase from the Trust any defaulted     
Mortgage Loan after a specified period of delinquency. If a defaulted Mortgage  
Loan is not so removed from the Trust, then, upon the final liquidation thereof,
if a loss is realized which is not covered by any applicable form of credit     
enhancement or other insurance, the Certificateholders will bear such loss.     
However, if a gain results from the final liquidation of a defaulted Mortgage   
Loan which is not required by law to be                                         

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remitted to the related Mortgagor, the Company or Servicing Entity, as          
applicable, as Master Servicer, or the Servicer, as applicable, will be entitled
to retain such gain as additional servicing compensation unless the applicable  
Prospectus Supplement provides otherwise. See 'Description of Credit            
Enhancements'.                                                                  

CERTAIN LEGAL ASPECTS OF THE MORTGAGE LOANS 

The Mortgages (other than the security agreements with respect to the   
Cooperative Loans) will be either deeds of trust or mortgages, depending upon   
the prevailing practice in the state in which the Mortgaged Property is located.
A mortgage creates a lien upon the real property encumbered by the mortgage. It 
is not prior to the lien for real estate taxes and assessments. Priority between
mortgages depends on their terms and generally on the order of filing with a    
state or county office. There are two parties to a mortgage: the mortgagor, who 
is usually the borrower and homeowner, and the mortgagee, who is the lender.    
Under the mortgage instrument, the mortgagor delivers to the mortgagee a note or
bond and the mortgage. Although a deed of trust is similar to a mortgage, a deed
of trust formally has three parties; the borrower-homeowner, called the trustor 
(similar to a mortgagor), a lender, called the beneficiary (similar to a        
mortgagee), and a third-party grantee, called the trustee. Under a deed of      
trust, the trustor grants the property, irrevocably until the debt is paid, in  
trust, generally with a power of sale, to the trustee to secure payment of the  
obligation. In some cases, a mortgage will also contain a power of sale. The    
trustee's authority under a deed of trust and the mortgagee's authority under a 
mortgage are governed by law, by the express provisions of the deed of trust or 
mortgage and, in some cases, by the directions of the beneficiary. For purposes 
of the following discussion, 'mortgagor' shall, as appropriate, refer to a      
mortgagor or trustor and 'lender' shall refer to a mortgagee or beneficiary. A  
Mortgage Pool may also contain Cooperative Loans which are described below under
' -- Cooperative Loans'.                                                        

COOPERATIVE LOANS                                                               

If specified in the Prospectus Supplement relating to a Series of       
Certificates, the Mortgage Loans may also include Cooperative Loans. Each       
promissory note (a 'Cooperative Note') evidencing a Cooperative Loan will be    
secured by a security interest in shares issued by the related private          
cooperative housing corporation (a 'Cooperative') that owns the related         
apartment building, which is a corporation entitled to be treated as a housing  
cooperative under federal tax law, and in the related proprietary lease or      
occupancy agreement granting exclusive rights to occupy a specific dwelling unit
in the Cooperative's building. The security agreement will create a lien upon or
grant a security interest in the cooperative shares and proprietary lease or    
occupancy agreement, the priority of which will depend on the terms of the      
particular security agreement as well as the order of recordation of the        
agreement (or the filing of the financing statements related thereto) in the    
appropriate recording office or the taking of possession of the cooperative     
shares, depending on the law of the state in which the Cooperative is located.  
Such a lien or security interest is not, in general, prior to liens in favor of 
the Cooperative for unpaid assessments or common charges.                       

Unless otherwise specified in the related Prospectus Supplement, all    
cooperative buildings relating to the Cooperative Loans are located in the      
States of New York and New Jersey. Generally, each Cooperative owns in fee or   
has a leasehold interest in all the real property and owns in fee or leases the 
building and all separate dwelling units therein. The Cooperative is directly   
responsible for property management and, in most cases, payment of real estate  
taxes, other governmental impositions and hazard and liability insurance. If    
there is an underlying mortgage (or mortgages) on the Cooperative's building or 
underlying land, as is generally the case, or an underlying lease of the land,  
as is the case in some instances, the Cooperative, as mortgagor or lessee, as   
the case may be, is also responsible for fulfilling such mortgage or rental     
obligations. An underlying mortgage loan is ordinarily obtained by the          
Cooperative in connection with either the construction or purchase of the       
Cooperative's building or the obtaining of capital by the Cooperative. The      
interest of the occupant under proprietary leases or occupancy agreements as to 
which that Cooperative is the landlord are generally subordinate to the interest
of the holder of an underlying mortgage and to the interest of the holder of a  
land lease. If the Cooperative is unable to meet the payment obligations (i)    
arising under an underlying mortgage, the mortgagee holding an underlying       
mortgage could foreclose on that mortgage and terminate all subordinate         
proprietary leases and occupancy agreements or (ii) arising under its land      
lease, the holder of the landlord's interest under the land lease               

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could terminate it and all subordinate proprietary leases and occupancy         
agreements. In addition, an underlying mortgage on a Cooperative may provide    
financing in the form of a mortgage that does not fully amortize, with a        
significant portion of principal being due in one final payment at maturity. The
inability of the Cooperative to refinance a mortgage and its consequent         
inability to make such final payment could lead to foreclosure by the mortgagee.
Similarly, a land lease has an expiration date and the inability of the         
Cooperative to extend its term or, in the alternative, to purchase the land,    
could lead to termination of the Cooperative's interest in the property and     
termination of all proprietary leases and occupancy agreements. In either event,
a foreclosure by the holder of an underlying mortgage or the termination of the 
underlying lease could eliminate or significantly diminish the value of any     
collateral held by the lender who financed the purchase by an individual        
tenant-stockholder of shares of the Cooperative or, in the case of a Mortgage   
Pool, the collateral securing any related Cooperative Loans.                    

Each Cooperative is owned by shareholders (referred to as               
tenant-stockholders) who, through ownership of stock or shares in the           
Cooperative, receive proprietary leases or occupancy agreements which confer    
exclusive rights to occupy specific dwellings. Generally, a tenant-stockholder  
of a Cooperative must make a monthly maintenance payment to the Cooperative     
pursuant to the proprietary lease, which maintenance payment represents such    
tenant-stockholder's pro rata share of the Cooperative's payments for its       
underlying mortgage, real property taxes, maintenance expenses and other capital
or ordinary expenses. An ownership interest in a Cooperative and accompanying   
occupancy rights may be financed through a Cooperative Loan evidenced by a      
Cooperative Note and secured by an assignment of and a security interest in the 
occupancy agreement or proprietary lease and a security interest in the shares  
of the related Cooperative. The lender generally takes possession of the share  
certificate and a counterpart of the proprietary lease or occupancy agreement   
and a financing statement covering the proprietary lease or occupancy agreement 
and the Cooperative shares is filed in the appropriate state and local offices  
to perfect the lender's interest in its collateral. Subject to the limitations  
discussed below, upon default of the tenant-stockholder, the lender may sue for 
judgment on the Cooperative Note, dispose of the collateral at a public or      
private sale or otherwise proceed against the collateral or tenant-stockholder  
as an individual as provided in the security agreement covering the assignment  
of the proprietary lease or occupancy agreement and the pledge of Cooperative   
shares. See ' -- Foreclosure on Shares of Cooperatives' below.                  

TAX ASPECTS OF COOPERATIVE OWNERSHIP                                            

  In general, a 'tenant-stockholder' (as defined in Section 216(b)(2) of the
Code) of a corporation that qualifies as a 'cooperative housing corporation'    
within the meaning of Section 216(b)(1) of the Code is allowed a deduction under
Section 216(a) of the Code for amounts paid or accrued within his or her taxable
year to the corporation representing his or her proportionate share of certain  
interest expenses and certain real estate taxes allowable as deductions to the  
corporation under Sections 163 and 164 of the Code. In order for a corporation  
to qualify under Section 216(b)(1) of the Code for the taxable year to which    
such interest and tax deductions relate, such section requires, among other     
things, that at least 80% of the gross income of the corporation be derived from
its tenant-stockholders. By virtue of this requirement, the status of a         
corporation for purposes of Section 216(b)(1) of the Code must be determined on 
a year-to-year basis. Consequently, there can be no assurance that Cooperatives 
relating to the Cooperative Loans will qualify under such section for any       
particular year. In the event that such a Cooperative fails to qualify for one  
or more years, the value of the collateral securing any related Cooperative     
Loans could be significantly impaired because no deduction would be allowable to
tenant-stockholders under Section 216(a) of the Code with respect to those      
years. In view of the significance of the tax benefits accorded                 
tenant-stockholders of a corporation that qualifies under Section 216(b)(1) of  
the Code, the likelihood that such a failure would be permitted to continue over
a period of years appears remote.                                               

FORECLOSURE                                                                     

   Foreclosure may be accomplished by judicial action. The action is initiated
by the service of legal pleadings upon all parties having an interest in the    
real property. Delays in completion of the foreclosure may occasionally result  
from difficulties in locating necessary parties defendant. Judicial foreclosure 
proceedings are generally not contested by any of the parties defendant.        
However, when the lender's right                                                

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to foreclose is contested, the legal proceedings necessary to resolve the issue 
can be time consuming. After the completion of judicial foreclosure, the court  
would issue a judgment of foreclosure and would generally appoint a referee or  
other court officer to conduct the sale of property.                            

In many states, foreclosure of a mortgage or deed of trust may also be  
accomplished by a nonjudicial sale under a specific provision in the mortgage or
deed of trust which authorizes the sale of the property at public auction upon  
default by the mortgagor. The laws of the various states establish certain      
notice requirements for non-judicial foreclosure sales. In some states, notice  
of default must be recorded and sent to the mortgagor and to any person who has 
recorded a request for a copy of a notice of default and notice of sale. In     
addition, notice must be provided in some states to certain other persons       
including junior lienholders and any other individual having an interest in the 
real property. In some states, the mortgagor, or any other person having a      
junior encumbrance on the real estate, may, during a reinstatement period, cure 
the default by paying the entire amount in arrears, plus the costs and expenses 
incurred in enforcing the obligation. Generally, state law controls the amount  
of foreclosure expenses and costs, including limited attorneys' fees, which may 
be recovered by a lender. Some states also require a notice of sale to be posted
in a public place and published for a specified period of time in one or more   
newspapers. In addition, some state laws require that a copy of the notice of   
sale be posted on the property and sent to all parties having an interest in the
real property.                                                                  

   In case of foreclosure under either a mortgage or a deed of trust, the sale
by the receiver or other designated officer or by the trustee is a public sale. 
However, because of a number of factors, including the difficulty a potential   
buyer at the sale would have in determining the exact status of title and the   
fact that the physical condition of the property may have deteriorated during   
the foreclosure proceedings, it is uncommon for a third party to purchase the   
property at the foreclosure sale. Rather, it is common for the lender to        
purchase the property from the trustee or referee with a credit bid in an amount
equal to the principal amount of the mortgage or deed of trust, accrued and     
unpaid interest and the expenses of foreclosure. Thereafter, the lender will    
assume the burdens of ownership, including obtaining casualty insurance and     
making such repairs at its own expense as are necessary to render the property  
suitable for sale. The lender will commonly obtain the services of a real estate
broker and pay the broker's commission in connection with the sale of the       
property. Depending upon market conditions, the ultimate proceeds of the sale of
the property may not equal the lender's investment in the property.             

Courts have imposed general equitable principles upon foreclosure       
proceedings. These equitable principles are generally designed to relieve the   
mortgagor from the legal effect of his defaults under the loan documents.       
Examples of judicial remedies that have been fashioned include judicial         
requirements that the lender undertake affirmative and sometimes expensive      
actions to determine the causes for the mortgagor's default and the likelihood  
that the mortgagor will be able to reinstate the loan. In some cases, courts    
have substituted their judgment for the lender's judgment and have required that
lenders reinstate loans or recast payment schedules in order to accommodate     
mortgagors who are suffering from a temporary financial disability. In other    
cases, courts have limited the right of the lender to foreclose if the default  
under the security instrument is not monetary, such as the mortgagor failing to 
adequately maintain or insure the property or the mortgagor executing a second  
mortgage or deed of trust affecting the property. Some courts have been faced   
with the issue of whether or not federal or state constitutional provisions     
reflecting due process concerns for adequate notice require that mortgagors     
receive notices in addition to the statutorily prescribed minimum. For the most 
part, these cases have upheld the notice provisions as being reasonable or have 
found that the foreclosure sale does not involve sufficient state action to     
afford constitutional protections to the mortgagor.                             

FORECLOSURE ON SHARES OF COOPERATIVES                                           

 The Cooperative shares owned by the tenant-stockholder, together with the
rights of the tenant-stockholder under the proprietary lease or occupancy       
agreement, are pledged to the lender and are, in almost all cases, subject to   
restrictions on transfer as set forth in the Cooperative's certificate of       
incorporation and by-laws, as well as in the proprietary lease or occupancy     
agreement. The proprietary lease or occupancy agreement, even while pledged, may
be cancelled by the Cooperative for failure by the tenant-stockholder to pay    
maintenance or other obligations or charges owed by such tenant-stockholder,    
including mechanics' liens against the Cooperative's building incurred by such  
tenant-stockholder.                                                             

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Generally, maintenance and other obligations and charges arising under a        
proprietary lease or occupancy agreement which are owed to the Cooperative are  
made liens upon the shares to which the proprietary lease or occupancy agreement
relates. In addition, the proprietary lease or occupancy agreement generally    
permits the Cooperative to terminate such lease or agreement in the event the   
borrower defaults in the performance of covenants thereunder. Typically, the    
lender and the Cooperative enter into a recognition agreement which, together   
with any lender protection provisions contained in the proprietary lease,       
establishes the rights and obligations of both parties in the event of a default
by the tenant-stockholder on its obligations under the proprietary lease or     
occupancy agreement. A default by the tenant-stockholder under the proprietary  
lease or occupancy agreement will usually constitute a default under the        
security agreement between the lender and the tenant-stockholder.               

The recognition agreement generally provides that, in the event that the
tenant-stockholder has defaulted under the proprietary lease or occupancy       
agreement, the Cooperative will take no action to terminate such lease or       
agreement until the lender has been provided with notice of and an opportunity  
to cure the default. The recognition agreement typically provides that if the   
proprietary lease or occupancy agreement is terminated, the Cooperative will    
recognize the lender's lien against proceeds from a sale of the shares and the  
proprietary lease or occupancy agreement allocated to the dwelling, subject,    
however, to the Cooperative's right to sums due under such proprietary lease or 
occupancy agreement or which have become liens on the shares relating to the    
proprietary lease or occupancy agreement. The total amount owed to the          
Cooperative by the tenant-stockholder, which the lender generally cannot        
restrict and does not monitor, could reduce the amount realized upon a sale of  
the collateral below the outstanding principal balance of the Cooperative Loan  
and accrued and unpaid interest thereon.                                        

  Recognition agreements also generally provide that in the event the lender
succeeds to the tenant-stockholder's shares and proprietary lease or occupancy  
agreement as the result of realizing upon its collateral for a Cooperative Loan,
the lender must obtain the approval or consent of the board of directors of the 
Cooperative as required by the proprietary lease before transferring the        
Cooperative shares and assigning the proprietary lease. Such approval or consent
is usually based on the prospective purchaser's income and net worth, among     
other factors, and may significantly reduce the number of potential purchasers, 
which could limit the ability of the lender to sell and realize upon the value  
of the collateral. Generally, the lender is not limited in any rights it may    
have to dispossess the tenant-stockholder.                                      

Because of the nature of Cooperative Loans, lenders do not require the  
tenant-stockholder (i.e., the borrower) to obtain title insurance of any type.  
Consequently, the existence of any prior liens or other imperfections of title  
affecting the Cooperative's building or real estate also may adversely affect   
the marketability of the shares allocated to the dwelling unit in the event of  
foreclosure.                                                                    

 A foreclosure on the Cooperative shares is accomplished by public sale in
accordance with the provisions of Article 9 of the Uniform Commercial Code (the 
'UCC') and the security agreement relating to those shares. Article 9 of the UCC
requires that a sale be conducted in a 'commercially reasonable' manner. Whether
a sale has been conducted in a 'commercially reasonable' manner will depend on  
the facts in each case. In determining commercial reasonableness, a court will  
look to the notice given the debtor and the method, manner, time, place and     
terms of the sale and the sale price. Generally, a sale conducted according to  
the usual practice of creditors selling similar collateral will be considered   
reasonably conducted.                                                           

   Article 9 of the UCC provides that the proceeds of the sale will be applied
first to pay the costs and expenses of the sale and then to satisfy the         
indebtedness secured by the lender's security interest. The recognition         
agreement, however, generally provides that the lender's right to reimbursement 
is subject to the right of the Cooperative corporation to receive sums due under
the proprietary lease or occupancy agreement. If there are proceeds remaining,  
the lender must account to the tenant-stockholder for the surplus. Conversely,  
if a portion of the indebtedness remains unpaid, the tenant-stockholder is      
generally responsible for the deficiency. See ' -- Anti-Deficiency Legislation  
and Other Limitations on Lenders' below.                                        

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RIGHTS OF REDEMPTION                                                            

    In some states, after sale pursuant to a deed of trust or foreclosure of the
mortgage, there are statutory periods during which the mortgagor and foreclosed 
junior lienors may redeem the property from the foreclosure sale. One effect of 
the statutory right of redemption is to diminish the ability of the lender to   
sell the foreclosed property because the right of redemption would defeat the   
title of any purchaser from the lender subsequent to foreclosure or sale under a
deed of trust. As a practical matter, the lender may therefore be forced to     
retain the property and pay the expenses of ownership until the redemption      
period has run.                                                                 

ANTI-DEFICIENCY LEGISLATION AND OTHER LIMITATIONS ON LENDERS                    

Certain states have imposed statutory prohibitions which restrict or    
eliminate the remedies of a lender under a deed of trust or a mortgage. In some 
states, statutes limit the right of the lender to obtain a deficiency judgment  
against the mortgagor following sale under a deed of trust or foreclosure. A    
deficiency judgment would be a personal judgment against the former mortgagor   
equal in most cases to the difference between the net amount realized upon the  
public sale of the real property and the amount due to the lender. Other        
statutes may require the lender to exhaust the security afforded under a deed of
trust or mortgage by foreclosure in an attempt to satisfy the full debt before  
bringing a personal action against the mortgagor. Some state statutes also      
prohibit any deficiency judgment where the loan proceeds were used to purchase  
an owner-occupied dwelling. Finally, other statutory provisions limit any       
deficiency judgment against the former mortgagor following a judicial sale to   
the excess of the outstanding debt over the fair market value of the property at
the time of the public sale. The basic purpose of these statutes is to prevent a
lender from obtaining a large deficiency judgment against the former mortgagor  
as a result of low or no bids at the judicial sale.                             

 Generally, Article 9 of the UCC governs foreclosure on Cooperative shares
and the related proprietary lease or occupancy agreement. Some courts have      
interpreted Article 9 to prohibit or limit a deficiency award in certain        
circumstances, including circumstances where the disposition of the collateral  
(which, in the case of a Cooperative Loan, would be the shares of the           
Cooperative and the related proprietary lease or occupancy agreement) was not   
conducted in a commercially reasonable manner. With respect to mortgage loans   
secured by collateral in addition to the related real properties, realization   
upon the additional collateral may be governed by the UCC in effect under the   
law of the state applicable thereto. Some courts have interpreted the UCC to    
prohibit or limit a deficiency award in certain circumstances, including those  
in which the disposition of the collateral was not conducted in a commercially  
reasonable manner. In some states, the UCC does not apply to liens upon         
additional collateral consisting of certain types of personal property          
(including, for example, bank accounts and, to a certain extent, insurance      
policies and annuities). Realization upon such additional collateral will be    
governed by state laws other than the UCC, and the availability of deficiency   
awards under such state laws may be limited. Whether realization upon any       
Additional Collateral is governed by the UCC or by other state laws, the ability
of secured parties to realize upon the additional collateral may be limited by  
statutory prohibitions that limit remedies in respect of the related mortgage   
loans. Such prohibitions may affect secured parties either independently or in  
conjunction with statutory requirements that secured parties proceed against the
related mortgaged real properties first or against both such mortgaged real     
properties and the additional collateral concurrently. Some state statutes      
require secured parties to exhaust the security afforded by the mortgaged real  
properties through foreclosure before attempting to realize upon the related    
additional collateral (including any third-party guarantees). Other state       
statutes require secured parties to foreclose upon mortgaged real properties and
additional collateral concurrently. In states where statutes limit the rights of
secured parties to obtain deficiency judgments against borrowers or guarantors  
following foreclosure upon the related real mortgaged properties and where      
secured parties either are required or elect to proceed against such mortgaged  
real properties before proceeding against the related additional collateral,    
limitations upon the amounts of deficiency judgments may reduce the amounts that
may be realized by the secured parties upon the disposition of such additional  
collateral. Further, in certain states where secured parties may choose whether 
to proceed against the related mortgaged real properties or additional          
collateral first or against both concurrently, the secured parties, following a 
proceeding against one, may be deemed to have elected a remedy and may be       
precluded from thereafter exercising remedies with respect to the               

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other and resulting in a loss of its lien to such other collateral.             
Consequently, the practical effect of the election requirement, in those states 
permitting such election, is that secured parties will usually proceed against  
both concurrently or against the mortgaged real properties first if prohibited  
from proceeding against both by state law.                                      

In addition to anti-deficiency and related legislation, numerous other  
statutory provisions, including the federal bankruptcy laws and state laws      
affording relief to debtors, may interfere with or affect the ability of the    
secured mortgage lender to collect the full amount of interest due or realize   
upon its security. For example, with respect to federal bankruptcy law, a court 
with federal bankruptcy jurisdiction may permit a mortgagor through his or her  
Chapter 11, Chapter 12 or Chapter 13 rehabilitative plan to cure a monetary     
default in respect of a mortgage loan on the mortgagor's residence by paying    
arrearages within a reasonable time period and reinstating the original mortgage
loan payment schedule even though the lender accelerated the mortgage loan and  
foreclosure proceedings had occurred prior to the filing of the debtor's        
petition. Some courts with federal bankruptcy jurisdiction have approved plans, 
based on the particular facts of the reorganization case, that effected the     
curing of a mortgage loan default by paying arrearages over a number of years.  

    Courts with federal bankruptcy jurisdiction have also held that the terms of
a mortgage loan secured by property of the mortgagor may be modified. These     
courts have held that such modifications may include reducing the amount of each
monthly payment, changing the rate of interest, altering the repayment schedule,
and reducing the lender's security interest to the value of the residence, thus 
leaving the lender in the position of a general unsecured creditor for the      
difference between the value of the residence and the outstanding balance of the
loan. Courts with federal bankruptcy jurisdiction similarly may be able to      
modify the terms of a Cooperative Loan.                                         

The Code provides priority to certain tax liens over the lien of the    
security instrument. Numerous federal and some state consumer protection laws   
impose substantive requirements upon lenders in connection with the origination 
and the servicing of mortgage loans. These laws include the federal Truth-      
in-Lending Act, Real Estate Settlement Procedures Act, Equal Credit Opportunity 
Act, Fair Credit Billing Act, Fair Credit Reporting Act and related statutes.   
These federal laws impose specific statutory liabilities upon lenders who       
originate mortgage loans and who fail to comply with the provisions of the law. 
In some cases, this liability may affect assignees of the mortgage loans.       

ENFORCEABILITY OF CERTAIN PROVISIONS                                            

The standard forms of note, mortgage and deed of trust used by lenders  
generally contain 'due-on-sale' clauses. These clauses permit the lender to     
accelerate the maturity of the loan if the mortgagor sells, transfers or conveys
the property. The enforceability of these clauses was the subject of legislation
and litigation in many states, and in some cases the enforceability of these    
clauses was limited or denied. However, the Garn-St Germain Depository          
Institutions Act of 1982 (the 'Garn-St Germain Act') purports to pre-empt state 
statutory and case law that prohibits the enforcement of 'due-on-sale' clauses  
and permits lenders to enforce these clauses in accordance with their terms,    
subject to certain limited exceptions. The Garn-St Germain Act does 'encourage' 
lenders to permit assumption of loans at the original rate of interest or at    
some other rate less than the average of the original rate and the market rate. 
In addition, certain states have continuing restrictions on the enforceability  
of due-on-sale clauses for certain loans.                                       

  The Garn-St Germain Act also sets forth nine specific instances in which a
mortgage lender covered by the act (including federal savings associations and  
federal savings banks) may not exercise a 'due-on-sale' clause, notwithstanding 
the fact that a transfer of the property may have occurred. These include       
intrafamily transfers, certain transfers by operation of law, leases of less    
than three years and the creation of a junior encumbrance. Regulations          
promulgated under the Garn-St Germain Act by the Federal Home Loan Bank Board   
(now the Office of Thrift Supervision) and statutes in some states also prohibit
the imposition of a prepayment penalty upon the acceleration of a loan pursuant 
to a 'due-on-sale' clause. In addition, a few states have exercised their rights
under the Garn-St Germain Act to limit the enforceability of the due-on-sale    
clauses in certain loans made prior to passage of the Garn-St Germain Act. As of
the date hereof, certain states have taken action to reimpose interest rate     
limits and/or to limit discount points or other charges.                        

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    A consequence of the inability to enforce a due-on-sale clause may be that a
mortgagor's buyer may assume the existing mortgage loan rather than paying it   
off, if such existing loan bears an interest rate below the current market rate,
which may have an impact upon the average life of the Mortgage Loans and the    
number of Mortgage Loans which may be outstanding until maturity.               

  Under the terms of the Servicemembers Civil Relief Act (the 'Relief Act'),
formerly known as the Soldiers' and Sailors' Civil Relief Act of 1940, a        
Mortgagor who enters military service after the origination of such Mortgagor's 
Mortgage Loan (including a Mortgagor who is a member of the National Guard or is
in reserve status at the time of the origination of the Mortgage Loan and is    
later called to active duty) may not be charged interest above an annual rate of
6% during the period of such Mortgagor's active duty status, and the lender must
forgive any interest above such annual rate, unless a court or administrative   
agency of the United States or of any State orders otherwise upon application of
the lender. Any shortfall in interest collections resulting from the application
of the Relief Act, to the extent not covered by any applicable credit           
enhancements, could result in losses to the Holders of the Certificates. In     
addition, the Relief Act imposes limitations which would impair the ability of  
the Servicer to foreclose on an affected Mortgage Loan during the Mortgagor's   
period of active duty status. Thus, in the event that such a Mortgage Loan goes 
into default, there may be delays and losses occasioned by the inability to     
realize upon the Mortgaged Property in a timely fashion.                        

APPLICABILITY OF USURY LAWS                                                     

    Title V of the Depository Institutions Deregulation and Monetary Control Act
of 1980, enacted in March 1980 ('Title V'), provides that state usury           
limitations shall not apply to certain types of residential first mortgage loans
originated by certain lenders after March 31, 1980. A similar federal statute   
was in effect with respect to mortgage loans made during the first three months 
of 1980. The Federal Home Loan Bank Board (now the Office of Thrift Supervision)
has issued regulations governing the implementation of Title V. The statute     
authorizes any state to reimpose interest rate limits by adopting before April  
1, 1983, a law or constitutional provision which expressly rejects application  
of the federal law. In addition, even where Title V is not so rejected, any     
state is authorized to adopt a provision limiting discount points or other      
charges prior to origination on mortgage loans covered by Title V.              

 Under the Company's mortgage purchase program, each Lender is required to
represent and warrant to the Company that all Mortgage Loans are originated in  
full compliance with applicable state laws, including usury laws. Based upon    
such representations and warranties from the Lenders, the Company will make a   
similar representation and warranty in the Pooling Agreement for each Series to 
the Trust. See 'Description of Certificates -- Representations and Warranties'. 

ALTERNATIVE MORTGAGE INSTRUMENTS                                                

   Alternative mortgage instruments, including adjustable-rate mortgage loans,
originated by non-federally chartered lenders have historically been subjected  
to a variety of restrictions. Such restrictions differed from state to state,   
resulting in difficulties in determining whether a particular alternative       
mortgage instrument originated by a state-chartered lender was in compliance    
with applicable law. These difficulties were alleviated substantially as a      
result of the enactment of Title VIII of the Garn-St Germain Act ('Title VIII').
Title VIII provides that, notwithstanding any state law to the contrary,        
state-chartered banks may originate alternative mortgage instruments in         
accordance with regulations promulgated by the Comptroller of the Currency with 
respect to origination of alternative mortgage instruments by national banks,   
state-chartered credit unions may originate alternative mortgage instruments in 
accordance with regulations promulgated by the National Credit Union            
Administration with respect to origination of alternative mortgage instruments  
by federal credit unions, and all other non-federally chartered housing         
creditors, including state-chartered savings and loan associations,             
state-chartered savings banks and mortgage banking companies, may originate     
alternative mortgage instruments in accordance with the regulations promulgated 
by the Federal Home Loan Bank Board (now the Office of Thrift Supervision) with 
respect to origination of alternative mortgage instruments by federal savings   
and loan associations. Title VIII provides that any state may reject            
applicability of the provisions of Title VIII by adopting, prior to October 15, 
1985, a law or constitutional provision expressly rejecting the applicability of
such provisions. Certain states have taken such action.                         

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ENVIRONMENTAL RISKS                                                             

  Real property pledged as security to a lender may be subject to unforeseen
environmental risks. Under the laws of certain states, contamination of a       
property may give rise to a lien on the property to assure the payment of costs 
of clean-up. In several states such a lien has priority over the lien of an     
existing mortgage against such property.                                        

In addition, under the laws of some states and under the federal        
Comprehensive Environmental Response, Compensation and Liability Act of 1980    
('CERCLA'), a lender may be liable, as an 'owner' or 'operator', for costs      
arising out of releases or threatened releases of hazardous substances that     
require remedy at a mortgaged property. CERCLA imposes liability for such costs 
on any and all 'responsible parties', including the current owner or operator of
a contaminated property, regardless of whether or not the environmental damage  
was caused by a prior owner. However, CERCLA excludes from the definition of    
'owner or operator' a secured creditor who holds indicia of ownership primarily 
to protect its security interest, but does not 'participate in the management'  
of a mortgaged property. The conduct which constitutes 'participation in the    
management', such that the lender would lose the protection of the exclusion for
secured creditors, has been a matter of judicial interpretation of the statutory
language, and court decisions have historically been inconsistent. In 1990, the 
United States Court of Appeals for the Eleventh Circuit suggested, in United    
States v. Fleet Factors Corp., that the mere capacity of the lender to influence
a borrower's decisions regarding disposal of hazardous substances was sufficient
participation in the management of the borrower's business to deny the          
protection of the secured creditor exclusion to the lender, regardless of       
whether the lender actually exercised such influence. Other judicial decisions  
did not interpret the secured creditor exclusion as narrowly as did the Fleet   
Factors decision.                                                               

  This ambiguity appears to have been resolved by the enactment of the Asset
Conservation, Lender Liability and Deposit Insurance Protection Act of 1996 (the
'Asset Conservation Act'), which took effect on September 30, 1996. The Asset   
Conservation Act provides that in order to be deemed to have participated in the
management of a mortgaged property, a lender must actually participate in the   
operational affairs of the property or of the borrower. The Asset Conservation  
Act also provides that participation in the management of the property does not 
include 'merely having the capacity to influence, or unexercised right to       
control' operations. Rather, a lender will lose the protection of the secured   
creditor exclusion only if it exercises decision making control over the        
borrower's environmental compliance and hazardous substance handling and        
disposal practices, or assumes day-to-day management of all operational         
functions of the mortgaged property. It should also be noted, however, that     
liability for costs associated with the investigation and clean-up of           
environmental contamination may also be governed by state law, which may not    
provide any specific protections to lenders, or, alternatively, may not impose  
liability on lenders at all.                                                    

CERCLA does not apply to petroleum products, and the secured creditor   
exclusion, therefore, does not apply to liability for clean-up costs associated 
with releases of petroleum contamination. Federal regulation of underground     
petroleum storage tanks (other than heating oil tanks) is governed by Subtitle I
of the federal Resource Conservation and Recovery Act ('RCRA'). The United      
States Environmental Protection Agency ('EPA') has promulgated a lender         
liability rule for underground storage tanks regulated by Subtitle I of RCRA.   
Under the EPA rule, a holder of a security interest in an underground storage   
tank, or real property containing an underground storage tank, is not considered
an operator of the underground storage tank as long as petroleum is not added   
to, stored in or dispensed from the tank by the holder of the security interest.
Moreover, amendments to RCRA, enacted in 1996, concurrently with the CERCLA     
amendments discussed in the previous paragraph, extend to the holders of        
security interests in petroleum underground storage tanks the same protections  
accorded to secured creditors under CERCLA. Again, it should be noted, however, 
that liability for clean-up of petroleum contamination may be governed by state 
law, which may not provide any specific protection for lenders or,              
alternatively, may not impose liability on lenders at all.                      

 Except as otherwise specified in the applicable Prospectus Supplement, at
the time the Mortgage Loans were originated, no environmental assessment or a   
very limited environment assessment of the Mortgaged Properties will have been  
conducted.                                                                      

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ERISA CONSIDERATIONS

    Sections 404 and 406 of the Employee Retirement Income Security Act of 1974,
as amended ('ERISA'), impose fiduciary and prohibited transaction restrictions  
on employee pension and welfare benefit plans subject to ERISA ('ERISA Plans')  
and on certain other retirement plans and arrangements, including individual    
retirement accounts and annuities, Keogh plans, bank collective investment funds
and insurance company general and separate accounts in which such ERISA Plans   
are invested. Section 4975 of the Code imposes essentially the same prohibited  
transaction restrictions on tax-qualified retirement plans described in Section 
401(a) of the Code and on individual retirement accounts described in Section   
408 of the Code (collectively, 'Tax-Favored Plans').                            

 Certain employee benefit plans, such as governmental plans (as defined in
Section 3(32) of ERISA) and, if no election has been made under Section 410(d)  
of the Code, church plans (as defined in Section 3(33) of ERISA), are not       
subject to ERISA or Section 4975 of the Code. Accordingly, assets of such plans 
may be invested in Certificates without regard to the ERISA considerations      
described below, subject to the provisions of applicable federal and state law. 
However, any such plan that is a tax-qualified plan and exempt from taxation    
under Sections 401(a) and 501(a) of the Code is subject to the prohibited       
transaction restrictions imposed under Section 503 of the Code.                 

In addition to imposing general fiduciary standards, including those of 
investment prudence and diversification and the requirement that a Plan's       
investment be made in accordance with the documents governing the Plan, Section 
406 of ERISA and Section 4975 of the Code prohibit a broad range of transactions
involving 'plan assets' of ERISA Plans and Tax-Favored Plans (collectively,     
'Plans') and persons ('parties in interest' under ERISA or 'disqualified        
persons' under the Code (collectively, 'Parties in Interest')) who have certain 
specified relationships to the Plans, unless a statutory, regulatory or         
administrative exemption is available. Certain Parties in Interest that         
participate in a prohibited transaction may be subject to penalties and/or      
excise taxes imposed under ERISA and/or Section 4975 of the Code, unless a      
statutory, regulatory or administrative exemption is available with respect to  
any such transaction.                                                           

PLAN ASSET REGULATION                                                           

An investment of Plan Assets in Certificates may cause the underlying   
Mortgage Loans, Cooperative Loans, Agency Securities, Private Securities, and/or
other assets held in a Trust to be deemed 'plan assets' of such Plan. The U.S.  
Department of Labor (the 'DOL') has issued a regulation (the 'DOL Regulation')  
concerning whether or not the assets of a Plan would be deemed to include an    
interest in the underlying assets of an entity (such as a Trust), for purposes  
of applying the general fiduciary standards of ERISA and the prohibited         
transaction provisions of ERISA and Section 4975 of the Code, when a Plan       
acquires an equity interest (such as a Certificate) in such entity. Because of  
the factual nature of certain rules in the DOL Regulation, it cannot be         
predicted whether the assets of a Plan will be deemed to include either (i) an  
interest in the assets of a entity in which the Plan holds an equity interest   
(such as a Trust), or (ii) merely the Plan's interest in the instrument         
evidencing such interest (such as a Certificate). Therefore, neither Plans nor  
certain entities in which assets of Plans are invested should acquire or hold   
Certificates in reliance upon the availability of any exception under the DOL   
Regulation. For purposes of this section, the terms 'plan assets' and 'assets of
a Plan' ('Plan Assets') have the meanings specified in the DOL Regulation and   
include an undivided interest in the underlying assets of certain entities in   
which a Plan holds an equity interest.                                          

   Under the DOL Regulations, the prohibited transaction provisions of Section
406 of ERISA and Section 4975 of the Code may apply to a Trust and cause the    
Company, the Master Servicer, any other Servicer, the Trustee, the obligor under
any credit enhancement mechanism and certain of their affiliates to be          
considered or become Parties in Interest with respect to a Plan investing in the
Certificates, whether directly or through an entity holding Plan Assets. In such
circumstances, the acquisition or holding of Certificates by or with Plan Assets
of the investing Plan could also give rise to a prohibited transaction under    
ERISA and/or Section 4975 of the Code, unless a statutory, regulatory or        
administrative exemption is available. Under the DOL Regulation, the assets of a
Plan which holds a Certificate would include such Certificate and may also be   
deemed to include the Mortgage Loans and/or other assets held in the related    
Trust. Special caution should be exercised before Plan Assets are used to       
acquire a Certificate in such circumstances, especially if, with respect to such
Plan Assets, the Company, the Master Servicer, any other Servicer, the Trustee, 
the obligor under any credit enhancement mechanism or any of their affiliates   
has                                                                             

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either (i) investment discretion with respect to such Plan Assets, or (ii)      
authority or responsibility to give (or regularly gives) investment advice with 
respect to such Plan Assets for a fee pursuant to an agreement or understanding 
that such advice will serve as a primary basis for investment decisions with    
respect to such Plan Assets.                                                    

  Any person who has discretionary authority or control as to the management
or disposition of Plan Assets, or who provides investment advice with respect to
Plan Assets for a fee (in the manner described above), is a fiduciary with      
respect to such Plan Assets. If the Mortgage Loans and/or other assets held in a
Trust were to constitute Plan Assets, any party exercising management or        
discretionary control with respect to such assets may be deemed to be a         
'fiduciary' with respect to any investing Plan and subject to the fiduciary     
requirements of ERISA and the prohibited transaction provisions of ERISA and    
Section 4975 of the Code. In addition, if the Mortgage Loans and/or other assets
held in a Trust constitute Plan Assets, the acquisition or holding of           
Certificates by, on behalf of or with Plan Assets of a Plan, and the operation  
of such Trust, may be deemed to constitute or result in a prohibited transaction
under ERISA and Section 4975 of the Code.                                       

UNDERWRITER'S EXEMPTION AND WCC EXEMPTION                                       

 The DOL has issued essentially identical individual exemptions to various
underwriters (collectively, as amended by Prohibited Transaction Exemption      
('PTE') 97-34, 62 Fed. Reg. 39021 (July 21, 1997), PTE 2000-58, 65 Fed. Reg.    
67765 (November 13, 2000) and PTE 2002-41, 67 Fed. Reg. 54487 (August 22, 2002),
the 'Underwriter's Exemption'), which generally exempt from the application of  
the prohibited transaction provisions of ERISA and Section 4975 of the Code     
certain transactions, among others, relating to (i) the servicing and operation 
of pools of certain secured obligations (such as Mortgage Loans) that are held  
in an entity, including a trust, and (ii) the purchase, sale and holding of     
securities, including pass-through certificates, issued by such entity as to    
which an underwriter (or its affiliate) which has received an Underwriter's     
Exemption is the sole underwriter or manager or co-manager of the underwriting  
syndicate or a placement agent, provided that certain conditions set forth in   
the Underwriter's Exemption are satisfied. For this purpose, the term           
'Underwriter' as used in reference to the Underwriter's Exemption includes both 
such an underwriter, placement agent or affiliate and any member of the         
underwriting syndicate or selling group with respect to the Class of            
Certificates as to which such underwriter, placement agent or affiliate is the  
manager, a co-manager or a placement agent.                                     

  If so specified in the accompanying Prospectus Supplement, broad exemptive
relief may be available under the Underwriter's Exemption or under the DOL      
authorization described immediately below. Effective August 24, 2003, the DOL   
authorized (DOL Auth. No. 2003-14E) WaMu Capital Corp. ('WCC') and its          
affiliates to rely upon the exemptive relief from certain of the prohibited     
transaction provisions of ERISA and Section 4975 of the Code available under DOL
Prohibited Transaction Class Exemption 96-62 (the 'WCC Exemption') relating to  
(i) the servicing and operation of pools of certain secured obligations (such as
Mortgage Loans) that are held in an entity, including a trust, and (ii) the     
purchase, sale and holding of securities, including pass-through certificates,  
issued by such entity as to which WCC (or its affiliate) is the sole underwriter
or manager or co-manager of the underwriting syndicate or a placement agent,    
provided that certain conditions set forth in the WCC Exemption are satisfied.  
For this purpose, the term 'Underwriter' as used in reference to the WCC        
Exemption includes both WCC or an affiliate and any member of the underwriting  
syndicate or selling group with respect to the Class of Certificates as to which
WCC or the affiliate is the manager, a co-manager or a placement agent.         

  Each Underwriter's Exemption and the WCC Exemption set forth the following
seven general conditions, which must be satisfied in order for a transaction    
involving the purchase, sale and holding of Certificates to be eligible for     
exemptive relief under either the Underwriter's Exemption or the WCC Exemption: 

    First, the acquisition of Certificates by a Plan or with Plan Assets
    must be on terms that are at least as favorable to the Plan as they would be
in an arm's-length transaction with an unrelated party.                 

       Second, the Underwriter's Exemption and the WCC Exemption only apply to
 Certificates or other securities evidencing rights and interests that are
  not subordinated to the rights and interests evidenced by the Certificates
    or other securities issued by the same trust or other entity, unless none of
 the Mortgage Loans or other assets has a loan-to-value ratio or converted
loan-to-value ratio that exceeds 100% at the date of issuance of the    
Certificates or other securities.                                       

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     Third, the Certificates, at the time of acquisition by a Plan or with
Plan Assets, must be rated in one of the four highest generic rating    
    categories by Standard & Poor's Ratings Services, Moody's Investors Service,
Inc. or Fitch Inc. (collectively, the 'Exemption Rating Agencies'). The 
  Certificates must be rated in one of the two highest generic categories by
   at least one of the Exemption Rating Agencies if the loan-to-value ratio or
converted loan-to-value ratio of any one- to four-family residential    
    Mortgage Loan held in the Trust exceeds 100% but does not exceed 125% at the
date of issuance of the Certificates. However, in that case neither the 
  Underwriter's Exemption nor the WCC Exemption will apply (i) to any of the
Certificates if (x) any Mortgage Loan or other asset held in the Trust  
(other than a one- to four-family residential Mortgage Loan) has a      
 loan-to-value ratio or converted loan-to-value ratio that exceeds 100% at
the date of issuance of the Certificates or (y) any one- to four-family 
residential Mortgage Loan has a loan-to-value ratio or converted        
loan-to-value ratio that exceeds 125% at the date of issuance of the    
Certificates or (ii) to any Subordinated Certificates.                  

       Fourth, the Trustee must not be an affiliate of any other member of the
  Restricted Group, other than an Underwriter. The Restricted Group consists
 of any Underwriter, the Company, the Master Servicer, any other Servicer,
the Trustee, the swap counterparty under any swap arrangement and any   
    mortgagor with respect to assets of a Trust constituting more than 5% of the
  aggregate unamortized principal balance of the assets held in the Trust as
of the date of initial issuance of the Certificates.                    

       Fifth, the sum of all payments made to and retained by the Underwriters
 must represent not more than reasonable compensation for underwriting the
 Certificates; the sum of all payments made to and retained by the Company
pursuant to the assignment of the assets to the Trust must represent not
more than the fair market value of such obligations; and the sum of all 
  payments made to and retained by the Master Servicer or any other Servicer
must represent not more than reasonable compensation for such person's  
services under the related Pooling Agreement and reimbursement of such  
person's reasonable expenses in connection therewith.                   

Sixth, the Plan or other person investing Plan Assets in the    
    Certificates must be an accredited investor (as defined in Rule 501(a)(1) of
Regulation D under the Securities Act of 1933, as amended).             

     Seventh, (i) the Trust must consist solely of assets of the type that
have been included in other investment pools; (ii) securities evidencing
   interests in such other investment pools must have been rated in one of the
    four highest categories of one of the Exemption Rating Agencies for at least
   one year prior to the acquisition of Certificates by or with Plan Assets of
   a Plan in reliance on the Underwriter's Exemption or the WCC Exemption; and
   (iii) securities in such other investment pools must have been purchased by
   investors (other than Plans) for at least one year prior to any acquisition
of Certificates by or with Plan Assets of a Plan in reliance on the     
Underwriter's Exemption or the WCC Exemption.                           

The exemptive relief afforded by the Underwriter's Exemption and the WCC
Exemption does not apply to any securities where the related trust or other     
entity contains revolving credit loans or unsecured loans. In addition, except  
as otherwise specified in the accompanying Prospectus Supplement, the exemptive 
relief afforded by the Underwriter's Exemption or the WCC Exemption may not     
apply to any securities where the related trust or other entity contains certain
purchase obligations, a swap or a pre-funding arrangement.                      

Any fiduciary or other person who proposes to use Plan Assets to acquire
Certificates or other securities in reliance upon the Underwriter's Exemption or
the WCC Exemption must make its own determination as to whether the general     
conditions set forth above will be satisfied with respect to its acquisition and
holding of such Certificates or other securities.                               

If the general conditions of the Underwriter's Exemption or the WCC     
Exemption are satisfied, the Underwriter's Exemption or the WCC Exemption, as   
applicable, may provide exemptive relief from:                                  

       (a) The restrictions imposed by Sections 406(a) and 407(a) of ERISA and
    Sections 4975(c)(1) through (D) of the Code in connection with the direct or
indirect sale, exchange, transfer or holding, or the direct or indirect 
    acquisition or disposition in the secondary market, of Certificates or other
securities by or with Plan Assets of a Plan, provided that no exemptive 
relief is provided from the restrictions of Sections 406(a)(1)(E) and   
406(a)(2) of ERISA for the acquisition or holding of a                  

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   Certificate or other security by or with Plan Assets of a Plan sponsored by
 any member of the Restricted Group (an 'Excluded Plan'), or by any person
  who has discretionary authority or renders investment advice for a fee (as
described above) with respect to Plan Assets of such Excluded Plan;     

        (b) When certain additional conditions are met, the restrictions imposed
  by Sections 406(b)(1) and (b)(2) of ERISA and Section 4975(c)(1)(E) of the
Code in connection with (i) the direct or indirect sale, exchange or    
transfer of Certificates or other securities in the initial issuance of 
    Certificates or other securities between the Company or an Underwriter and a
  Plan when the person who has discretionary authority or renders investment
   advice for a fee (as described above) with respect to the investment of the
   relevant Plan Assets in the Certificates or other securities is a mortgagor
    with respect to 5% or less of the fair market value of the assets of a Trust
  (or its affiliate), (ii) the direct or indirect acquisition or disposition
   in the secondary market of Certificates or other securities by or with Plan
   Assets of a Plan, and (iii) the holding of Certificates or other securities
by or with Plan Assets of a Plan; and                                   

    (c) The restrictions imposed by Sections 406 and 407(a) of ERISA and
   Section 4975(c) of the Code for certain transactions in connection with the
servicing, management and operation of the Mortgage Pools, subject to   
  certain specific conditions which the Company expects will be satisfied if
  the general conditions of the Underwriter's Exemption or the WCC Exemption
are satisfied.                                                          

    The Underwriter's Exemption and the WCC Exemption also may provide exemptive
relief from the restrictions imposed by Sections 406(a) and 407(a) of ERISA and 
Sections 4975(c)(1)(A) through (D) of the Code if such restrictions would       
otherwise be deemed to apply merely because a person is deemed to be a Party in 
Interest with respect to a Plan investing in the Certificates or other          
securities (whether directly or through an entity holding Plan Assets) by virtue
of providing services to the Plan (or such Plan Assets), or by virtue of having 
certain specified relationships to such a person, solely as a result of the     
Plan's ownership of Certificates or other securities.                           

Before purchasing a Certificate or other security in reliance upon the  
Underwriter's Exemption or the WCC Exemption, a fiduciary or other investor of  
Plan Assets should itself confirm that (i) the Certificates or other securities 
constitute 'securities' for purposes of the Underwriter's Exemption or the WCC  
Exemption, as applicable, and (ii) the specific and general conditions and other
requirements set forth in the Underwriter's Exemption or the WCC Exemption would
be satisfied. In addition to making its own determination as to the availability
of the exemptive relief provided in the Underwriter's Exemption or the WCC      
Exemption, as applicable, the fiduciary or other Plan Asset investor should     
consider its general fiduciary obligations under ERISA in determining whether to
purchase any Certificates or other securities with Plan Assets.                 

OTHER EXEMPTIONS                                                                

Any fiduciary or other person who proposes to use Plan Assets to acquire
Certificates or other securities should consult with its legal counsel with     
respect to the potential applicability of ERISA and the Code to such investment 
and the availability of exemptive relief under the Underwriter's Exemption, the 
WCC Exemption or any other prohibited transaction exemption in connection       
therewith. In particular, in connection with an acquisition of Certificates or  
other securities representing a beneficial ownership interest in a pool of      
single-family residential first or second Mortgage Loans or Agency Securities,  
such fiduciary or other Plan Asset investor should also consider the            
availability of exemptive relief under Prohibited Transaction Class Exemption   
('PTCE') 83-1 for certain transactions involving mortgage pool investment       
trusts. However, PTCE 83-1 does not provide exemptive relief with respect to    
Certificates or other securities evidencing an interest in a Trust with assets  
that include Cooperative Loans, Private Securities, mortgage loans secured by   
third or more junior liens, contracts, multifamily or mixed-use mortgage loans, 
or certain other assets, or which contain a swap or a pre-funding arrangement.  
In addition, such fiduciary or other Plan Asset investor should consider the    
availability of other class exemptions granted by the DOL, which provide relief 
from certain of the prohibited transaction provisions of ERISA and Section 4975 
of the Code, including Sections I and III of PTCE 95-60, regarding transactions 
by insurance company general accounts. The applicable Prospectus Supplement may 
contain additional information regarding the application of the Underwriter's   
Exemption, the WCC Exemption, PTCE 83-1, PTCE 95-60 or other DOL class          
exemptions with respect to the Certificates or other securities offered thereby.
There can be no assurance that any of these exemptions will apply with respect  

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to any particular Plan's or other Plan Asset investor's investment in the       
Certificates or other securities or, even if an exemption were applicable, that 
such exemption would apply to all prohibited transactions that may occur in     
connection with such an investment.                                             

INSURANCE COMPANY GENERAL ACCOUNTS                                              

  Insurance companies contemplating the investment of general account assets
in the Certificates should consult with their legal advisors with respect to the
applicability of Section 401(c) of ERISA. The DOL issued final regulations under
Section 401(c) which were published in the Federal Register on January 5, 2000  
and generally became applicable on July 5, 2001.                                

REPRESENTATIONS FROM INVESTING PLANS                                            

If the criteria specified in the Underwriter's Exemption or the WCC     
Exemption, as applicable, as described above are not satisfied by one or more   
Classes of Certificates or other securities, or by a trust or the Mortgage Loans
and other assets held by the Trust, except as otherwise specified in the        
accompanying Prospectus Supplement, transfers of those securities to a Plan, to 
a trustee or other person acting on behalf of any Plan, or to any other person  
using Plan Assets to effect the acquisition, will not be registered by the      
Trustee unless the transferee provides the Company and the Trustee with an      
opinion of counsel satisfactory to the Company and the Trustee, which opinion   
will not be at the expense of the Company, the Trustee or the Master Servicer,  
that the acquisition of such Certificates or other securities by or on behalf of
such Plan or with Plan Assets is permissible under applicable law, will not     
constitute or result in any non-exempt prohibited transaction under ERISA or    
Section 4975 of the Code, and will not subject the Company, the Trustee or the  
Master Servicer to any obligation in addition to those undertaken in the Pooling
Agreement. Except as otherwise specified in the accompanying Prospectus         
Supplement, each beneficial owner of a Subordinated Certificate offered by this 
Prospectus and the accompanying Prospectus Supplement (or any interest therein) 
shall be deemed to have represented, by virtue of its acquisition or holding of 
such Certificate (or interest therein), that either (i) it is not a Plan, a     
trustee or other person acting on behalf of any Plan, or any other person using 
Plan Assets to effect such acquisition or holding, (ii) it has acquired and is  
holding such Subordinated Certificate in reliance on the Underwriter's Exemption
or the WCC Exemption, as applicable, and the Subordinated Certificate was rated,
at the time of acquisition, in one of the four highest generic rating categories
by at least one of the Exemption Rating Agencies or (iii)(1) such acquirer or   
holder is an insurance company, (2) the source of funds used to acquire or hold 
such security (or interest therein) is an 'insurance company general account'   
(as defined in PTCE 95-60), and (3) the conditions set forth in Sections I and  
III of PTCE 95-60 have been satisfied.                                          

If any Subordinated Certificate (or any interest therein) is acquired or
held in violation of the conditions described in the preceding paragraph, the   
next preceding permitted beneficial owner will be treated as the beneficial     
owner of the Subordinated Certificate, retroactive to the date of transfer to   
the purported beneficial owner. Any purported beneficial owner whose acquisition
or holding of any Subordinated Certificate (or interest therein) was effected in
violation of the conditions described in the preceding paragraph shall indemnify
and hold harmless the Company, the Trustee, the Master Servicer, any            
subservicer, the underwriter and the Trust from and against any and all         
liabilities, claims, costs or expenses incurred by such parties as a result of  
such acquisition or holding.                                                    

TAX-EXEMPT PLAN INVESTORS                                                       

   A Plan which is exempt from federal income taxation pursuant to Section 501
of the Code generally will be subject to federal income taxation to the extent  
that its income constitutes unrelated business taxable income (or 'UBTI') within
the meaning of Section 512 of the Code. Excess inclusions of a REMIC allocated  
to a REMIC Residual Certificate held by such a Plan will be considered UBTI and 
thus will be subject to federal income tax. See 'Certain Federal Income Tax     
Consequences -- Taxation of Owners of REMIC Residual Certificates -- Excess     
Inclusions' and ' -- Tax-Exempt Investors'. In addition, the exemptive relief   
afforded by the Underwriter's Exemption and the WCC Exemption does not apply to 
the purchase, sale or holding of any class of REMIC Residual Certificates.      

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CONSULTATION WITH COUNSEL                                                       

There can be no assurance that the Underwriter's Exemption, the WCC     
Exemption or any other exemption granted by the DOL will apply with respect to  
any particular Plan that acquires Certificates (whether directly or through an  
entity holding Plan Assets) or, even if all of the conditions specified in the  
Underwriter's Exemption or the WCC Exemption, as applicable, were satisfied,    
that exemptive relief would be available for all transactions involving a Trust.
Prospective Plan Asset investors should consult with their legal counsel        
concerning the impact of ERISA and the Code and the potential consequences in   
their specific circumstances prior to making an investment in Certificates.     

  Any fiduciary or other person who proposes to acquire or hold Certificates
on behalf of a Plan or with Plan Assets should consult with its legal counsel   
with respect to the potential applicability of the fiduciary responsibility     
provisions of ERISA and the prohibited transaction provisions of ERISA and      
Section 4975 of the Code to the proposed investment and the availability of     
exemptive relief under the Underwriter's Exemption, the WCC Exemption, PTCE     
83-1, Sections I and III of PTCE 95-60, and/or any other class exemption granted
by the DOL. In addition to making its own determination as to the availability  
of the exemptive relief provided in the Underwriter's Exemption, the WCC        
Exemption or any other DOL exemption, any fiduciary of an ERISA-subject Plan    
should consider its general fiduciary obligations under ERISA in determining    
whether to purchase Certificates on behalf of such Plan.                        

Any fiduciary or other person who proposes to use Plan Assets to acquire
Certificates should consult with its own legal counsel with respect to the      
potential consequences under ERISA and the Code of the acquisition and ownership
of Certificates.                                                                

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CERTAIN FEDERAL INCOME TAX CONSEQUENCES 

 The following is a general discussion of the anticipated material federal
income tax consequences of the purchase, ownership and disposition of the       
Certificates offered hereunder. It does not purport to discuss all federal      
income tax consequences that may be applicable to particular categories of      
investors, some of which may be subject to special rules and does not address   
the tax consequences of persons holding Certificates as part of a hedge or      
hedging transaction. Further, the authorities on which this discussion is based 
are subject to change or differing interpretations, which changes or differing  
interpretations could apply retroactively. This discussion does not address the 
state or local tax consequences of the purchase, ownership and disposition of   
such Certificates. Investors should consult their own tax advisors in           
determining the federal, state, local or other tax consequences to them of the  
purchase, ownership and disposition of the Certificates offered hereunder.      

The following discussion addresses certificates ('REMIC Certificates')  
representing interests in a Mortgage Pool ('REMIC Mortgage Pool') as to which   
the Company, in the case where the Company will be a Master Servicer for a      
Series or in the case where there will be no Master Servicer for a Series, or   
the Servicing Entity, in the case where the Servicing Entity is the only Master 
Servicer for a Series, will cause to elect treatment as a real estate mortgage  
investment conduit ('REMIC') under Sections 860A through 860G ('REMIC           
Provisions') of the Code. Under the REMIC Provisions, REMICs may issue 'regular'
interests and must issue one and only one class of 'residual' interests. A REMIC
Certificate representing a regular interest in a REMIC Mortgage Pool will be    
referred to as a 'REMIC Regular Certificate' and a REMIC Certificate            
representing a residual interest in a REMIC Mortgage Pool will be referred to as
a 'REMIC Residual Certificate'.                                                 

   The following discussion is based in part upon the rules governing original
issue discount that are set forth in Code Sections 1271 through 1273 and 1275   
and in Treasury regulations issued under the original issue discount provisions 
of the Code (the 'OID Regulations'), and the Treasury regulations issued under  
the provisions of the Code relating to REMICs (the 'REMIC Regulations'). The OID
Regulations generally are effective with respect to debt instruments issued on  
or after April 4, 1994.                                                         

CLASSIFICATION OF REMICS                                                        

With respect to each Series of REMIC Certificates, Orrick, Herrington & 
Sutcliffe LLP, special counsel to the Company, will deliver their opinion       
generally to the effect that, assuming (i) a REMIC election is made timely in   
the required form, (ii) each Master Servicer or Servicing Entity, as applicable,
complies with all provisions of the related Pooling Agreement, (iii) certain    
representations set forth in the Pooling Agreement are true, and (iv) there is  
continued compliance with applicable provisions of the Code, as it may be       
amended from time to time, and applicable Treasury regulations issued           
thereunder, the related REMIC Mortgage Pool will qualify as a REMIC and the     
classes of interests offered will be considered to be regular interests or      
residual interests in that REMIC Mortgage Pool within the meaning of the REMIC  
Provisions.                                                                     

    Holders of REMIC Certificates should be aware that, if an entity electing to
be treated as a REMIC fails to comply with one or more of the ongoing           
requirements of the Code for REMIC status during any taxable year, the Code     
provides that the entity will not be treated as a REMIC for such year and       
thereafter. In such event, an entity electing to be treated as a REMIC may be   
taxable as a separate corporation under Treasury regulations, and the related   
REMIC Certificates may not be accorded the status described below under the     
heading 'Characterization of Investments in REMIC Certificates'. In the case of 
an inadvertent termination of REMIC status, the Code provides the Treasury      
Department with authority to issue regulations providing relief. Any such       
relief, however, may be accompanied by sanctions, such as the imposition of a   
corporate tax on all or a portion of the REMIC's income for the period of time  
in which the requirements for REMIC status are not satisfied.                   

CHARACTERIZATION OF INVESTMENTS IN REMIC CERTIFICATES                           

In general, REMIC Certificates are not treated for federal income tax   
purposes as ownership interests in the assets of a REMIC Mortgage Pool. However,
(i) REMIC Certificates held by a domestic building and loan association will    
constitute a 'regular or residual interest in a REMIC' within the meaning of    

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Code Section 7701(a)(19)(C)(xi) in the same proportion that the Assets would be 
treated as 'loans . . . secured by an interest in real property' within the     
meaning of Code Section 7701(a)(19)(C)(v) or as other assets described in Code  
Section 7701(a)(19)(C); and (ii) REMIC Certificates held by a real estate       
investment trust will constitute 'real estate assets' within the meaning of Code
Section 856(c)(4)(A), and interest on the REMIC Certificates will be considered 
'interest on obligations secured by mortgages on real property or on interests  
in real property' within the meaning of Code Section 856(c)(3)(B) in the same   
proportion that, respectively, the Assets would be treated as 'interests in real
property' as defined in Code Section 856(c)(5)(C) (or, as provided in the       
Committee Report, as 'real estate assets' as defined in Code Section            
856(c)(5)(B)) or as income from the Assets would be treated as 'interest on     
obligations secured by mortgages on real property or on interests in real       
property.' Moreover, if 95% or more of the Assets qualify for any of the        
foregoing treatments, the REMIC Certificates will qualify for the corresponding 
status in their entirety. Investors should be aware that the investment of      
amounts in any reserve account in assets not so qualifying would, and holding   
property acquired by foreclosure pending sale might, reduce the amount of the   
REMIC Certificate that would qualify for the foregoing treatment. The REMIC     
Regulations provide that payments on Mortgage Loans held pending distribution   
are considered part of the Mortgage Loans for purposes of Code Section          
856(c)(4)(A); it is unclear whether such collected payments would be so treated 
for purposes of Code Section 7701(a)(19)(c)(v), but there appears to be no      
reason why analogous treatment should not be given to such collected payments   
under that provision. The determination as to the percentage of the REMIC's     
assets that will constitute assets described in the foregoing sections of the   
Code will be made with respect to each calendar quarter based on the average    
adjusted basis of each category of the assets held by the REMIC during such     
calendar quarter. The REMIC will report those determinations to                 
Certificateholders in the manner and at the times required by applicable        
Treasury regulations. The applicable Prospectus Supplement or the related       
Current Report on Form 8-K for each Series of REMIC Certificates will describe  
the Assets as of the Cut-Off Date. REMIC Certificates held by certain financial 
institutions will constitute 'evidence of indebtedness' within the meaning of   
Code Section 582(c)(1); in addition, REMIC Regular Certificates acquired by a   
REMIC in accordance with the requirements of Section 860G(a)(3)(C) or Section   
860G(a)(4)(B) of the Code will be treated as 'qualified mortgages' for purposes 
of Code Section 860D(a)(4).                                                     

TAXATION OF OWNERS OF REMIC REGULAR CERTIFICATES                                

Except as otherwise stated in this discussion, the REMIC Regular        
Certificates will be treated for federal income tax purposes as debt instruments
issued by the REMIC Mortgage Pool and not as ownership interests in the REMIC   
Mortgage Pool or its Assets. In general, interest, original issue discount and  
market discount paid or accrued on a REMIC Regular Certificate will be treated  
as ordinary income to the holder of such REMIC Regular Certificate.             
Distributions in reduction of the stated redemption price at maturity of the    
REMIC Regular Certificate will be treated as a return of capital to the extent  
of such holder's basis in such REMIC Regular Certificate. Holders of REMIC      
Regular Certificates that otherwise report income under a cash method of        
accounting will be required to report income with respect to REMIC Regular      
Certificates under an accrual method.                                           

1. Original Issue Discount                                                      

Certain REMIC Regular Certificates may be issued with 'original issue   
discount' within the meaning of Code Section 1273(a). Any holders of REMIC      
Regular Certificates issued with original issue discount generally will be      
required to include original issue discount in income as it accrues, in         
accordance with a constant interest method that takes into account the          
compounding of interest, in advance of the receipt of the cash attributable to  
such income. The Company will report annually (or more often if required) to the
Internal Revenue Service ('IRS') and to Certificateholders such information with
respect to the original issue discount accruing on the REMIC Regular            
Certificates as may be required under Code Section 6049 and the regulations     
thereunder. See ' -- Reporting and Other Administrative Matters of REMICS'      
below.                                                                          

   Rules governing original issue discount are set forth in Code Sections 1271
through 1273 and 1275 and, to some extent, in the OID Regulations. Code Section 
1272(a)(6) provides special original issue discount rules applicable to REMIC   
Regular Certificates. Regulations have not yet been proposed or adopted under   
Section 1272(a)(6) of the Code. Further, application of the OID Regulations to  
the REMIC                                                                       

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Regular Certificates remains unclear in some respects because the OID           
Regulations generally purport not to apply to instruments to which Section      
1272(a)(6) applies such as REMIC Regular Certificates, and separately because   
they either do not address, or are subject to varying interpretations with      
regard to, several relevant issues.                                             

Code Section 1272(a)(6) requires that a mortgage prepayment assumption  
('Prepayment Assumption') be used in computing the accrual of original issue    
discount on REMIC Regular Certificates and for certain other federal income tax 
purposes. The Prepayment Assumption is to be determined in the manner prescribed
in Treasury regulations. To date, no such regulations have been promulgated. The
Committee Report indicates that the regulations will provide that the Prepayment
Assumption, if any, used with respect to a particular transaction must be the   
same as that used by the parties in pricing the transaction. Unless otherwise   
specified in the applicable Prospectus Supplement, the Company will use a       
percentage of the Basic Prepayment Assumption (or such other Prepayment         
Assumption as may be specified in the applicable Prospectus Supplement) in      
reporting original issue discount that is consistent with this standard.        
However, the Company does not make any representation that the Mortgage Loans   
will in fact prepay at that percentage of the Basic Prepayment Assumption or at 
any other rate. Each investor must make its own decision as to the appropriate  
prepayment assumption to be used in deciding whether or not to purchase any of  
the REMIC Regular Certificates. The Prospectus Supplement with respect to a     
Series of REMIC Certificates will disclose the percentage of the Basic          
Prepayment Assumption (or such other Prepayment Assumption as may be specified  
therein) to be used in reporting original issue discount, if any, and for       
certain other federal income tax purposes.                                      

  The total amount of original issue discount on a REMIC Regular Certificate
is the excess of the 'stated redemption price at maturity' of the REMIC Regular 
Certificate over its 'issue price'. Except as discussed in the following two    
paragraphs, in general, the issue price of a particular Class of REMIC Regular  
Certificates offered hereunder will be the price at which a substantial amount  
of REMIC Regular Certificates of that Class are first sold to the public        
(excluding bond houses and brokers).                                            

    If a REMIC Regular Certificate is sold with accrued interest that relates to
a period prior to the issue date of such REMIC Regular Certificate, the amount  
paid for the accrued interest will be treated instead as increasing the issue   
price of the REMIC Regular Certificate. In addition, that portion of the first  
interest payment in excess of interest accrued from the Closing Date to the     
first Distribution Date will be treated for federal income tax reporting        
purposes as includible in the stated redemption price at maturity of the REMIC  
Regular Certificate, and as excludible from income when received as a payment of
interest on the first Distribution Date. The OID Regulations suggest that some  
or all of this pre-issuance accrued interest 'may' be treated as a separate     
asset (and hence not includible in a REMIC Regular Certificate's issue price or 
stated redemption price at maturity), whose cost is recovered entirely out of   
interest paid on the first Distribution Date. It is unclear how such treatment  
would be elected under the OID Regulations and whether an election could be made
unilaterally by a Certificateholder.                                            

 The stated redemption price at maturity of a REMIC Regular Certificate is
equal to the total of all payments to be made on such Certificate other than    
'qualified stated interest'. Under the OID Regulations, 'qualified stated       
interest' is interest that is unconditionally payable at least annually during  
the entire term of the Certificate at either (i) a single fixed rate that       
appropriately takes into account the length of the interval between payments or 
(ii) the current values of a single 'qualified floating rate' or 'objective     
rate' (each, a 'Single Variable Rate'). A 'current value' is the value of a     
variable rate on any day that is no earlier than three months prior to the first
day on which that value is in effect and no later than one year following that  
day. A 'qualified floating rate' is a rate whose variations can reasonably be   
expected to measure contemporaneous variations in the cost of newly borrowed    
funds in the currency in which the Certificate is denominated. Such a rate      
remains qualified even though it is multiplied by a fixed, positive multiple not
exceeding 1.35, increased or decreased by a fixed rate, or both. Certain        
combinations of rates constitute a single qualified floating rate, including (i)
interest stated at a fixed rate for an initial period of less than one year     
followed by a qualified floating rate if the value of the floating rate at the  
closing date is intended to approximate the fixed rate, and (ii) two or more    
qualified floating rates that can be expected to have approximately the same    
values throughout the term of the Certificate. A combination of such rates is   
conclusively presumed to be a single floating rate if the values of all rates on
the closing date are within 0.25% of each other. A variable rate that is subject
to an interest rate cap,                                                        

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floor, 'governor' or similar restriction on rate adjustment may be a qualified  
floating rate only if such restriction is fixed throughout the term of the      
instrument, or is not reasonably expected as of the closing date to cause the   
yield on the debt instrument to differ significantly from the expected yield    
absent the restriction. An 'objective rate' is a rate (other than a qualified   
floating rate) determined using a single formula fixed for the life of the      
Certificate, which is based on (i) one or more qualified floating rates         
(including a multiple or inverse of a qualified floating rate), (ii) one or more
rates each of which would be a qualified floating rate for a debt instrument    
denominated in a foreign currency, (iii) the yield or changes in price of one or
more items of 'actively traded' personal property, (iv) a combination of rates  
described in (i), (ii) and (iii), or (v) a rate designated by the IRS. However, 
a variable rate is not an objective rate if it is reasonably expected that the  
average value of the rate during the first half of the Certificate's term will  
differ significantly from the average value of such rate during the final half  
of its term. A combination of interest stated at a fixed rate for an initial    
period of less than one year followed by an objective rate is treated as a      
single objective rate if the value of the objective rate at the closing date is 
intended to approximate the fixed rate; such a combination of rates is          
conclusively presumed to be a single objective rate if the objective rate on the
closing date does not differ from the fixed rate by more than 0.25%. The        
qualified stated interest payable with respect to certain variable rate debt    
instruments not bearing stated interest at a Single Variable Rate generally is  
determined under the OID Regulations by converting such instruments into fixed  
rate debt instruments. Instruments qualifying for such treatment generally      
include those providing for stated interest at (i) more than one qualified      
floating rates, or at (ii) a single fixed rate and (a) one or more qualified    
floating rates or (b) a single 'qualified inverse floating rate' (each, a       
'Multiple Variable Rate'). A qualified inverse floating rate is an objective    
rate equal to a fixed rate reduced by a qualified floating rate, the variations 
in which can reasonably be expected to inversely reflect contemporaneous        
variations in the cost of newly borrowed funds (disregarding permissible rate   
caps, floors, governors and similar restrictions such as are described above).  
Under these rules, some of the payments of interest on a Certificate bearing a  
fixed rate of interest for an initial period followed by a qualified floating   
rate of interest in subsequent periods could be treated as included in the      
stated redemption price at maturity if the initial fixed rate were to differ    
sufficiently from the rate that would have been set using the formula applicable
to subsequent periods. See ' -- Variable Rate Certificates'. REMIC Regular      
Certificates offered hereby other than Certificates providing for variable rates
of interest or for the accretion of interest are not anticipated to have stated 
interest other than 'qualified stated interest', but if any such REMIC Regular  
Certificates are so offered, appropriate disclosures will be made in the        
Prospectus Supplement. Some or all of the payments on REMIC Regular Certificates
providing for the accretion of interest will be included in the stated          
redemption price at maturity of such Certificates.                              

   Under a de minimis rule in the Code, as interpreted in the OID Regulations,
original issue discount on a REMIC Regular Certificate will be considered to be 
zero if such original issue discount is less than 0.25% of the stated redemption
price at maturity of the REMIC Regular Certificate multiplied by the weighted   
average life of the REMIC Regular Certificate. For this purpose, the weighted   
average life of the REMIC Regular Certificate is computed as the sum of the     
amounts determined by multiplying the amount of each payment under the          
instrument (other than a payment of qualified stated interest) by a fraction,   
whose numerator is the number of complete years from the issue date until such  
payment is made, and whose denominator is the stated redemption price at        
maturity of such REMIC Regular Certificate. The IRS may be anticipated to take  
the position that this rule should be applied taking into account the Prepayment
Assumption and the effect of any anticipated investment income. Under the OID   
Regulations, REMIC Regular Certificates bearing only qualified stated interest  
except for any 'teaser' rate, interest holiday or similar provision would be    
treated as subject to the de minimis rule if the greater of the deferred or     
foregone interest or the other original issue discount is less than such de     
minimis amount.                                                                 

    The OID Regulations generally would treat de minimis original issue discount
as includible in income as each principal payment is made, based on the product 
of the total amount of such de minimis original issue discount and a fraction,  
whose numerator is the amount of such principal payment and whose denominator is
the stated principal amount of the REMIC Regular Certificate. The OID           
Regulations also would permit a Certificateholder to elect to accrue de minimis 
original issue discount into income currently based on a constant yield method. 
See 'Taxation of Owners of REMIC Regular Certificates -- Market Discount and    
Premium'.                                                                       

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   Each holder of a REMIC Regular Certificate must include in gross income the
sum of the 'daily portions' of original issue discount on its REMIC Regular     
Certificate for each day during its taxable year on which it held such REMIC    
Regular Certificate. For this purpose, in the case of an original holder of a   
REMIC Regular Certificate, the daily portions of original issue discount will be
determined as follows. A calculation will first be made of the portion of the   
original issue discount that accrued during each accrual period, that is, unless
otherwise stated in the applicable Prospectus Supplement, each period that      
begins or ends on a date that corresponds to a Distribution Date on the REMIC   
Regular Certificate and begins on the first day following the immediately       
preceding accrual period (beginning on the Closing Date in the case of the first
such period). For any accrual period such portion will equal the excess, if any,
of (i) the sum of (A) the present value of all of the distributions remaining to
be made on the REMIC Regular Certificate, if any, as of the end of the accrual  
period and (B) the distribution made on such REMIC Regular Certificate during   
the accrual period of amounts included in the stated redemption price at        
maturity, over (ii) the adjusted issue price of such REMIC Regular Certificate  
at the beginning of the accrual period. The present value of the remaining      
payments referred to in the preceding sentence will be calculated based on (i)  
the yield to maturity of the REMIC Regular Certificate, calculated as of the    
settlement date, giving effect to the Prepayment Assumption, (ii) events        
(including actual prepayments) that have occurred prior to the end of the       
accrual period, and (iii) the Prepayment Assumption. The adjusted issue price of
a REMIC Regular Certificate at the beginning of any accrual period will equal   
the issue price of such Certificate, increased by the aggregate amount of       
original issue discount with respect to such REMIC Regular Certificate that     
accrued in prior accrual periods, and reduced by the amount of any distributions
made on such REMIC Regular Certificate in prior accrual periods of amounts      
included in the stated redemption price at maturity. The original issue discount
accruing during any accrual period will be allocated ratably to each day during 
the period to determine the daily portion of original issue discount for each   
day. With respect to an accrual period between the settlement date and the first
Distribution Date on the REMIC Regular Certificate (notwithstanding that no     
distribution is scheduled to be made on such date) that is shorter than a full  
accrual period, the OID Regulations permit the daily portions of original issue 
discount to be determined according to any reasonable method.                   

 A subsequent purchaser of a REMIC Regular Certificate that purchases such
REMIC Regular Certificate at a cost (not including payment for accrued qualified
stated interest) less than its remaining stated redemption price at maturity    
will also be required to include in gross income, for each day on which it holds
such REMIC Regular Certificate, the daily portions of original issue discount   
with respect to such REMIC Regular Certificate, but reduced, if such cost       
exceeds the 'adjusted issue price', by an amount equal to the product of (i)    
such daily portions and (ii) a constant fraction, whose numerator is such excess
and whose denominator is the sum of the daily portions of original issue        
discount on such REMIC Regular Certificate for all days on or after the day of  
purchase. The adjusted issue price of a REMIC Regular Certificate on any given  
day is equal to the sum of the adjusted issue price (or, in the case of the     
first accrual period, the issue price) of the REMIC Regular Certificate at the  
beginning of the accrual period during which such day occurs and the daily      
portions of original issue discount for all days during such accrual period     
prior to such day, reduced by the aggregate amount of distributions previously  
made other than distributions of qualified stated interest.                     

    Variable Rate Certificates. Purchasers of REMIC Regular Certificates bearing
a variable rate of interest should be aware that there is uncertainty concerning
the application of Section 1272(a)(6) of the Code and the OID Regulations to    
such Certificates. In the absence of other authority, the Company intends to be 
guided by the provisions of the OID Regulations governing variable rate debt    
instruments in adapting the provisions of Section 1272(a)(6) of the Code        
to such Certificates for the purpose of preparing reports furnished to          
Certificateholders. The effect of the application of such provisions generally  
will be to cause Certificateholders holding Certificates bearing interest at a  
Single Variable Rate to take into account for each period an amount             
corresponding approximately to the sum of (i) the qualified stated interest,    
accruing on the outstanding face amount of the REMIC Regular Certificate as the 
stated interest rate for that Certificate varies from time to time and (ii) the 
amount of original issue discount that would have been attributable to that     
period on the basis of a constant yield to maturity for a bond issued at the    
same time and issue price as the REMIC Regular Certificate, having the same face
amount and schedule of payments of principal as such Certificate, subject to the
same Prepayment Assumption, and bearing interest at a fixed rate equal to the   
value of the applicable qualified floating rate or qualified inverse floating   
rate                                                                            

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in the case of a Certificate providing for either such rate, or equal to the    
fixed rate that reflects the reasonably expected yield on the Certificate in the
case of a Certificate providing for an objective rate other than an inverse     
floating rate, in each case as of the issue date. Certificateholders holding    
REMIC Regular Certificates bearing interest at a Multiple Variable Rate         
generally will take into account interest and original issue discount under a   
similar methodology, except that the amounts of qualified stated interest and   
original issue discount attributable to such a Certificate first will be        
determined for an equivalent fixed rate debt instrument, the assumed fixed rates
for which are (a) for each qualified floating rate, the value of each such rate 
as of the closing date (with appropriate adjustment for any differences in      
intervals between interest adjustment dates), (b) for a qualified inverse       
floating rate, the value of the rate as of the closing date, (c) for any other  
objective rate, the fixed rate that reflects the yield that is reasonably       
expected for the Certificate, and (d) for an actual fixed rate, such            
hypothetical fixed rate as would result under (a) or (b) if the actual fixed    
rate were replaced by a hypothetical qualified floating rate or qualified       
inverse floating rate such that the fair market value of the Certificate as of  
the issue date would be approximately the same as that of an otherwise identical
debt instrument providing for the hypothetical variable rate rather than the    
actual fixed rate. If the interest paid or accrued with respect to a Multiple   
Variable Rate Certificate during an accrual period differs from the assumed     
fixed interest rate, such difference will be an adjustment (to interest or      
original issue discount, as applicable) to the Certificateholder's taxable      
income for the taxable period or periods to which such difference relates.      
Additionally, purchasers of such Certificates should be aware that the          
provisions of the OID Regulations applicable to variable rate debt instruments  
have been limited and may not apply to some REMIC Regular Certificates having   
variable rates. If such a Certificate is not governed by the provisions of the  
OID Regulations applicable to variable rate debt instruments, it may be subject 
to provisions of proposed Treasury Regulations applicable to instruments having 
contingent payments. The application of those provisions to instruments such as 
variable rate REMIC Regular Certificates is subject to differing                
interpretations. Prospective purchasers of variable rate REMIC Regular          
Certificates are advised to consult their tax advisors concerning the tax       
treatment of such Certificates.                                                 

2. Market Discount and Premium                                                  

  A Certificateholder that purchases a REMIC Regular Certificate at a market
discount, that is, at a purchase price less than the adjusted issue price (as   
defined under ' -- Taxation of Owners of REMIC Regular Certificates -- Original 
Issue Discount') of such REMIC Regular Certificate generally will recognize     
market discount upon receipt of each distribution of principal. In particular,  
such a holder will generally be required to allocate each payment of principal  
on a REMIC Regular Certificate first to accrued market discount, and to         
recognize ordinary income to the extent such principal payment does not exceed  
the aggregate amount of accrued market discount on such REMIC Regular           
Certificate not previously included in income. Such market discount must be     
included in income in addition to any original issue discount includible in     
income with respect to such REMIC Regular Certificate.                          

    A Certificateholder may elect to include market discount in income currently
as it accrues, rather than including it on a deferred basis in accordance with  
the foregoing. If made, such election will apply to all market discount bonds   
acquired by such Certificateholder on or after the first day of the first       
taxable year to which such election applies. In addition, the OID Regulations   
permit a Certificateholder to elect to accrue all interest, discount (including 
de minimis market or original issue discount) and premium in income as interest,
based on a constant yield method. If such an election were made for a REMIC     
Regular Certificate with market discount, the Certificateholder would be deemed 
to have made an election to currently include market discount in income with    
respect to all other debt instruments having market discount that such          
Certificateholder acquires during the year of the election or thereafter.       
Similarly, a Certificateholder that makes this election for a Certificate that  
is acquired at a premium is deemed to have made an election to amortize bond    
premium, as described below, with respect to all debt instruments having        
amortizable bond premium that such Certificateholder owns or acquires. The      
election to accrue interest, discount and premium on a constant yield method    
with respect to a Certificate is irrevocable.                                   

 Under a statutory de minimis exception, market discount with respect to a
REMIC Regular Certificate will be considered to be zero for purposes of Code    
Sections 1276 through 1278 if such market discount is less than 0.25% of the    
stated redemption price at maturity of such REMIC Regular Certificate           

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multiplied by the number of complete years to maturity remaining after the date 
of its purchase. In interpreting a similar de minimis rule with respect to      
original issue discount on obligations payable in installments, the OID         
Regulations refer to the weighted average maturity of obligations, and it is    
likely that the same rule will be applied in determining whether market discount
is de minimis. It appears that de minimis market discount on a REMIC Regular    
Certificate would be treated in a manner similar to original issue discount of a
de minimis amount. See 'Taxation of Holders of REMIC Regular Certificates --    
Original Issue Discount'. Such treatment would result in discount being included
in income at a slower rate than discount would be required to be included using 
the method described above. However, Treasury regulations implementing the      
market discount de minimis exception have not been issued in proposed or        
temporary form, and the precise treatment of de minimis market discount on      
obligations payable in more than one installment therefore remains uncertain.   

The 1986 Act grants authority to the Treasury Department to issue       
regulations providing for the method for accruing market discount of more than a
de minimis amount on debt instruments, the principal of which is payable in more
than one installment. Until such time as regulations are issued by the Treasury 
Department, certain rules described in the Committee Report will apply. Under   
those rules, the holder of a bond purchased with more than de minimis market    
discount may elect to accrue such market discount either on the basis of a      
constant yield method or on the basis of the appropriate proportionate method   
described below. Under the proportionate method for obligations issued with     
original issue discount, the amount of market discount that accrues during a    
period is equal to the product of (i) the total remaining market discount,      
multiplied by (ii) a fraction, the numerator of which is the original issue     
discount accruing during the period and the denominator of which is the total   
remaining original issue discount at the beginning of the period. Under the     
proportionate method for obligations issued without original issue discount, the
amount of market discount that accrues during a period is equal to the product  
of (i) the total remaining market discount, multiplied by (ii) a fraction, the  
numerator of which is the amount of stated interest paid during the accrual     
period and the denominator of which is the total amount of stated interest      
remaining to be paid at the beginning of the period. The Prepayment Assumption, 
if any, used in calculating the accrual of original issue discount is to be used
in calculating the accrual of market discount under any of the above methods.   
Because the regulations referred to in this paragraph have not been issued, it  
is not possible to predict what effect such regulations might have on the tax   
treatment of a REMIC Regular Certificate purchased at a discount in the         
secondary market.                                                               

 Further, a purchaser generally will be required to treat a portion of any
gain on sale or exchange of a REMIC Regular Certificate as ordinary income to   
the extent of the market discount accrued to the date of disposition under one  
of the foregoing methods, less any accrued market discount previously reported  
as ordinary income. Such purchaser also may be required to defer a portion of   
its interest deductions for the taxable year attributable to any indebtedness   
incurred or continued to purchase or carry such REMIC Regular Certificate. Any  
such deferred interest expense is, in general, allowed as a deduction not later 
than the year in which the related market discount income is recognized. If such
holder elects to include market discount in income currently as it accrues on   
all market discount instruments acquired by such holder in that taxable year or 
thereafter, the interest deferral rule described above will not apply.          

  A REMIC Regular Certificate purchased at a cost (not including payment for
accrued qualified stated interest) greater than its remaining stated redemption 
price at maturity will be considered to be purchased at a premium. The holder of
such a REMIC Regular Certificate may elect to amortize such premium under the   
constant yield method. The OID Regulations also permit Certificateholders to    
elect to include all interest, discount and premium in income based on a        
constant yield method, further treating the Certificateholder as having made the
election to amortize premium generally, as discussed above. The Committee Report
indicates a Congressional intent that the same rules that will apply to accrual 
of market discount on installment obligations will also apply in amortizing bond
premium under Code Section 171 on installment obligations such as the REMIC     
Regular Certificates.                                                           

3. Realized Losses                                                              

    Under Code Section 166, both corporate holders of REMIC Regular Certificates
and noncorporate holders of REMIC Regular Certificates that acquire such        
Certificates in connection with a trade or business should be allowed to deduct,
as ordinary losses, any losses sustained during a taxable year in               

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which their Certificates become wholly or partially worthless as a result of one
or more realized losses on the Mortgage Loans. However, it appears that a       
noncorporate holder that does not acquire a REMIC Regular Certificate in        
connection with a trade or business will not be entitled to deduct a loss under 
Code Section 166 until such holder's Certificate becomes wholly worthless (i.e.,
until its outstanding principal balance has been reduced to zero) and that the  
loss will be characterized as a short-term capital loss.                        

Each holder of a REMIC Regular Certificate will be required to accrue   
interest and original issue discount with respect to such Certificate without   
regard to any reduction in distributions attributable to defaults or            
delinquencies on the Mortgage Loans or the underlying assets until it can be    
established that any such reduction ultimately will not be recoverable. As a    
result, the amount of taxable income reported in any period by the holder of a  
REMIC Regular Certificate could exceed the amount of economic income actually   
realized by the holder in such period. Although the holder of a REMIC Regular   
Certificate eventually will recognize a loss or reduction in income attributable
to previously accrued and included income that, as a result of a realized loss, 
ultimately will not be realized, the law is unclear with respect to the timing  
and character of such loss or reduction in income.                              

4. Callable Class Certificates                                                  

  An entity electing to be treated as a REMIC may either itself directly, or
indirectly through the use of a trust owned by such entity, enter into a        
redemption agreement pursuant to which the counterparty will have the right to  
cause a redemption of the outstanding Certificates (as used herein, each such   
right a 'Call Right', and each such Certificate, a 'Callable Class Certificate')
beginning on the Distribution Date and subject to payment of the redemption     
price and other conditions that may be specified in the applicable Prospectus   
Supplement. See 'Description of the Certificates -- Redemption Agreement.' In   
the event the trust issues the Call Right, counsel to the Depositor will deliver
its opinion generally to the effect that, assuming compliance with all          
provisions of the related Pooling Agreement, the trust will be treated as a     
grantor trust under subpart E, part 1 of Subchapter J of the Code and, as a     
result, the REMIC will be treated as having directly issued the Call Right.     

The REMIC will be treated as (i) owning an interest in the underlying   
Mortgage Loans and (ii) writing a call option on its interest in the underlying 
Mortgage Loans, represented by the right of the holder of the Call Right to     
direct the Depositor to redeem the outstanding Certificates as described under  
'Description of the Certificates -- Redemption Agreement'.                      

  Under these circumstances, the REMIC should be considered to have acquired
its interest in the underlying Mortgage Loans for an amount equal to its initial
aggregate basis in its assets, determined as described more fully hereunder,    
plus the fair market value at the time of purchase of such REMIC's assets of the
call option the REMIC is deemed to have written, which amount the REMIC is      
deemed also to have received. Accordingly, the REMIC's basis in its interest in 
the underlying Mortgage Loans will actually be greater than the aggregate issue 
price of the REMIC Certificates it issues, resulting in less discount income or 
greater premium deductions to the REMIC than it would have recognized had the   
call option not been written. Under current federal income tax law, the REMIC   
will not be required to include immediately in income the amount of the option  
premium it is deemed to have received. However, although the treatment of these 
items is not entirely clear, it appears that as the REMIC receives principal    
payments on the underlying Mortgage Assets, and if the REMIC sells or           
distributes in kind any of the underlying Mortgage Loans, the REMIC will be     
deemed to have received (in addition to the amount of such payment, the sales   
price or the fair market value of the asset, as the case may be) an amount equal
to the corresponding portion of the payment it was deemed to receive at the time
the call option was originally written. Accordingly, the amount realized by the 
REMIC with respect to its interest in the underlying Mortgage Loans, will be    
greater than the amount of cash received by it, and over the life of the REMIC  
the entire amount of the deemed payment received when the call option was       
written will be reported by the REMIC, although not at the times that a         
corresponding amount of income would be reported based on a constant yield      
method. Investors should be aware that, subject to certain specific exceptions  
in the REMIC regulations, it is not anticipated that the REMIC will sell or     
transfer or otherwise dispose of any of the underlying Mortgage Loans except    
pursuant to an exercise of the Call Right. See 'Prohibited Transactions and     
Other Possible REMIC Taxes'. In the event that the holder of the Call Right     
chooses to effect such a redemption of the underlying Mortgage Loans, the       
transactions by                                                                 

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which the Certificates are retired and the related Trust terminated will        
constitute a 'qualified liquidation' of the REMIC within the meaning of Section 
860F(a)(4) of the Code.                                                         

  Taxation of Call Option Premium. Under current federal income tax law, the
REMIC will not be required to include immediately in income the option premium  
with respect to the Call Right that it is deemed to receive. Instead, such      
premium will be taken into account when the Call Right lapses, is exercised or  
is otherwise terminated with respect to the REMIC. As indicated above, an amount
equal to the option premium that is deemed to be received by the REMIC would be 
included in the REMIC's basis in the Mortgage Loans. The REMIC's recovery of    
such basis will not occur at the same rate as its inclusion in income of the    
option premium.                                                                 

As a grantor of an option, the REMIC must include the option premium in 
income when the option lapses, which with respect to the REMIC is no later than 
the redemption by a holder of the Call Right. Although the Call Right will not  
expire by its terms during the period in which the Certificates remain          
outstanding the Mortgage Assets to which the Call Right relates will be reduced 
over time through principal payments. Although it is not entirely clear whether 
the Call Right would thus be deemed to lapse as the Mortgage Loans are paid     
down, and if so, at what rate, the Depositor intends to report income to the    
REMIC based on the assumption that the Call Right lapses, and the related       
premium is recognized by the REMIC, proportionately as principal is paid on the 
Mortgage Loans (as prepayments prior to the date on which the Call Right may    
first be exercised or as scheduled principal payments or prepayments after the  
first date on which the Call Right may be exercised). There is no assurance that
the IRS would agree with this method of reporting income from the lapse of the  
Call Right, and furthermore, it should be noted that the IRS currently is       
examining the rules regarding the taxation of option premiums.                  

 If the Call Right is exercised, the REMIC will add an amount equal to the
unamortized portion of the option premium to the amount realized from the sale  
of the underlying Mortgage Loans.                                               

  If the REMIC transfers one of the underlying Mortgage Loans, such transfer
will be treated as a 'closing transaction' with respect to the option the REMIC 
is deemed to have written. Accordingly, the REMIC will recognize gain or loss   
equal to the difference between the unamortized amount of option premium and the
amount the REMIC is deemed to pay, under the rules discussed above, to be       
relieved from its obligations under the option. However, as discussed above,    
subject to certain specified exceptions (including in connection with the       
issuance of the Call Right), it is not anticipated that the REMIC will transfer 
any of the underlying Mortgage Loans. See 'Prohibited Transactions and Other    
Possible REMIC Taxes'.                                                          

    Certificateholders are urged to consult their tax advisors before purchasing
an interest in any Callable Class Certificate.                                  

TAXATION OF OWNERS OF REMIC RESIDUAL CERTIFICATES                               

1. General                                                                      

  An owner of a REMIC Residual Certificate ('Residual Owner') generally will
be required to report its daily portion of the taxable income or, subject to the
limitation described below in ' -- Taxation of Owners of REMIC Residual         
Certificates -- Basis Rules and Distributions', the net loss of the REMIC       
Mortgage Pool for each day during a calendar quarter that the Residual Owner    
owned such REMIC Residual Certificate. For this purpose, the daily portion will 
be determined by allocating to each day in the calendar quarter, using a 30 days
per month/90 days per quarter/360 days per year counting convention (unless     
otherwise disclosed in the applicable Prospectus Supplement), its ratable       
portion of the taxable income or net loss of the REMIC Mortgage Pool for such   
quarter, and by allocating the daily portions among the Residual Owners (on such
day) in accordance with their percentage of ownership interests on such day. Any
amount included in the gross income or allowed as a loss of any Residual Owner  
by virtue of this paragraph will be treated as ordinary income or loss.         
Purchasers of REMIC Residual Certificates should be aware that taxable income   
from such Certificates could exceed cash distributions thereon in any taxable   
year. For example, if Mortgage Loans are acquired by a REMIC at a discount, then
the holder of a residual interest may recognize income without corresponding    
cash distributions. This result could occur because a payment produces          
recognition of discount on the Mortgage                                         

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Loan while the payment could be used in whole or in part to make principal      
payments on REMIC Regular Certificates issued without substantial discount.     
Taxable income may also be greater in earlier years as a result of the fact that
interest expense deductions, expressed as a percentage of the outstanding       
principal amount of the REMIC Regular Certificates, will increase over time as  
the lower yielding sequences of Certificates are paid, whereas interest income  
with respect to any given fixed rate Mortgage Loan will remain constant over    
time as a percentage of the outstanding principal amount of that loan.          

Any payments received by a holder of a REMIC Residual Certificate in    
connection with the acquisition of such Certificate will be taken into account  
in determining the income of such holder for federal income tax purposes.       
Although the timing of such income is unclear under current law and certain     
court cases suggest that, in the absence of other authority, any such payment   
would be includible in income immediately upon its receipt, the IRS has issued  
proposed regulations that, if adopted as final regulations, would require such  
payment to be included in income over time according to an amortization schedule
that reasonably reflects the costs and benefits of holding the REMIC Residual   
Certificate over its expected life. The proposed regulations also would provide 
two more specific methods that would be accepted as meeting the general test set
forth above for determining the timing and amount of income inclusion. One      
generally follows the method of inclusion used by the taxpayer for GAAP         
purposes, but not over a period shorter than the period over which the REMIC is 
expected to generate income. The other calls for ratable inclusion over the     
remaining anticipated weighted average life of the REMIC as of the time the     
REMIC Residual Certificate is transferred to the taxpayer. Because of the       
uncertainty concerning the treatment of such payments, holders of REMIC Residual
Certificates should consult their tax advisors concerning the treatment of such 
payments for income tax purposes.                                               

 If so specified in the applicable Prospectus Supplement for a Series, the
underlying Mortgage Loans may be subject to redemption at the direction of the  
holder of certain redemption right. As a direct owner in the underlying Mortgage
Loans for federal income tax purposes, the REMIC will also be treated as having 
written the call option on such underlying Mortgage Loans. See 'Callable Class  
Certificates'.                                                                  

2. Taxable Income or Net Loss of the REMIC                                      

The taxable income or net loss of the REMIC Mortgage Pool will reflect a
netting of income from the Mortgage Loans, any cancellation of indebtedness     
income due to the allocation of Realized Losses to REMIC Regular Certificates,  
and deductions and losses allowed to the REMIC Mortgage Pool. Such taxable      
income or net loss for a given calendar quarter will be determined in the same  
manner as for an individual having the calendar year as his taxable year and    
using the accrual method of accounting, with certain modifications. The first   
modification is that a deduction will be allowed for accruals of interest       
(including original issue discount) on the REMIC Regular Certificates. Second,  
market discount equal to the excess of any Mortgage Loan's adjusted issue price 
(as determined under 'Taxation of Owners of REMIC Regular Certificates -- Market
Discount and Premium') over its fair market value at the time of their transfer 
to the REMIC Mortgage Pool generally will be included in income as it accrues,  
based on a constant yield and on the Prepayment Assumption. For this purpose,   
the Company intends to treat the fair market value of the Mortgage Loans as     
being equal to the aggregate issue prices of the REMIC Regular Certificates and 
REMIC Residual Certificates; if one or more classes of REMIC Regular            
Certificates or REMIC Residual Certificates are retained by the Company, it will
estimate the value of such retained interests in order to determine the fair    
market value of the Mortgage Loans for this purpose. Third, no item of income,  
gain, loss or deduction allocable to a prohibited transaction (see              
' -- Prohibited Transactions and Other Possible REMIC Taxes', below) will be    
taken into account. Fourth, the REMIC Mortgage Pool generally may not deduct any
item that would not be allowed in calculating the taxable income of a           
partnership by virtue of Code Section 703(a)(2). Fifth, the REMIC Regulations   
provide that the limitation on miscellaneous itemized deductions imposed on     
individuals by Code Section 67 will not be applied at the Mortgage Pool level to
the servicing fees paid to the Master Servicer or sub-servicers, if any. (See,  
however, ' -- Pass-Through of Servicing Fees', below.) If the deductions allowed
to the REMIC Mortgage Pool exceed its gross income for a calendar quarter, such 
excess will be the net loss for the REMIC Mortgage Pool for that calendar       
quarter.                                                                        

3. Basis Rules and Distributions                                                

 Any distribution by a REMIC Mortgage Pool to a Residual Owner will not be
included in the gross income of such Residual Owner to the extent it does not   
exceed the adjusted basis of such Residual Owner's interest in a REMIC Residual 
Certificate. Such distribution will reduce the adjusted basis of such           

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interest, but not below zero. To the extent a distribution exceeds the adjusted 
basis of the REMIC Residual Certificate, it will be treated as gain from the    
sale of the REMIC Residual Certificate. (See ' -- Sales of REMIC Certificates', 
below.) The adjusted basis of a REMIC Residual Certificate is equal to the      
amount paid for such REMIC Residual Certificate, increased by amounts included  
in the income of the Residual Owner (See ' -- Taxation of Owners of REMIC       
Residual Certificates -- Daily Portions', above) and decreased by distributions 
and by net losses taken into account with respect to such interest.             

 A Residual Owner is not allowed to take into account any net loss for any
calendar quarter to the extent such net loss exceeds such Residual Owner's      
adjusted basis in its REMIC Residual Certificate as of the close of such        
calendar quarter (determined without regard to such net loss). Any loss         
disallowed by reason of this limitation may be carried forward indefinitely to  
future calendar quarters and, subject to the same limitation, may be used only  
to offset income from the REMIC Residual Certificate.                           

 The effect of these basis and distribution rules is that a Residual Owner
may not amortize its basis in a REMIC Residual Certificate, but may only recover
its basis through distributions, through the deduction of any net losses of the 
REMIC Mortgage Pool or upon the sale of its REMIC Residual Certificate (See     
' -- Sales of REMIC Certificates', below). The residual holder does, however,   
receive reduced taxable income over the life of the REMIC, because the REMIC's  
basis in the underlying REMIC Mortgage Pool includes the fair market value of   
the REMIC Regular Certificates and REMIC Residual Certificates.                 

4. Excess Inclusions                                                            

Any 'excess inclusions' with respect to a REMIC Residual Certificate are
subject to certain special tax rules. With respect to a Residual Owner, the     
excess inclusion for any calendar quarter is defined as the excess (if any) of  
the daily portions of taxable income over the sum of the 'daily accruals' for   
each day during such quarter that such REMIC Residual Certificate was held by   
such Residual Owner. The daily accruals are determined by allocating to each day
during a calendar quarter its ratable portion of the product of the 'adjusted   
issue price' of the REMIC Residual Certificate at the beginning of the calendar 
quarter and 120 percent of the long-term 'applicable federal rate' (generally,  
an average of current yields on Treasury securities of comparable maturity) (the
'AFR') in effect at the time of issuance of the REMIC Residual Certificate. For 
this purpose, the adjusted issue price of a REMIC Residual Certificate as of the
beginning of any calendar quarter is the issue price of the REMIC Residual      
Certificate, increased by the amount of daily accruals for all prior quarters   
and decreased by any distributions made with respect to such REMIC Residual     
Certificate before the beginning of such quarter. The issue price of a REMIC    
Residual Certificate is the initial offering price to the public (excluding bond
houses and brokers) at which a substantial amount of the REMIC Residual         
Certificates were sold.                                                         

An excess inclusion cannot be offset by deductions, losses or loss      
carryovers from other activities. For Residual Owners that are subject to tax on
unrelated business taxable income (as defined in Code Section 511), an excess   
inclusion of such Residual Owner is treated as unrelated business taxable       
income. For Residual Owners that are nonresident alien individuals or foreign   
corporations generally subject to United States 30% withholding tax, even if    
interest paid to such Residual Owners is generally eligible for exemptions from 
such tax, an excess inclusion will be subject to such tax and no tax treaty rate
reduction or exemption may be claimed with respect thereto. See ' -- Foreign    
Investors in REMIC Certificates'. Section 860E(a)(4) of the Code provides three 
rules for determining the effect on excess inclusions on the alternative minimum
taxable income of a residual holder. First, alternative minimum taxable income  
for a residual holder is determined without regard to the special rule that     
taxable income cannot be less than excess inclusions. Second, a residual        
holder's alternative minimum taxable income for a tax year cannot be less than  
excess inclusions for the year. Third, the amount of any alternative minimum tax
net operating loss deductions must be computed without regard to any excess     
inclusions.                                                                     

Although it has not done so, the Treasury also has authority to issue   
regulations that, if REMIC Residual Certificates are found in the aggregate not 
to have 'significant value', would treat as excess inclusions with respect to   
such REMIC Residual Certificates the entire daily portion of taxable income for 
such REMIC Residual Certificates. In order to have significant value, the REMIC 
Residual Certificates must have an aggregate issue price, at issuance, at least 
equal to two percent of the aggregate issue prices of all of the related REMIC  
Regular and Residual Certificates. In addition, the anticipated weighted average
life of the REMIC Residual Certificates must equal or exceed 20 percent of the  
anticipated weighted average life of the REMIC, based on the Prepayment         
Assumption and on any required or                                               

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permitted clean up calls or required liquidation provided for in the REMIC's    
organizational documents. Each Prospectus Supplement pursuant to which REMIC    
Residual Certificates are offered will state whether such REMIC Residual        
Certificates will have, or may be regarded as having, 'significant value' under 
the REMIC Regulations; provided, however, that any disclosure that a REMIC      
Residual Certificate will have 'significant value' will be based upon certain   
assumptions, and the Company will make no representation that a REMIC Residual  
Certificate will have 'significant value' for purposes of the above described   
rules or that a Residual Owner will receive distributions of amounts calculated 
pursuant to those assumptions.                                                  

In the case of any REMIC Residual Certificates held by a real estate    
investment trust, the aggregate excess inclusions with respect to such REMIC    
Residual Certificates, reduced (but not below zero) by the real estate          
investment trust taxable income (within the meaning of Code Section 857(b)(2),  
excluding any net capital gain), will be allocated among the shareholders of    
such trust in proportion to the dividends received by such shareholders from    
such trust, and any amount so allocated will be treated as an excess inclusion  
with respect to a REMIC Residual Certificate as if held directly by such        
shareholder.                                                                    

5. Noneconomic REMIC Residual Certificates                                      

Under the REMIC Regulations, transfers of 'noneconomic' REMIC Residual  
Certificates will be disregarded for all federal income tax purposes if 'a      
significant purpose of the transfer was to enable the transferor to impede the  
assessment or collection of tax'. If such transfer is disregarded, the purported
transferor will continue to remain liable for any taxes due with respect to the 
income on such 'noneconomic' REMIC Residual Certificate. The REMIC Regulations  
provide that a REMIC Residual Certificate will be considered a noneconomic      
residual interest unless, at the time of its transfer and based on the          
Prepayment Assumption and any required or permitted clean up calls or required  
liquidation provided for in the REMIC's organizational documents, (1) the       
present value of the expected future distributions (discounted using the AFR) on
the REMIC Residual Certificate equals at least the present value of the expected
tax on the anticipated excess inclusions, and (2) the transferor reasonably     
expects that the transferee will receive distributions with respect to the REMIC
Residual Certificate at or after the time the taxes accrue on the anticipated   
excess inclusions in an amount sufficient to satisfy the accrued taxes.         
Accordingly, all transfers of REMIC Residual Certificates that may constitute   
noneconomic residual interests will be subject to certain restrictions under the
terms of the related Pooling Agreement that are intended to reduce the          
possibility of any such transfer being disregarded. Such restrictions will      
require each party to a transfer to provide an affidavit that no purpose of such
transfer is to impede the assessment or collection of tax, including certain    
representations as to the financial condition of the prospective transferee. The
Internal Revenue Service has issued final REMIC regulations that add to the     
conditions necessary to assure that a transfer of a noneconomic residual        
interest would be respected. The additional conditions require that the         
transferee represent that it will not cause the income 'to be attributable to a 
foreign permanent establishment or fixed base (within the meaning of an         
applicable income tax treaty) of the transferee or another U.S. taxpayer' and   
either (i) the amount received by the transferee be no less on a present value  
basis than the present value of the next tax detriment attributable to holding  
the residual interest reduced by the present value of the projected payments to 
be received on the residual interest or (ii) the transfer is to a domestic      
taxable corporation with specified large amounts of gross and net assets and    
that meets certain other requirements where agreement is made that all future   
transfers will be to taxable domestic corporations in transactions that qualify 
for the same 'safe harbor' provision. Eligibility for the safe harbor requires, 
among other things, that the facts and circumstances known to the transferor at 
the time of transfer not indicate to a reasonable person that the taxes with    
respect to the residual interest will not be paid, with an unreasonably low cost
for the transfer specifically mentioned as negating eligibility. The regulations
are effective as of July 19, 2002, although most of their provisions apply to   
transfers of residual interests occurring after February 4, 2000. Prior to      
purchasing a REMIC Residual Certificate, prospective purchasers should consider 
the possibility that a purported transfer of such REMIC Residual Certificate by 
such a purchaser to another purchaser at some future date may be disregarded in 
accordance with the above-described rules, which would result in the retention  
of tax liability by such purchaser. The applicable Prospectus Supplement will   
disclose whether offered REMIC Residual Certificates may be considered          
'noneconomic' residual interests under the REMIC Regulations; provided, however,
that any disclosure that a REMIC Residual Certificate will or will not be       
considered 'noneconomic' will be based upon certain assumptions, and the Company
will make no representation that a REMIC Residual Certificate will not be       
considered 'noneconomic' for purposes of the above-described rules or that a    
REMIC Residual Owner will receive distributions calculated pursuant to such     

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assumptions. See 'Foreign Investors in REMIC Certificates' below for additional 
restrictions applicable to transfers of certain REMIC Residual Certificates to  
foreign persons.                                                                

6. Tax-Exempt Investors                                                         

  Generally, tax exempt organizations that are not subject to Federal income
taxation on 'unrelated business taxable income' pursuant to Code Section 511 are
treated as 'disqualified organizations' under provisions of the 1988 Act. Under 
provisions of the Pooling Agreement, such organizations generally are prohibited
from owning Residual Certificates. For Residual Owners that are subject to tax  
on unrelated business taxable income (as defined in Code Section 511), an excess
inclusion of such Residual Owner is treated as unrelated business taxable       
income. See ' -- Sales of REMIC Certificates'.                                  

7. Real Estate Investment Trusts                                                

If the applicable Prospectus Supplement so provides, a Mortgage Pool may
hold Mortgage Loans bearing interest based wholly or partially on Mortgagor     
profits, Mortgaged Property appreciation, or similar contingencies. Such        
interest, if earned directly by a real estate investment trust ('REIT'), would  
be subject to the limitations of Code Sections 856 (f) and 856 (j). Treasury    
regulations treat a REIT holding a REMIC Residual Certificate for a principal   
purpose of avoiding such Code provisions as receiving directly the income of the
REMIC Mortgage Pool, hence potentially jeopardizing its qualification for       
taxation as a REIT and exposing such income to taxation as a prohibited         
transaction at a 100 percent rate.                                              

8. Mark-to-Market Rules                                                         

 Treasury regulations provide that any REMIC Residual Certificate acquired
after January 3, 1995 will not be treated as a security and therefore generally 
may not be marked-to-market.                                                    

SALES OF REMIC CERTIFICATES                                                     

    If a REMIC Certificate is sold, the seller will recognize gain or loss equal
to the difference between the amount realized on the sale and its adjusted basis
in the REMIC Certificate. The adjusted basis of a REMIC Regular Certificate     
generally will equal the cost of such REMIC Regular Certificate to the seller,  
increased by any original issue discount or market discount included in the     
seller's gross income with respect to such REMIC Regular Certificate and reduced
by premium amortization deductions and distributions previously received by the 
seller of amounts included in the stated redemption price at maturity of such   
REMIC Regular Certificate. The adjusted basis of a REMIC Residual Certificate   
will be determined as described under ' -- Taxation of Owners of REMIC Residual 
Certificates -- Basis Rules and Distributions', above. Gain from the disposition
of a REMIC Regular Certificate that might otherwise be treated as a capital gain
will be treated as ordinary income to the extent that such gain does not exceed 
the excess, if any, of (i) the amount that would have been includible in such   
holder's income had income accrued at a rate equal to 110% of the AFR as of the 
date of purchase over (ii) the amount actually includible in such holder's      
income. Except as otherwise provided under ' -- Taxation of Owners of REMIC     
Regular Certificates -- Market Discount and Premium' and under Code Section     
582(c), any additional gain or any loss on the sale or exchange of a REMIC      
Certificate will be capital gain or loss, provided such REMIC Certificate is    
held as a capital asset (generally, property held for investment) within the    
meaning of Code Section 1221. The distinction between a capital gain or loss and
ordinary income or loss is also relevant for other purposes, including          
limitations on the use of capital losses to offset ordinary income.             

A portion of any gain from the sale of a REMIC Regular Certificate that 
might otherwise be capital gain may be treated as ordinary income to the extent 
that such Certificate is held as part of a 'conversion transaction' within the  
meaning of Code Section 1258. A conversion transaction generally is one in which
the taxpayer has taken two or more positions in Certificates or similar property
that reduce or eliminate market risk, if substantially all of the taxpayer's    
return is attributable to the time value of the taxpayer's net investment in    
such transaction. The amount of gain so realized in a conversion transaction    
that is recharacterized as ordinary income generally will not exceed the amount 
of interest that would have accrued on the taxpayer's net investment at 120% of 
the AFR at the time the taxpayer enters into the                                

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conversion transaction, subject to appropriate reduction for prior inclusion of 
interest and other ordinary income items from the transaction.                  

    A taxpayer may elect to have net capital gain taxed at ordinary income rates
rather than capital gains rates in order to include such net capital gain in    
total net investment income for that taxable year, for purposes of the          
limitation on the deduction of interest on indebtedness incurred to purchase or 
carry property held for investment to a taxpayer's net investment income.       

    The Omnibus Budget Reconciliation Act of 1993 (the 'Budget Act') revised the
rules for deducting interest on indebtedness allocable to property held for     
investment. Generally, deductions for such interest are limited to a taxpayer's 
net investment income for each taxable year. As amended by the Budget Act, net  
investment income for each taxable year includes net capital gain attributable  
to the disposition of investment property only if the taxpayer elects to have   
such net capital gain taxed at ordinary income rates rather than capital gains  
rates.                                                                          

  If a Residual Owner sells a REMIC Residual Certificate at a loss, the loss
will not be recognized if, within six months before or after the sale of the    
REMIC Residual Certificate, such Residual Owner purchases another residual      
interest in any REMIC or any interest in a taxable mortgage pool (as defined in 
Code Section 7701(i)) comparable to a residual interest in a REMIC. Such        
disallowed loss will be allowed upon the sale of the other residual interest (or
comparable interest) if the rule referred to in the preceding sentence does not 
apply to that sale. While the Committee Report states that this rule may be     
modified by Treasury regulations, the REMIC Regulations do not address this     
issue and it is not clear whether any such modification will in fact be         
implemented or, if implemented, what the precise nature or effective date of it 
would be.                                                                       

    The 1988 Act makes transfers of a residual interest to certain 'disqualified
organizations' subject to an additional tax on the transferor in an amount equal
to the maximum corporate tax rate applied to the present value of the total     
anticipated excess inclusions (discounted using the applicable Federal rate)    
with respect to such residual interest for the periods after the transfer. For  
this purpose, 'disqualified organizations' includes the United States, any state
or political subdivision of a state, any foreign government or international    
organization or any agency or instrumentality of any of the foregoing; any tax- 
exempt entity (other than a Code Section 521 cooperative) which is not subject  
to the tax on unrelated business income; and any rural electrical and telephone 
cooperative. The anticipated excess inclusions must be determined as of the date
that the REMIC Residual Certificate is transferred and must be based on events  
that have occurred up to the time of such transfer, the Prepayment Assumption,  
and any required or permitted clean up calls or required liquidation provided   
for in the REMIC's organizational documents. The tax generally is imposed on the
transferor of the REMIC Residual Certificate, except that it is imposed on an   
agent for a disqualified organization if the transfer occurs through such agent.
The Pooling Agreement requires, as a prerequisite to any transfer of a Residual 
Certificate, the delivery to the Trustee of an affidavit of the transferee to   
the effect that it is not a disqualified organization and contains other        
provisions designed to render any attempted transfer of a Residual Certificate  
to a disqualified organization void. For purposes of the affidavit, the Pooling 
Agreement also treats an 'electing large partnership' as defined in Section     
775(a) of the Code as if it were a 'disqualified organization.'                 

    In addition, if a 'pass-through entity' includes in income excess inclusions
with respect to a REMIC Residual Certificate, and a disqualified organization is
the record holder of an interest in such entity, then a tax will be imposed on  
such entity equal to the product of (i) the amount of excess inclusions on the  
REMIC Residual Certificate that are allocable to the interest in the            
pass-through entity held by such disqualified organization and (ii) the highest 
marginal federal income tax rate imposed on corporations. A pass-through entity 
will not be subject to this tax for any period, however, if the record holder of
an interest in such entity furnishes to such entity (i) such holder's social    
security number and a statement under penalties of perjury that such social     
security number is that of the record holder or (ii) a statement under penalties
of perjury that such record holder is not a disqualified organization. For these
purposes, a 'pass-through entity' means any regulated investment company, real  
estate investment trust, trust, partnership or certain other entities described 
in Section 860E(e)(6) of the Code. In addition, a person holding an interest in 
a pass-through entity as a nominee for another person shall, with respect to    
such interest, be treated as a pass-through entity.                             

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PASS-THROUGH OF SERVICING FEES                                                  

The general rule is that Residual Certificateholders take into account  
taxable income or net loss of the related REMIC Mortgage Pool. Under that rule, 
servicing compensation of the Company and the subservicers (if any) would be    
allocated to the holders of the REMIC Residual Certificates, and therefore would
not affect the income or deductions of holders of REMIC Regular Certificates.   
However, in the case of a 'single-class REMIC', such expenses and an equivalent 
amount of additional gross income will be allocated among all holders of REMIC  
Regular Certificates and REMIC Residual Certificates for purposes of the        
limitations on the deductibility of certain miscellaneous itemized deductions by
individuals contained in Code Sections 56(b)(1) and 67. Generally, any holder of
a REMIC Certificate who is an individual, estate or trust will be able to deduct
such expenses in determining regular tax liability only to the extent that such 
expenses together with certain other miscellaneous itemized deductions of such  
individual, estate or trust exceed 2% of adjusted gross income; such a holder   
may not deduct such expenses to any extent in determining liability for         
alternative minimum tax. Accordingly, REMIC Residual Certificates, and REMIC    
Regular Certificates receiving an allocation of servicing compensation, may not 
be appropriate investments for individuals, estates or trusts, and such persons 
should carefully consult with their own tax advisors regarding the advisability 
of an investment in such Certificates.                                          

A 'single-class REMIC' is a REMIC that either (i) would be treated as a 
pass-through trust under the provisions of Treasury Regulation Section          
301.7701-4(c) in the absence of a REMIC election, or (ii) is substantially      
similar to such a pass-through trust and is structured with the principal       
purpose of avoiding the allocation of investment expenses to holders of REMIC   
Regular Certificates. Unless otherwise stated in the related Prospectus         
Supplement, the Company intends to treat a REMIC Mortgage Pool as other than a  
'single-class REMIC', consequently allocating servicing compensation expenses   
and related income amounts entirely to REMIC Residual Certificates and in no    
part to REMIC Regular Certificates.                                             

PROHIBITED TRANSACTIONS AND OTHER POSSIBLE REMIC TAXES                          

  The Code imposes a tax on REMIC Mortgage Pools equal to 100 percent of the
net income derived from 'prohibited transactions'. In general, a prohibited     
transaction means the disposition of a Mortgage Loan other than pursuant to     
certain specified exceptions, the receipt of income from a source other than a  
Mortgage Loan or certain other permitted investments, the receipt of            
compensation for services, or gain from the disposition of an asset purchased   
with the payments on the Mortgage Loans for temporary investment pending        
distribution on the REMIC Certificates. The Code also imposes a 100 percent tax 
on the value of any contribution of assets to the REMIC after the 'start-up day'
(the day on which the regular and residual interests are issued), other than    
pursuant to specified exceptions, and subjects 'net income from foreclosure     
property' to tax at the highest corporate rate. It is not anticipated that a    
REMIC Mortgage Pool will engage in any such transactions or receive any such    
income.                                                                         

TERMINATION OF A REMIC                                                          

 In general, no special tax consequences will apply to a holder of a REMIC
Regular Certificate upon the termination of the REMIC Mortgage Pool by virtue of
the final payment or liquidation of the last Mortgage Loan remaining in the     
REMIC Mortgage Pool. If a Residual Owner's adjusted basis in its REMIC Residual 
Certificate at the time such termination occurs exceeds the amount of cash      
distributed to such Residual Owner in liquidation of its interest, then,        
although the matter is not entirely free from doubt, it appears that the        
Residual Owner would be entitled to a loss (which would be a capital loss) equal
to the amount of such excess.                                                   

REPORTING AND OTHER ADMINISTRATIVE MATTERS OF REMICS                            

 Reporting of interest income, including any original issue discount, with
respect to REMIC Regular Certificates is required annually, and may be required 
more frequently under Treasury regulations. In addition to those holders of     
REMIC Regular Certificates to whom information reporting generally applies,     
certain holders of REMIC Regular Certificates who are generally exempt from     
information reporting on debt instruments, such as corporations, banks,         
registered securities or commodities brokers, real estate investment trusts,    
registered investment companies, common trust funds, charitable remainder       
annuity trusts                                                                  

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and unitrusts, will be provided interest and original issue discount income     
information and the information set forth in the following paragraph upon       
request in accordance with the requirements of the Treasury regulations. The    
information must be provided by the later of 30 days after the end of the       
quarter for which the information was requested, or two weeks after the receipt 
of the request. The REMIC Mortgage Pool must also comply with rules requiring it
to report to the Treasury Department the amount of original issue discount and  
the issue date for each REMIC Certificate issued at more than a de minimis      
discount.                                                                       

  The REMIC Regular Certificate information reports must include a statement
of the 'adjusted issue price' of the REMIC Regular Certificate at the beginning 
of each accrual period. In addition, the reports must include information       
necessary to compute the accrual of any market discount that may arise upon     
secondary trading of REMIC Regular Certificates. Because exact computation of   
the accrual of market discount on a constant yield method would require         
information relating to the holder's purchase price which the REMIC Mortgage    
Pool may not have, it appears that this provision will only require information 
pertaining to the appropriate proportionate method of accruing market discount. 

   The responsibility for complying with the foregoing reporting rules will be
borne by the Company.                                                           

 For purposes of the administrative provisions of the Code, REMIC Mortgage
Pools will be treated as partnerships and the holders of Residual Certificates  
will be treated as partners. Unless otherwise stated in the applicable          
Prospectus Supplement, the Company will file federal income tax information     
returns on behalf of the related REMIC Mortgage Pool, and will be designated as 
agent for, and will act on behalf of the 'tax matters person' with respect to   
the REMIC Mortgage Pool in all respects.                                        

 As agent for the tax matters person, the Company will, subject to certain
notice requirements and various restrictions and limitations, generally have the
authority to act on behalf of the REMIC and the Residual Owners in connection   
with the administrative and judicial review of items of income, deduction, gain 
or loss of the REMIC Mortgage Pool, as well as the REMIC Mortgage Pool's        
classification. Residual Owners will generally be required to report such REMIC 
Mortgage Pool items consistently with their treatment on the REMIC Mortgage     
Pool's federal income tax information return and may in some circumstances be   
bound by a settlement agreement between the Master Servicer, as agent for the   
tax matters person, and the IRS concerning any such REMIC Mortgage Pool item.   
Adjustments made to the REMIC Mortgage Pool tax return may require a Residual   
Owner to make corresponding adjustments on its return, and an audit of the REMIC
Mortgage Pool's tax return, or the adjustments resulting from such an audit,    
could result in an audit of a Residual Owner's return.                          

BACKUP WITHHOLDING WITH RESPECT TO REMIC CERTIFICATES                           

    Payments of interest and principal on REMIC Regular Certificates, as well as
payments of proceeds from the sale of REMIC Certificates, may be subject to the 
'backup withholding tax' under Section 3406 of the Code if recipients of such   
payments fail to furnish to the payor certain information, including their      
taxpayer identification numbers, or otherwise fail to establish an exemption    
from such tax. Any amounts deducted and withheld from a distribution to a       
recipient would be allowed as a credit against such recipient's federal income  
tax. Furthermore, certain penalties may be imposed by the IRS on a recipient of 
payments that is required to supply information but that does not do so in the  
proper manner.                                                                  

FOREIGN INVESTORS IN REMIC CERTIFICATES                                         

1. REMIC Regular Certificates                                                   

    Except as qualified below, payments made on a REMIC Regular Certificate to a
REMIC Regular Certificateholder that is not a U.S. Person, as hereinafter       
defined (a 'Non-U.S. Person'), or to a person acting on behalf of such a        
Certificateholder, generally will be exempt from U.S. federal income and        
withholding taxes, provided (a)the holder of the Certificate is not subject to  
U.S. tax as a result of a connection to the United States other than ownership  
of such Certificate, (b) the holder of such Certificate signs and delivers a    
statement under penalties of perjury that certifies that such holder is a       
Non-U.S. Person, and provides the name and address of such holder (this         
statement is generally made on IRS Form W-8BEN and must be updated whenever     
required information has changed or within 3 calendar years after the statement 
is first delivered), and (c) the last U.S. Person (or in certain circumstances a

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qualified withholding agent that is not a U.S. Person) in the chain of payment  
to the holder received such statement from such holder or a financial           
institution holding on its behalf and does not have actual knowledge that such  
statement is false. If the holder does not qualify for exemption, distributions 
of interest, including distributions in respect of accrued original issue       
discount, to such holder may be subject to a withholding tax rate of 30 percent,
subject to reduction under any applicable tax treaty.                           

Special rules apply to partnerships, estates and trusts, and in certain 
circumstances certifications as to foreign status and other matters may be      
required to be provided by partners and beneficiaries thereof.                  

  'U.S. Person' means (i) a citizen or resident of the United States, (ii) a
corporation or partnership (including any entity treated as a partnership or    
corporation for federal income tax purposes) created or organized in or under   
the laws of the United States, any state or the District of Columbia, or (iii)  
an estate or trust that is subject to U.S. federal income tax regardless of the 
source of its income.                                                           

Holders of REMIC Regular Certificates should be aware that the IRS might
take the position that exemption from U.S. withholding taxes does not apply to  
such a holder that also directly or indirectly owns 10 percent or more of the   
REMIC Residual Certificates of a particular Series of Certificates. Further, the
foregoing rules will not apply to exempt a United States shareholder of a       
controlled foreign corporation from taxation on such United States shareholder's
allocable portion of the interest or original issue discount income earned by   
such controlled foreign corporation.                                            

2. REMIC Residual Certificates                                                  

    Amounts paid to a Residual Owner that is a Non-U.S. Person generally will be
treated as interest for purposes of applying the withholding tax on Non-U.S.    
Persons with respect to income on its REMIC Residual Certificate. However, it is
unclear whether distributions on REMIC Residual Certificates will be eligible   
for the general exemption from withholding tax that applies to REMIC Regular    
Certificates as described above. Treasury regulations provide that, for purposes
of the portfolio interest exception, payments to the foreign owner of a REMIC   
Residual Certificate are to be considered paid on the obligations held by the   
REMIC, rather than on the Certificate itself. Such payments would thus only     
qualify for the portfolio interest exception if the underlying obligations held 
by the REMIC would so qualify. Such withholding tax generally would be imposed  
at a rate of 30 percent but would be subject to reduction under any tax treaty  
applicable to the Residual Owner. However, there is no exemption from           
withholding tax nor may the rate of such tax be reduced, under a tax treaty or  
otherwise, with respect to any distribution of income that is an excess         
inclusion. See ' -- Taxation of Owners of REMIC Residual Certificates -- Excess 
Inclusions'.                                                                    

    Certain restrictions relating to transfers of REMIC Residual Certificates to
and by investors who are not U.S. Persons are also imposed by the REMIC         
Regulations. First, transfers of REMIC Residual Certificates to Non-U.S. Persons
that have 'tax avoidance potential' are disregarded for all federal income tax  
purposes. If such transfer is disregarded, the purported transferor of such a   
REMIC Residual Certificate to a Non-U.S. Person would continue to remain liable 
for any taxes due with respect to the income on such REMIC Residual Certificate.
A REMIC Residual Certificate has tax avoidance potential unless, at the time of 
the transfer, the transferor reasonably expects that the REMIC will distribute  
to the transferee amounts that will equal at least 30 percent of each excess    
inclusion, and that such amounts will be distributed at or after the time at    
which the excess inclusion accrues and not later than the close of the calendar 
year following the calendar year of accrual. This rule does not apply to        
transfers if the income from the REMIC Residual Certificate is taxed in the     
hands of the transferee as income effectively connected with the conduct of a   
U.S. trade or business. Second, if a Non-U.S. Person transfers a REMIC Residual 
Certificate to a U.S. Person, and the transfer has the effect of allowing the   
transferor to avoid tax on accrued excess inclusions, that transfer is          
disregarded for all federal income tax purposes and the purported Non-U.S.      
Person transferor continues to be treated as the owner of the REMIC Residual    
Certificate. Thus, the REMIC's liability to withhold 30 percent of the accrued  
excess inclusions is not terminated even though the REMIC Residual Certificate  
is no longer held by a Non-U.S. Person.                                         

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NEW WITHHOLDING REGULATIONS                                                     

The Treasury Department has issued new final regulations which revise   
procedures for complying with, or obtaining exemptions under, the withholding,  
backup withholding and information reporting rules described above. Prospective 
investors are urged to consult their tax advisors regarding the procedures for  
obtaining an exemption from withholding under the new regulations.              

TAX RETURN DISCLOSURE AND INVESTOR LIST REQUIREMENTS                            

Recent Treasury pronouncements directed at abusive tax shelter activity 
appear to apply to transactions not conventionally regarded as tax shelters.    
Temporary and proposed regulations require taxpayers to report certain          
disclosures on IRS form 8886 if they participate in a 'reportable transaction.' 
Organizers and sellers of the transaction are required to maintain records      
including investor lists containing identifying information and to furnish those
records to the IRS upon demand. A transaction may be a 'reportable transaction' 
based upon any of several indicia, including the existence of book-tax          
differences common to financial transactions, one or more of which may be       
present with respect to your investment in the Certificates. There are pending  
in the Congress legislative proposals that, if enacted, would impose significant
penalties for failure to comply with these disclosure requirements. Investors   
should consult their own tax advisers concerning any possible disclosure        
obligation with respect to their investment, and should be aware that the       
Company and other participants in the transaction intend to comply with such    
disclosure and investor list maintenance requirements as they determine apply to
them with respect to this transaction.                                          

STATE AND LOCAL TAXATION                                                        

 Many states do not automatically conform to changes in the federal income
tax laws. Consequently, a REMIC Mortgage Pool which would not qualify as a fixed
investment trust for federal income tax purposes may be characterized as a      
corporation, a partnership, or some other entity for purposes of state income   
tax law. Such characterization could result in entity level income or franchise 
taxation of a REMIC Mortgage Pool formed in, owning mortgages or property in, or
having servicing activity performed in a state without conforming REMIC         
provisions in its income or franchise tax law. Further, REMIC Regular           
Certificateholders resident in nonconforming states may have their ownership of 
REMIC Regular Certificates characterized as an interest other than debt of the  
REMIC such as stock or a partnership interest. Investors are advised to consult 
their tax advisors concerning the state and local income tax consequences of    
their purchase and ownership of REMIC Regular Certificates.                     

CALL RIGHT                                                                      

The holder of the Call Right will be treated as having purchased a call 
option on all the underlying Mortgage Loans. The price paid by the holder of the
Call Right to purchase such call option will be treated as an option premium and
accordingly will be added to the purchase price of the Mortgage Loans (in       
addition to any exchange fee) if the Mortgage Loans are purchased upon exercise 
of the Call Right, and will be treated as a loss as the Call Right lapses. For a
discussion of when the Call Right may be deemed to lapse, see 'Callable Class   
Certificates' above. Assuming that the underlying Mortgage Loans, if acquired,  
would be a capital asset in such holder's hands, then loss recognized with      
respect to such lapse will be treated as a capital loss.                        

In light of the above, a thrift, REMIC, real estate investment trust or 
regulated investment company should consult its tax advisors before purchasing  
any Call Class.                                                                 

METHODS OF DISTRIBUTION 

Certificates are being offered hereby in Series from time to time (each 
Series evidencing a separate Mortgage Pool) through any of the following        
methods:                                                                        

      1. By negotiated firm commitment underwriting and public reoffering by
underwriters;                                                           

      2. By agency placements through one or more placement agents primarily
with institutional investors and dealers; and                           

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     3. By placement directly by the Company with institutional investors.

    A Prospectus Supplement will be prepared for each Series which will describe
the method of offering being used for that Series and will set forth the        
identity of any underwriters thereof and either the price at which such Series  
is being offered, the nature and amount of any underwriting discounts or        
additional compensation to such underwriters and the proceeds of the offering to
the Company, or the method by which the price at which the underwriters will    
sell the Certificates will be determined. Each Prospectus Supplement for an     
underwritten offering will also contain information regarding the nature of the 
underwriters' obligations, any material relationship between the Company and any
underwriter and, where appropriate, information regarding any discounts or      
concessions to be allowed or reallowed to dealers or others and any arrangements
to stabilize the market for the Certificates so offered. In firm commitment     
underwritten offerings, the underwriters will be obligated to purchase all of   
the Certificates of such Series if any such Certificates are purchased.         
Certificates may be acquired by the underwriters for their own accounts and may 
be resold from time to time in one or more transactions, including negotiated   
transactions, at a fixed public offering price or at varying prices determined  
at the time of sale.                                                            

    WaMu Capital Corp., an affiliate of the Company, or another affiliate of the
Company may from time to time act as agent or underwriter in connection with the
sale of the Certificates.                                                       

  Underwriters and agents may be entitled under agreements entered into with
the Company to indemnification by the Company against certain civil liabilities,
including liabilities under the Securities Act of 1933, as amended (the 'Act'), 
or to contribution with respect to payments which such underwriters or agents   
may be required to make in respect thereof.                                     

If a Series is offered other than through underwriters, the Prospectus  
Supplement relating thereto will contain information regarding the nature of    
such offering and any agreements to be entered into between the Company and     
purchasers of Certificates of such Series.                                      

TRANSFERABILITY OF CERTIFICATES 

The Company anticipates that the Certificates will be sold primarily to 
institutional investors. Purchasers of Certificates, including dealers, may,    
depending on the facts and circumstances of such purchases, be deemed to be     
'underwriters' within the meaning of the Act, in connection with reoffers and   
sales by them of Certificates. Certain purchasers will be required to give the  
Company prior notice of their intention to resell their Certificates, and to    
represent to the Company that they will observe certain Prospectus delivery and 
anti-manipulative requirements of the Act and the Securities Exchange Act of    
1934, as amended. The Company will charge any Certificateholder requesting      
amended or updated Prospectuses or Prospectus Supplements all expenses incurred 
by the Company for preparation and delivery of such documents.                  
Certificateholders should consult with their legal advisors in this regard prior
to any such reoffer or resale.                                                  

LEGAL MATTERS 

Certain legal matters will be passed upon for the Company by David H.   
Zielke, Charles E. Smith or other Company counsel, and by its special counsel,  
Orrick, Herrington & Sutcliffe LLP, San Francisco, California.                  

FINANCIAL INFORMATION 

    The Company has determined that its financial statements are not material to
the offering made hereby. However, any prospective investor who desires to      
review financial information concerning the Company will be provided, upon      
request, with a copy of the consolidated balance sheet of the Company as of     
December 31, 2001 or the end of its last fiscal year, whichever is later, and a 
copy of the most recent statement of earnings of the Company. Such requests     
should be directed to Washington Mutual Mortgage Securities Corp., Controller's 
Department, 75 North Fairway Drive, Vernon Hills, Illinois 60061.               

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INCORPORATION OF DOCUMENTS BY REFERENCE 

    We 'incorporate by reference' into the Prospectus Supplement for each Series
of Certificates the information we file with the Commission with respect to that
Series, which means that we can disclose important information to you by        
referring you to those documents. The information we incorporate by reference   
into a Prospectus Supplement is considered to be part of that Prospectus        
Supplement from the date it was filed, unless we update or supersede that       
information by information we file subsequently that is incorporated by         
reference into that Prospectus Supplement. We incorporate by reference into the 
Prospectus Supplement for each Series of Certificates any documents filed by us 
with the Commission with respect to that Series under Section 13(a), 13(c), 14  
or 15(d) of the Securities Exchange Act of 1934 after the date of that          
Prospectus Supplement and prior to the termination of the offering of that      
Series.                                                                         

Any statement contained in a Prospectus Supplement or in a document     
incorporated or deemed to be incorporated by reference into a Prospectus        
Supplement will be deemed to be modified or superseded for the purposes of that 
Prospectus Supplement to the extent that a statement contained in any other     
subsequently filed document which also is or is deemed to be incorporated by    
reference into that Prospectus Supplement modifies or supersedes the statement. 
Any statement so modified or superseded shall not be deemed, except as so       
modified or superseded, to constitute a part of the Prospectus Supplement.      

We will provide without charge to each person to whom this Prospectus is
delivered in connection with the offering of a Series of Certificates, upon     
written or oral request, copies of any or all of the documents that have been   
incorporated by reference into the related Prospectus Supplement. Requests      
should be directed to Washington Mutual Mortgage Securities Corp., Attn: John   
Race, 75 North Fairway Drive, VHA3B07, Vernon Hills, Illinois 60061, Telephone: 
(847) 549-3113.                                                                 

ADDITIONAL INFORMATION

   This Prospectus, together with the Prospectus Supplement for each Series of
Certificates, contains a summary of the material terms of the applicable        
exhibits to the Registration Statement and the documents referred to herein and 
therein. Copies of such exhibits are on file at the offices of the Securities   
and Exchange Commission in Washington, D.C., may be obtained at rates prescribed
by the Commission upon request to the Commission and may be inspected, without  
charge, at the Commission's offices.                                            

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INDEX OF TERMS

  Set forth below is a list of certain of the more significant terms used in
this Prospectus and the pages on which the definitions of such terms may be     
found.                                                                          

                                                                [Download Table]

                                         PAGE
                                          -- 
                                             
Act....................................   86 
Additional Collateral Loans............   10 
Additional Collateral..................   10 
Advance Claims Endorsement.............   47 
Advances...............................   11 
AFR....................................   78 
Asset Conservation Act.................   61 
Bankruptcy Instrument..................   45 
Bankruptcy Loss........................   45 
Basic Prepayment Assumption............   15 
Budget Act.............................   81 
Buydown Fund...........................    9 
Buydown Fund Account...................   21 
Buydown Loans..........................    9 
Callable Class Certificate.............   75 
CERCLA.................................   61 
Certificate Account....................   28 
Certificate Administrator..............    8 
Certificate Administrator Fee..........   11 
Certificate Interest Rate..............    8 
Closing Date...........................   21 
Code...................................   39 
Commission.............................   10 
Company................................    8 
Compensating Interest..................   14 
Conversion Fee.........................   12 
Cooperative............................    8 
Cooperative Loan.......................    8 
Cooperative Note.......................    8 
Curtailment............................   14 
Custodial Account for P&I..............   25 
Defaulted Mortgage Loss................   45 
Determination Date.....................   31 
Distribution Date......................   20 
Distribution Period....................   29 
DOL....................................   62 
Due Date...............................   14 
Eligible Investments...................   27 
ERISA..................................   62 
Exemption Rating Agencies..............   64 
Extraordinary Losses...................   45 
Fannie Mae Approved Mortgagees.........   16 
FDIC...................................   16 
FHA....................................    9 
FHA Approved Mortgagees................   16 
FHA Insurance Policies.................    9 
Freddie Mac Approved Mortgagees........   16 
Fraud Instrument.......................   45 
Fraud Loss.............................   45 
Garn-St. Germain Act...................   59 
Indemnified Parties....................   37 
Insurance Proceeds.....................   25 
Investment Account.....................   27 
Investment Period......................   26 
IRS....................................   69 
Lenders................................   16 
Letter of Credit.......................   50 
Letter of Credit Bank..................   50 
Liquidation Proceeds...................   25 
Loss...................................   41 
Master Servicer........................    8 
Master Servicing Fee...................   11 
MERS...................................   21 
MERS'r' System.........................   21 
Mortgage Interest Rate.................    9 
Mortgage Loan Servicing Group..........    8 
Mortgage Loans.........................    8 
Mortgage Notes.........................    8 
Mortgage Pool Insurance Policy.........   46 
Mortgaged Properties...................    8 
Mortgages..............................    8 
Net Rate...............................   24 
Non-U.S. Person........................   83 
OID Regulations........................   68 
Parties in Interest....................   62 
Paying Agent...........................   20 
Payoff.................................   14 
Plan Assets............................   62 
Plans..................................   62 
Pooling Agreement......................   11 
Prepayment Assumption..................   70 
Primary Insurance Policy...............   41 
Principal Prepayment...................   15 
PTCE...................................   65 
PTE....................................   63 
RCRA...................................   61 
Record Date............................   20 
Relief Act.............................   60 
REMIC..................................   68 
REMIC Certificates.....................   68 
REMIC Mortgage Pool....................   68 
REMIC Provisions.......................   68 
REMIC Regulations......................   68 
Reserve Account........................   48 
Reserve Fund...........................   50 
Residual Owner.........................   76 

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                                                                [Download Table]

                                         PAGE
                                          -- 
                                             
Retained Yield.........................   24 
Sellers................................    8 
Seller/Servicers.......................    8 
Selling and Servicing Contracts........   19 
Senior Certificates....................   47 
Servicer...............................    9 
Servicing Contracts....................   11 
Servicing Entity.......................    8 
Servicing Fee..........................   11 
Special Hazard Instrument..............   45 
Special Hazard Loss....................   45 
Subordinated Certificates..............   47 
Title V................................   60 
Title VIII.............................   60 
Trust..................................   11 
Trustee................................   11 
UCC....................................   57 
Underwriter's Exemption................   63 
VA.....................................    9 
VA Guaranties..........................    9 
VA Loans...............................    9 
WCC Exemption..........................   63 
Withdrawal Date........................   26 

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WAMU MORTGAGE PASS-THROUGH CERTIFICATES,
SERIES 2005-AR11

WASHINGTON MUTUAL MORTGAGE SECURITIES CORP. 
DEPOSITOR 

WASHINGTON MUTUAL BANK
SERVICER

$3,127,443,100
(APPROXIMATE) 

--------------------- 
PROSPECTUS SUPPLEMENT 
--------------------- 

Underwriters
WAMU CAPITAL CORP.                                         RBS GREENWICH CAPITAL
(Co-Lead Underwriters and Joint Book Running Managers)

YOU SHOULD RELY ONLY ON THE INFORMATION CONTAINED OR INCORPORATED BY    
REFERENCE IN THIS PROSPECTUS SUPPLEMENT AND THE ACCOMPANYING PROSPECTUS. WE HAVE
NOT AUTHORIZED ANYONE TO PROVIDE YOU WITH DIFFERENT INFORMATION.                

    WE ARE NOT OFFERING THE OFFERED CERTIFICATES IN ANY STATE WHERE THE OFFER IS
NOT PERMITTED.                                                                  

WE DO NOT CLAIM THE ACCURACY OF THE INFORMATION IN THIS PROSPECTUS      
SUPPLEMENT AND THE ACCOMPANYING PROSPECTUS AS OF ANY DATE OTHER THAN THE DATES  
STATED ON THEIR RESPECTIVE COVERS.                                              

  DEALERS WILL DELIVER A PROSPECTUS SUPPLEMENT AND PROSPECTUS WHEN ACTING AS
UNDERWRITERS OF THE OFFERED CERTIFICATES AND WITH RESPECT TO THEIR UNSOLD       
ALLOTMENTS OR SUBSCRIPTIONS. IN ADDITION, ALL DEALERS SELLING THE OFFERED       
CERTIFICATES WILL DELIVER A PROSPECTUS SUPPLEMENT AND PROSPECTUS UNTIL          
NOVEMBER 21, 2005.                                                              

STATEMENT OF DIFFERENCES      

The registered trademark symbol shall be expressed as................... 'r'    
The dagger symbol shall be expressed as................................. 'D'    

Dates Referenced Herein   and   Documents Incorporated by Reference

				Referenced-On Page
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		8/25/06		79		80
		11/21/05		184					8-K
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		8/25/05		11		29			424B5,  8-K
Filed on:		8/24/05
		8/23/05		1		95			8-K
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		1/5/00		160
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