花旗美股招股说明书(2026-06-02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 index supplement, prospectus supplement and prospectus are not an offer to 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 JUNE 1, 2026 June, 2026Medium-Term Senior Notes, Series NPricing Supplement No. 2026-USNCH32284Filed Pursuant to Rule 424(b)(2)Registration Statement Nos. 333-293732 and 333-293732-02 Citigroup Global Markets Holdings Market-Linked Securities Linked to the Citi Dynamic Asset Selector 5 Excess Return Index Due January 4, 2028 ▪The securities offered by this pricing supplement are unsecured debt securities issued by Citigroup Global Markets Holdings Inc. and guaranteed by Citigroup Inc. Unlike conventional debtsecurities, the securities do not pay interest. Instead, the securities offer the potential for a positive return at maturity based on the performance of the Index specified below from the initialindex level to the final index level.▪ If the Index appreciates from the initial index level to the final index level, you will receive a positive return at maturity equal to that appreciationmultipliedby the upside participation ratespecified below. However, if the Index remains the same or depreciates, you will be repaid the stated principal amount of your securities at maturity but will not receive any return on yourinvestment. The securities are designed for investors who are willing to forgo interest on the securities and accept the risk of not receiving any return on the securities in exchange for thepossibility of a positive return at maturity based on the performance of the Index. Even if the Index appreciates from the initial index level to the final index level, so that you do receive apositive return at maturity, there is no assurance that your total return at maturity on the securities will compensate you for the effects of inflation or be as great as the yield you could haveachieved on a conventional debt security of ours of comparable maturity.▪ In order to obtain the exposure to the Index that the securities provide, investors must be willing to accept (i) an investment that may have limited or no liquidity and (ii) the risk of notreceiving any amount due under the securities if we and Citigroup Inc. default on our obligations.All payments on the securities are subject to the credit risk of Citigroup GlobalMarkets Holdings Inc. and Citigroup Inc. 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 $916.50 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 receive an underwriting fee of up to $10.00 for each security sold in this offering. The total underwriting fee and proceeds to issuer in the table above give effect to the actual totalunderwriting fee.For more information on the distribution of the securities, see “Supplemental Plan of Distribution” in this pricing supplement. In addition to the underwriting fee, CGMI and its affiliates mayprofit from expected hedging activity related to this offering, even if the value of the securities declines. See “Use of Proceeds and Hedging” in the accompanying prospectus.(3) The per security proceeds to issuer indicated above represent the minimum per security proceeds to issuer for any security, assuming the maximum per security underwriting fee. As noted above, theunderwriting fee is variable. In addition, CGMI will pay to one or more electronic platform providers a fee of up to $2.00 for each security sold in this offering where related selected dealers and/or custodians implement or utilize suchproviders. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities or determined that this pricing supplement and theaccompanying index supplement, prospectus supplement and prospectus are truthful or complete. Any representation to the contrary is a criminal offense.You should read this pricing supplement together with the accompanying index supplement, prospectus supplement and prospectus, which can be accessed via the hyperlinks below:Index Supplement No. IS-02-06 dated February 25, 2026Prospectu