花旗集团美股招股说明书(2026-05-01版)

The information in this preliminary pricing supplement is not complete and may be changed. A registration statement relating to these securities has been filed with the Securities andExchange Commission. This preliminary pricing supplement and the accompanying product supplement, underlying supplement, prospectus supplement and prospectus are not an offerto sell these securities, nor are they soliciting an offer to buy these securities, in any state where the offer or sale is not permitted.SUBJECT TO COMPLETION, DATED MAY 1, 2026 May, 2026Medium-Term Senior Notes, Series NPricing Supplement No. 2026-USNCH31803Filed Pursuant to Rule 424(b)(2)Registration Statement Nos. 333-293732 and 333-293732-02 Citigroup Global Markets Holdings ▪The securities offered by this pricing supplement are unsecured debt securities issued by Citigroup Global Markets Holdings Inc. and guaranteed by Citigroup Inc. The securities offer thepotential for periodic contingent coupon payments at an annualized rate that, if all are paid, would produce a yield that is generally higher than the yield on our conventional debt securitiesof the same maturity. In exchange for this higher potential yield, you must be willing to accept the risks that (i) your actual yield may be lower than the yield on our conventional debtsecurities of the same maturity because you may not receive one or more, or any, contingent coupon payments, (ii) the value of what you receive at maturity may be significantly less thanthe stated principal amount of your securities, and may be zero, and (iii) the securities may be automatically called for redemption prior to maturity beginning on the first potential autocalldate specified below. Each of these risks will depend solely on the performance of theworst performingof the underlyings specified below.▪ You will be subject to risks associated with each of the underlyings and will be negatively affected by adverse movements inany one of the underlyings. Although you will have downsideexposure to the worst performing underlying, you will not receive dividends with respect to any underlying or participate in any appreciation of any underlying.▪ All payments due on the securities are fully and unconditionally guaranteed by Citigroup Inc. Valuation dates:June 15, 2026, July 15, 2026, August 17, 2026, September 15, 2026, October 15, 2026, November 16, 2026, December 15, 2026, January 15,2027, February 16, 2027, March 15, 2027, April 15, 2027, May 17, 2027, June 15, 2027, July 15, 2027, August 16, 2027, September 15, 2027,October 15, 2027 and November 15, 2027 (the “final valuation date”), each subject to postponement if such date is not a scheduled trading day orcertain market disruption events occur The third business day after each valuation date, except that the contingent coupon payment date following the final valuation date will be thematurity date of the worst performing underlying on any valuation date is less than its coupon barrier value, you will not receive any contingentcoupon payment on the immediately following contingent coupon payment date. If the securities are not automatically redeemed prior to maturity, you will receive at maturity for each security you then hold (in addition to the finalcontingent coupon payment, if applicable):■If the final underlying value of the worst performing underlying on the final valuation date isgreater than or equal toits initial underlying Payment at maturity: value: $1,000■If the final underlying value of the worst performing underlying on the final valuation date isless thanits initial underlying value and aknock-in eventhas notoccurred: $1,000■If the final underlying value of the worst performing underlying on the final valuation date isless thanits initial underlying value and aknock-in eventhasoccurred:$1,000 + ($1,000 × the underlying return of the worst performing underlying on the final valuation date) If the securities are not automatically redeemed prior to maturity, the final underlying value of the worst performing underlying on thefinal valuation date is less than its initial underlying value and a knock-in event has occurred, you will receive less than the statedprincipal amount of your securities, and possibly nothing, at maturity. Underwriter:Citigroup Global Markets Inc. (“CGMI”), an affiliate of the issuer, acting as principal (1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the securities on the pricing date will be at least $920.00 per security, which will be less than the issue price. Theestimated value of the securities is based on CGMI’s proprietary pricing models and our internal funding rate. It is not an indication of actual profit to CGMI or other of our affiliates, nor is it an indication ofthe price, if any, at which CGMI or any other person may be willing to buy the securities from you at any time after issuance. See “Valuation of the Securities” in this pricing supplement.(2) CGMI will receiv