UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM 10-K

                                  Annual Report
                     Pursuant to Section 13 or 15(d) of the
                        Securities Exchange Act of 1934
                  For the Fiscal Year Ended December 31, 2004

                       Commission file numbers:  333-116432-02

                                 Lehman ABS Corp.

                        State of Incorporation:  Delaware
               I.R.S. Employer Identification Number:  13-3447441

                          745 Seventh Avenue, 7th Floor
                               New York, NY  10019
                                (212) 526 - 7000

                   American Home Mortgage Investment Trust
                               Series 2004-3

              Title of each class of securities covered by this Form:
             IA, IIA, IIIA, IVA, VA, VI-A1, VI-A2, VI-A3, VI-A4, VI-A5,
                        M-H1, M-H2, M-H3, M-F1, M-F2, M-F3

       Securities registered pursuant to Section 12(b) of the Act:  None
       Securities registered pursuant to Section 12(g) of the Act:  None

Indicate whether the Registrant:  (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
Registrant was required to file such reports), and (2) has been subject
to such filing requirements for the past 90 days.    Yes _X_    No ___


                                     PART I

Item 1.  Business:

     Not applicable.

Item 2.  Properties:

     Not applicable.

Item 3.  Legal Proceedings:

     The registrant knows of no material pending legal proceedings involving
     the trust created under the Trust Agreement (the Trust),
     the Trustee, the Master Servicer or the registrant with respect to the
     Trust.

Item 4.  Submission of Matters to a Vote of Security-Holders

     There were no matters submitted to a Vote of the Security Holders.


                                    PART II

Item 5.  Market for Registrant's Common Equity, Related Stockholder Matters
         and Issuer Purchases of Equity Securities.

(a)  There is no established public trading market for the certificates.

(b)  Records provided by the Trustee indicate that there are approximately
     66 holders of record of each class of certificates as of the end of the
     reporting year.

(c)  Not applicable.

Item 6.  Selected Financial Data.

     Not applicable.

Item 7.  Management's Discussion and Analysis of Financial Condition and
         Results of Operation.

     Not applicable.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

     Not applicable.

Item 8.  Financial Statements and Supplementary Data.

     Not applicable.

Item 9.  Changes in and Disagreements with Accountants on Accounting and
         Financial Disclosure.

     Not applicable.

Item 9A. Controls and Procedures.

     Not applicable.

Item 9B. Other Information.

     Not applicable.


                                    PART III

Item 10. Directors and Executive Officers of the Registrant

     Not applicable.

Item 11. Executive Compensation.

     Not applicable.

Item 12. Security Ownership of Certain Beneficial Owners and Management

     Not applicable.

Item 13. Certain Relationships and Related Transactions.

     Not applicable.

Item 14. Principal Accounting Fees and Services.

     Not applicable.


                                    PART IV

Item 15. Exhibits, Financial Statement Schedules.

(a)  Exhibits

    (99.1) Report of Independent Registered Public Accounting Firm,
           American Home Mortgage Servicing Inc. Management Assertion
           and Appendix I

    (99.2) Report of Management as to Compliance with Minimum Servicing
           Standards for the year ended December 31, 2004.

    (99.3) Annual Statement as to Compliance under the Servicing
           Agreements for the year ended December 31, 2004.

    (99.4) Aggregate Statement of Principal and Interest Distributions
           to Certificate Holders



(b)  Not applicable.

(c)  Not applicable.




                                   SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Registrant has duly caused this report to be
signed on its behalf by the undersigned, thereunto duly authorized.


Date:  March 29, 2005
       --------------

     Filed on behalf of Lehman ABS Corp.,
     by American Home Mortgage Servicing, Inc.
     as Master Servicer for American Home Mortgage Investment Trust,
     Mortgage-Backed Notes, Series 2004-3


     By:       /s/   Michael Strauss
               ------------------------------
     Name:     Michael Strauss
     Title:    Chief Executive Officer
     Company:  American Home Mortgage Servicing, Inc.




Certification

I, Michael Strauss, certify that:

1.      I have reviewed this annual report on Form 10-K, and all reports on
Form 8-K containing distribution or servicing reports filed in respect of
periods included in the year covered by this annual report, of American Home
Mortgage Investment Trust 2004-3.

2.      Based on my knowledge, the information in these reports, taken as a
whole, does not contain any untrue statement of a material fact or omit to
state a material fact necessary to make the statements made, in light of the
circumstances under which such statements were made, not misleading as of
the last day of the period covered by this annual report;

3.      Based on my knowledge, the distribution or servicing information
required to be provided to the trustee by the servicer under the pooling
and servicing, or similar, agreement, for inclusion in these reports is
included in these reports;

4.      I am responsible for reviewing the activities performed by the
servicer under the pooling and servicing, or similar, agreement and based
upon my knowledge and the annual compliance review required under that
agreement, and except as disclosed in the reports, the servicer has
fulfilled its obligations under that agreement; and

5.      The reports disclose all significant deficiencies relating to the
servicer's compliance with the minimum servicing standards based upon the
report provided by an independent public accountant, after conducting a
review in compliance with the Uniform Single Attestation Program for
Mortgage Bankers or similar procedure, as set forth in the pooling and
servicing, or similar, agreement, that is included in these reports.

In giving the certifications above, I have reasonably relied on
information provided to me by the following unaffiliated parties:
Citibank, N.A., as Indenture Trustee.

Date: March 29, 2005


By: _/s/ Michael Strauss______________________
Name:   Michael Strauss
Company:  American Home Mortgage Servicing, Inc.
Title:  Chief Executive Officer