DBRS Rates Credit Suisse First Boston Mortgage Securities Corp., CSMC Series 2009-14R

DBRS has today assigned the following ratings to the Credit Suisse First Boston Mortgage Securities Corp., CSMC Series 2009-14R Notes issued by CSMC Series 2009-14R (the Trust).

-- $72.5 million Class 1-A-1* rated at BBB
-- $38.3 million Class 1-A-3** rated at AAA
-- $6.8 million Class 1-A-4** rated at AAA
-- $6.8 million Class 1-A-5** rated at AA
-- $6.8 million Class 1-A-6** rated at “A”
-- $6.8 million Class 1-A-7** rated at BBB
-- $6.8 million Class 1-A-8** rated at BBB
-- $45.1 million Class 1-A-11* rated at AAA
-- $52.0 million Class 1-A-12* rated at AA
-- $58.8 million Class 1-A-13* rated at “A”
-- $65.6 million Class 1-A-14* rated at BBB

DBRS rates Group 1 in this resecuritization trust, which consists of one seasoned senior residential mortgage-backed security (RMBS). Within Group 1, the AAA, AA, “A” and BBB ratings on the notes reflect the credit enhancement provided by subordination. The ratings also reflect the quality of the underlying security. Certain classes of notes (Exchangeable REMIC Notes) are exchangeable for certain other classes of notes (Exchangeable Notes) and vice versa, in the combinations described in Annex II of the private placement memorandum.

Other than the specified classes above, DBRS does not rate any other securities in this transaction.

Interest and principal payments on the notes will be made generally on the 26th day of each month commencing in November 2009. Interest payments will be distributed on a pro rata basis to the notes, and principal will be distributed on a sequential basis to the notes, in the order of priority specified in the private placement memorandum, until the principal balances thereof are reduced to zero.

Any losses realized from the underlying securities within each group will be allocated in a reverse numerical order to the notes.

The Trust is a resecuritization consisting of six senior RMBS, represented by various real estate mortgage investment conduits (REMICs). The Group 1 underlying certificates consist of the Lehman Mortgage Trust Mortgage Pass-Through Certificates, Series 2007-4 Class 1-A1, which is backed by a pool of Alt-A, fixed-rate, first-lien, one- to four-family residential mortgages.

Notes:

• Denotes Exchangeable Note.
  ** Denotes Exchangeable REMIC Note.

All figures are in U.S. dollars unless otherwise noted.

The applicable methodology is Rating U.S. Residential Mortgage-Backed Securities Transactions, which can be found on our website under Methodologies.

This is a Structured Finance rating.