8-K 1 csf04ar1.txt MAY 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington D. C. 20549 Form 8-K Current Report Pursuant to Section 13 or 15(d) of The Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 25, 2004 CREDIT SUISSE FIRST BOSTON MORTGAGE SECURITIES CORPORATION Mortgage-Backed Pass-Through Certificates, Series 2004-AR1 Trust (Exact name of registrant as specified in its charter) New York (governing law of 333-107055-18 54-2142321 Pooling and Servicing Agreement) (Commission 54-2142322 (State or other File Number) 54-2142323 jurisdiction 54-2142324 of Incorporation) IRS EIN c/o Wells Fargo Bank, N.A. 9062 Old Annapolis Road Columbia, MD 21045 (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code: (410) 884-2000 (Former name or former address, if changed since last report) ITEM 5. Other Events On May 25, 2004 a distribution was made to holders of CREDIT SUISSE FIRST BOSTON MORTGAGE SECURITIES CORPORATION, Mortgage-Backed Pass-Through Certificates, Series 2004-AR1 Trust. ITEM 7. Financial Statements and Exhibits (c) Exhibits furnished in accordance with Item 601(a) of Regulation S-K Exhibit Number Description EX-99.1 Monthly report distributed to holders of Mortgage-Backed Pass-Through Certificates, Series 2004-AR1 Trust, relating to the May 25, 2004 distribution. Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. CREDIT SUISSE FIRST BOSTON MORTGAGE SECURITIES CORPORATION Mortgage-Backed Pass-Through Certificates, Series 2004-AR1 Trust By: Wells Fargo Bank, N.A. as Trust Administrator By: /s/ Beth Belfield as Assistant Vice President By: Beth Belfield as Assistant Vice President Date: 5/26/04 INDEX TO EXHIBITS Exhibit Number Description EX-99.1 Monthly report distributed to holders of Mortgage-Backed Pass-Through Certificates, Series 2004-AR1 Trust, relating to the May 25, 2004 distribution. EX-99.1

Delinquency Status By Groups

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CSFB MORTGAGE BACKED PASS THR CERTS SER 2004-AR1 8-K