Modeling Assumptions Unless otherwise indicated, the tables that follow are based on the following assumptions (the "Modeling Assumptions"), among others: 1.  The Mortgage Loans underlying the Trust Assets have the characteristics shown under "Characteristics of the Ginnie Mae Multifamily Certificates and the Related Mortgage Loans" in Exhibit A to this Supplement. 2.  There are no voluntary prepayments during any lockout period. 3.  The Mortgage Loans prepay at 100% PLD (as defined under "– Prepayment Assump- tions"  in  this  Supplement)  and,  beginning  on  the  applicable  Lockout  End  Date  (or  if  no lockout  period  applies,  the  applicable  Issue  Date),  at  the  constant  percentages  of  CPR (described below) shown in the related table. 4.  The Issue Date, Lockout End Date and Prepayment Penalty End Date of each Ginnie Mae Multifamily Certificate is the first day of the month indicated on Exhibit A. 5.  Distributions  on  the  Securities,  including  all  distributions  of  prepayments  on  the Mortgage Loans, are always received on the 16th day of the month, whether or not a Business Day, commencing in September 2006. 6.  One hundred percent (100%) of the Prepayment Penalties are received by the Trustee and distributed to Class IO. 7.  A termination of the Trust does not occur. 8.  The Closing Date for the Securities is August 30, 2006. 9.  No expenses or fees are paid by the Trust other than the Trustee Fee. When  reading  the  tables  and  the  related  text,  investors  should  bear  in  mind  that  the Modeling Assumptions, like any other stated assumptions, are unlikely to be entirely consistent with actual experience. •   For example, many Distribution Dates will occur on the first Business Day after the 16th of the month, prepayments may not occur during the Prepayment Penalty Period, and the Trustee may cause a termination of the Trust as described under "Description of the Securities – Termination" in this Supplement. •   In addition, distributions on the Securities are based on Certificate Factors, Corrected Certificate Factors, and Calculated Certificate Factors, if applicable, which may not reflect actual receipts on the Trust Assets. See  "Description  of  the  Securities – Distributions"  in  the  Multifamily  Base  Offering Circular. Prepayment Assumptions Prepayments  of  mortgage  loans  are  commonly  measured  by  a  prepayment  standard  or model. One of the models used in this Supplement is the constant prepayment rate ("CPR") model, which represents an assumed constant rate of voluntary prepayment each month relative to the then outstanding principal balance of the Mortgage Loans to which the model is applied. See "Yield, Maturity and Prepayment Considerations – Prepayment Assumption Models" in the Multifamily Base Offering Circular. In addition, this Supplement uses another model to measure involuntary prepayments. This model is the Project Loan Default or PLD model provided by the Sponsor. The PLD model represents an assumed rate of involuntary prepayments each month as specified in the table below (the "PLD Model Rates"), in each case expressed as a per annum percentage of the then- outstanding principal balance of each of the Mortgage Loans in relation to its loan age. For S-19