Fitch Rates IndyMac MBS RAST $320.6MM, Series 2005-AR14.

NEW YORK -- Fitch rates IndyMac MBS, Inc., IndyMac INDX Mortgage Loan Trust 2005-AR14, residential mortgage pass-through certificates, as follows:

--$320.6 million class 1-A-A1 'AAA'.

The 'AAA' rating on the senior certificate reflects the subordination provided by the 1-A-1B1 and 1-A-1B2 senior support certificates, as well as the B1 through B8 certificates, which are not rated by Fitch. Fitch believes the above credit enhancement will be adequate to support mortgagor defaults, as well as bankruptcy, fraud, and special hazard losses in limited amounts. In addition, the ratings reflect the quality of the mortgage collateral, the strength of the legal and financial structures, and the capabilities of IndyMac Bank, FSB (IndyMac) as master servicer (rated 'RMS2+' by Fitch).

The mortgage pool consists of two loan groups, each comprised primarily of 30-year conventional, adjustable-rate, negative amortization mortgage loans secured by first liens on one- to four-family residential properties. Loan Group 1 consists of 2,488 loans and had an aggregate loan balance of $576,184,588 as of the cutoff date (June 1, 2005). The average loan balance is $231,585, and the weighted average original loan-to-value ratio (OLTV) for the mortgage loans in Group 1 is approximately 71.78%. The weighted average FICO credit score for the group is approximately 707. Cash-out and rate/term refinance loans represent 66.20% and 13.42% of the group, respectively. Second and investor-occupied homes account for 2.17% and 6.28% of the group, respectively. The states that represent the largest geographic concentration are California (36.40%), Florida (13.98%), and New Jersey (7.39%).

Loan Group 2 consists of 883 loans and had an aggregate loan balance of $426,114,250 as of the cutoff date (June 1, 2005). The average loan balance is $482,575, and the weighted average OLTV for the mortgage loans in Group 2 is approximately 73.76%. The weighted average FICO credit score for the group is approximately 707. Cash-out and rate/term refinance loans represent 56.43% and 9.24% of the group, respectively. Second and investor-occupied homes account for 0.62% and 1.94% of the group, respectively. The states that represent the largest geographic concentration are California (62.08%), Florida (6.57%), and Virginia (6.54%).

None of the mortgage loans are 'high cost' loans as defined under any local, state, or federal laws. For additional information on Fitch's rating criteria regarding predatory lending legislation, see the press release 'Fitch Revises Rating Criteria in Wake of Predatory Lending Legislation,' dated May 1, 2003, available on the Fitch Ratings web site at www.fitchratings.com.

The loans were originated or purchased by IndyMac Bank, F.S.B., which it subsequently sold to IndyMac MBS, Inc. IndyMac MBS, Inc. deposited the loans in the trust, which issued the certificates, representing undivided beneficial ownership in the trust. For federal income tax purposes, elections will be made to treat the trust as separate multiple real estate mortgage investment conduits (REMICs). Deutsche Bank National Trust Company will act as trustee.

Fitch's rating definitions are available on the agency's public web site, www.fitchratings.com. Published ratings, criteria and methodologies, and relevant policies and procedures are also available from this site, at all times. This document will remain on the public site for seven days.