C: Financial results

Item 2.02 Results of Operations and Financial Condition. ​ On October 13, 2026, Citigroup Inc. announced its results for the quarter ended September 30, 2026. A copy of the related press release, filed as Exhibit 99.1 to this Form 8-K, is incorporated herein by reference. The quotation under the heading “CEO Commentary” on page 1 of Exhibit 99.1 shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 (Act) or otherwise subject to the liabilities under that Section. The information included in Exhibit 99.1, other than in the quotation, shall be deemed “filed” for purposes of the Act. ​ In addition, a copy of the Citigroup Inc. Quarterly Financial Data Supplement for the quarter ended September 30, 2026 is being furnished as Exhibit 99.2 to this Form 8-K and shall not be deemed to be “filed” for purposes of Section 18 of the Act or otherwise subject to the liabilities under that Section. ​ Item 9.01 Financial Statements and Exhibits. ​ (d) Exhibits. ​ Exhibit Number ​ ​ ​ ​ ​ ​ ​ 99.1 ​ Citigroup Inc. press release dated October 13, 2026. ​ ​ ​ 99.2 ​ Citigroup Inc. Quarterly Financial Data Supplement for the quarter ended September 30, 2026. ​ ​ ​ 99.3 ​ Citigroup Inc. securities registered pursuant to Section 12(b) of the Securities Exchange Act of 1934 as of the filing date. ​ ​ ​ 104.1 ​ See the cover page of this Current Report on Form 8-K, formatted in Inline XBRL. ​ ​ ​ ​ 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. ​ ​ ​ CITIGROUP INC. ​ ​ ​ Dated: October 13, 2026 ​ ​ ​ By: /s/ Nicole Giles ​ ​ Nicole Giles ​ ​ Controller and Chief Accounting Officer ​ ​ (Principal Accounting O