Exhibit A Underlying Certificates Trust Asset Group Issuer Series Class Issue Date CUSIP Number Interest Rate Interest Type(1) Final Distribution Date Principal Type(1) Original Principal Balance of Class Underlying Certificate Factor(2) Principal Balance in the Trust Percentage of Class in Trust Approximate Weighted Average Coupon of Mortgage Loans Approximate Weighted Average Remaining Term to Maturity of Mortgage Loans (in months) Approximate Weighted Average Loan Age of Mortgage Loans (in months) Ginnie Mae I or II 2 Ginnie Mae   2003-024 DA   March 28, 2003 38373SF93 5.5% FIX March 2033 SEQ $63,475,000 1.00 $10,475,000 16.5025600630% 6.273% 350 4 II 3 Ginnie Mae   2003-040CE May 30, 2003   38373QYB1 5.5 FIX May 2033 PAC I 21,056,250 1.00 21,056,250 100.0000000000 6.252 355 2 II 4 Ginnie Mae   2002-23 PE April 30, 2002   38373WRT7 6.5 FIX April 2032 PAC 69,430,000 1.00 20,000,000 28.8059916463 7.000 339 17 I 10 Ginnie Mae   2002-38 PG June 28, 2002    38373XCS3 6.5 FIX June 2032 PAC 19,476,000 1.00 19,476,000 100.0000000000 7.000 340 15 I (1)  As defined under "Class Types" in Appendix I to the Base Offering Circular. (2)  Underlying Certificate Factors are as of June 2003. A-1