<Page> U.S. 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) October 26, 2001 --------------------------- Citigroup Inc. -------------------------------------------------------------------------------- (Exact name of registrant as specified in its charter) Delaware 1-9924 52-1568099 --------------- ----------- ------------------- (State or other (Commission (IRS Employer jurisdiction of File Number) Identification No.) incorporation) 399 Park Avenue, New York, New York 10043 -------------------------------------------------------------------------------- (Address of principal executive offices) (Zip Code) (212) 559-1000 -------------------------------------------------------------------------------- (Registrant's telephone number, including area code) <Page> Citigroup Inc. Current Report on Form 8-K Item 5. Other Events. Attached hereto as Exhibit 99.01 and incorporated by reference herein is the Historical Annual Supplement of Citigroup Inc. and subsidiaries ("Citigroup"). Following the November 30, 2000 acquisition of Associates First Capital Corporation ("Associates"), which was accounted for as a pooling of interests, Citigroup presented the results of Associates as a separate operating segment. In connection with the 2001 integration of Associates' businesses into existing Citigroup businesses, Citigroup changed its operating segments presentation to include the various Associates businesses within the other existing operating segments of Citigroup. As a result, all relevant disclosures contained in the Historical Annual Supplement of Citigroup have been restated to reflect this new segment presentation for all periods presented. Item 7. Financial Statements, Pro Forma Financial Information and Exhibits. (a) Not applicable. (b) Not applicable. (c) Exhibits Exhibit Number Description of Exhibit -------------- ---------------------- 99.01 Historical Annual Supplement <Page> SIGNATURE 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. Dated: October 26, 2001 CITIGROUP INC. By: /s/ Roger W. Trupin --------------------------- Name: Roger W. Trupin Title: Controller