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 and Exchange Commission. This preliminary pricing supplement and the accompanying product 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 APRIL 8, 2024

Citigroup Global Markets Holdings Inc.

April , 2024 Medium-Term Senior Notes, Series N Pricing Supplement No. 2024-USNCH[ ] Filed Pursuant to Rule 424(b)(2) Registration Statement Nos. 333-270327 and 333-270327-01

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

Overview

▪ 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 debt securities, the securities do not pay interest and do not repay a fixed amount of principal at maturity. Instead, the securities offer a payment at maturity that may be greater than, equal to or less than the stated principal amount, depending on the performance of shares of the Invesco S&P 500^® Equal Weight ETF (the “underlying shares”) from the initial share price to the final share price.

▪ The securities offer modified exposure to the performance of the underlying shares, with a fixed return at maturity if the price of the underlying shares remains the same or appreciates from the initial share price to the final share price, regardless of the extent of that appreciation. The securities also offer contingent downside protection against loss for a limited range of potential depreciation of the underlying shares. In exchange for those features, investors in the securities must be willing to forgo participation in any appreciation of the underlying shares in excess of the fixed return and any dividends that may be paid on the underlying shares. In addition, investors in the securities must be willing to accept full downside exposure to the underlying shares if the underlying shares depreciate by more than 10.00%. If the underlying shares depreciate by more than 10.00% from the pricing date to the valuation date, you will lose 1% of the stated principal amount of your securities for every 1% by which the final share price is less than the initial share price. There is no minimum payment at maturity.

▪ In order to obtain the modified exposure to the underlying shares 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 not receiving 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 Global Markets Holdings Inc. and Citigroup Inc.

KEY TERMS
Issuer:	Citigroup Global Markets Holdings Inc., a wholly owned subsidiary of Citigroup Inc.
Guarantee:	All payments due on the securities are fully and unconditionally guaranteed by Citigroup Inc.
Underlying shares:	Shares of the Invesco S&P 500® Equal Weight ETF (ticker symbol: “RSP”) (the “underlying share issuer” or the “ETF”)
Aggregate stated principal amount:	$
Stated principal amount:	$1,000 per security
Pricing date:	April     , 2024 (expected to be April 30, 2024)
Issue date:	May     , 2024 (expected to be May 3, 2024)
Valuation date:	April     , 2026 (expected to be April 30, 2026), subject to postponement if such date is not a scheduled trading day or if certain market disruption events occur
Maturity date:	May       , 2026 (expected to be May 5, 2026)
Payment at maturity:	For each $1,000 stated principal amount security you hold at maturity: ▪If the final share price is greater than or equal to the initial share price: $1,000 + the fixed return amount ▪If the final share price is less than the initial share price but greater than or equal to the trigger price: $1,000 ▪If the final share price is less than the trigger price: $1,000 + ($1,000 × the share return) If the final share price is less than the trigger price, your payment at maturity will be less, and possibly significantly less, than $900.00 per security. You should not invest in the securities unless you are willing and able to bear the risk of losing a significant portion and up to all of your investment.
Initial share price:	$     , the closing price of the underlying shares on the pricing date
Final share price:	The closing price of the underlying shares on the valuation date
Fixed return amount:	The fixed return amount will be $203.00 per security (20.30% of the stated principal amount). You will receive the fixed return amount only if the final share price is greater than or equal to the initial share price.
Share return:	(i) The final share price minus the initial share price, divided by (ii) the initial share price
Trigger price:	$     , 90.00% of the initial share price
Listing:	The securities will not be listed on any securities exchange
CUSIP / ISIN:	17331A2T7 / US17331A2T71
Underwriter:	Citigroup Global Markets Inc. (“CGMI”), an affiliate of the issuer, acting as principal
Underwriting fee and issue price:	Issue price(1)(2)	Underwriting fee	Proceeds to issuer
Per security:	$1,000.00	$20.00(2)	$975.00
		$5.00(3)
Total:	$	$	$

(1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the securities on the pricing date will be at least $910.50 per security, which will be less than the issue price. The estimated 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 of the 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, an affiliate of Citigroup Global Markets Holdings Inc. and the underwriter of the sale of the securities, is acting as principal and will receive an underwriting fee of $25.00 for each $1,000.00 security sold in this offering. Certain selected dealers, including Morgan Stanley Wealth Management, and their financial advisors will collectively receive from CGMI a fixed selling concession of $20.00 for each $1,000.00 security they sell. Additionally, it is possible that CGMI and its affiliates may profit 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) Reflects a structuring fee payable to Morgan Stanley Wealth Management by CGMI of $5.00 for each security.

Investing in the securities involves risks not associated with an investment in conventional debt securities. See “Summary Risk Factors” beginning on page PS-6.

Neither the Securities and Exchange Commission (the “SEC”) nor any state securities commission has approved or disapproved of the securities or determined that this pricing supplement and the accompanying product 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 product supplement, prospectus supplement and prospectus, which can be accessed via the hyperlinks below:

Product Supplement No. EA-02-10 dated March 7, 2023                       Prospectus Supplement and Prospectus each dated March 7, 2023

The securities are not bank deposits and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency, nor are they obligations of, or guaranteed by, a bank.

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

Additional Information

General. The terms of the securities are set forth in the accompanying product supplement, prospectus supplement and prospectus, as supplemented by this pricing supplement. The accompanying product supplement, prospectus supplement and prospectus contain important disclosures that are not repeated in this pricing supplement. For example, certain events may occur that could affect your payment at maturity, such as market disruption events and other events affecting the underlying shares. These events and their consequences are described in the accompanying product supplement in the sections “Description of the Securities—Consequences of a Market Disruption Event; Postponement of a Valuation Date,” “Description of the Securities—Certain Additional Terms for Securities Linked to an Underlying Company or an Underlying ETF—Dilution and Reorganization Adjustments” and “Description of the Securities—Certain Additional Terms for Securities Linked to an Underlying Company or an Underlying ETF—Delisting, Liquidation or Termination of an Underlying ETF,” and not in this pricing supplement. It is important that you read the accompanying product supplement, prospectus supplement and prospectus together with this pricing supplement in deciding whether to invest in the securities. Certain terms used but not defined in this pricing supplement are defined in the accompanying product supplement.

Dilution and Reorganization Adjustments. The initial share price and the trigger price are each a “Relevant Value” for purposes of the section “Description of the Securities—Certain Additional Terms for Securities Linked to an Underlying Company or an Underlying ETF—Dilution and Reorganization Adjustments” in the accompanying product supplement. Accordingly, the initial share price and the trigger price are each subject to adjustment upon the occurrence of any of the events described in that section.

April 2024 PS-2

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

Investment Summary

The securities can be used:

▪ As an alternative to direct exposure to the underlying shares that provides a fixed return of 20.30% if the underlying shares have not depreciated as of the valuation date;

▪ To enhance returns and potentially outperform the underlying shares in a moderately bullish scenario, without taking into account lost dividend yield; and

▪ To obtain contingent protection against the loss of principal in the event of a decline of the underlying shares as of the valuation date, but only if the final share price is greater than or equal to the trigger price.

If the final share price is less than the trigger price, the securities are exposed on a 1-to-1 basis to the percentage decline of the final share price from the initial share price. Accordingly, investors may lose their entire initial investment in the securities.

Maturity:	Approximately 2 years
Fixed return amount:	$203.00 per security (20.30% of the stated principal amount)
Trigger price:	90.00% of the initial share price
Minimum payment at maturity:	None.  Investors may lose their entire initial investment in the securities.
Interest:	None

Key Investment Rationale

This approximately 2-year investment does not pay interest but offers a fixed return of 20.30% at maturity if the price of the underlying shares remains the same or appreciates from the initial share price to the final share price and contingent protection against depreciation in the underlying shares of up to 10.00% from the initial share price to the final share price. However, if the underlying shares depreciate by more than 10.00% from the initial share price to the final share price, the payment at maturity will be less than $900.00 per security, and could be zero. Investors may lose their entire initial investment in the securities. All payments on the securities are subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc.

Upside Scenario:	If the final share price is greater than or equal to the initial share price, the payment at maturity for each security will be equal to $1,000 plus the fixed return amount.
Par Scenario:	If the final share price is less than the initial share price but greater than or equal to the trigger price, which means that the underlying shares have depreciated by no more than 10.00% from the initial share price to the final share price, the payment at maturity will be $1,000 per security.
Downside Scenario:	If the final share price is less than the trigger price, which means that the underlying shares have depreciated by more than 10.00% from the initial share price to the final share price, you will lose 1% for every 1% decline in the value of the underlying shares from the initial share price to the final share price (e.g., a 50% depreciation in the underlying shares will result in a payment at maturity of $500.00 per security). There is no minimum payment at maturity on the securities, and investors may lose their entire initial investment.

April 2024 PS-3

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

Hypothetical Examples

The diagram below illustrates your payment at maturity for a range of hypothetical share returns.

Investors in the securities will not receive any dividends that may be paid on the underlying shares or the securities held by the ETF. The diagram and examples below do not show any effect of lost dividend yield over the term of the securities. See “Summary Risk Factors—Investing in the securities is not equivalent to investing in the underlying shares” below.

Trigger Jump SecuritiesPayment at Maturity Diagram
n The Securities	n The Underlying Shares

The examples below are based on a hypothetical initial share price of $100.00 and a hypothetical trigger price of $90.00, and do not reflect the actual initial share price or trigger price. For the actual initial share price and trigger price, see the cover page of this pricing supplement. We have used these hypothetical values, rather than the actual values, to simplify the calculations and aid understanding of how the securities work. However, you should understand that the actual payment at maturity on the securities will be calculated based on the actual initial share price and trigger price and not the hypothetical values indicated below. For ease of analysis, figures below may have been rounded.

Example 1—Upside Scenario A. The hypothetical final share price is $105.00 (a 5.00% increase from the hypothetical initial share price), which is greater than the hypothetical initial share price by less than the fixed return of 20.30%.

Payment at maturity per security = $1,000 + fixed return amount

= $1,000 + $203.00

= $1,203.00

Because the underlying shares appreciated from the hypothetical initial share price to the hypothetical final share price, your total return on the securities at maturity in this scenario would equal the fixed return of 20.30%.

April 2024 PS-4

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

Example 2—Upside Scenario B. The hypothetical final share price is $175.00 (a 75.00% increase from the hypothetical initial share price), which is greater than the hypothetical initial share price by more than the fixed return of 20.30%.

Payment at maturity per security = $1,000 + fixed return amount

= $1,000 + $203.00

= $1,203.00

Because the underlying shares appreciated from the hypothetical initial share price to the hypothetical final share price, your total return on the securities at maturity in this scenario would equal the fixed return of 20.30%. In this scenario, an investment in the securities would underperform a hypothetical alternative investment providing 1-to-1 exposure to the appreciation of the underlying shares without a fixed return.

Example 3—Par Scenario. The hypothetical final share price is $95.00 (a 5.00% decrease from the hypothetical initial share price), which is less than the hypothetical initial share price but greater than the hypothetical trigger price.

Payment at maturity per security = $1,000.00

Because the underlying shares did not depreciate from the hypothetical initial share price to the hypothetical final share price by more than 10.00%, your payment at maturity in this scenario would be equal to the $1,000 stated principal amount per security.

Example 4—Downside Scenario. The hypothetical final share price is $30.00 (a 70.00% decrease from the hypothetical initial share price), which is less than the hypothetical trigger price.

Payment at maturity per security = $1,000 + ($1,000 × the share return)

= $1,000 + ($1,000 × -70.00%)

= $1,000 + -$700.00

= $300.00

Because the underlying shares depreciated from the hypothetical initial share price to the hypothetical final share price by more than 10.00%, your payment at maturity in this scenario would reflect 1-to-1 exposure to the negative performance of the underlying shares.

April 2024 PS-5

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

Summary Risk Factors

An investment in the securities is significantly riskier than an investment in conventional debt securities. The securities are subject to all of the risks associated with an investment in our conventional debt securities that are guaranteed by Citigroup Inc., including the risk that we and Citigroup Inc. may default on our obligations under the securities, and are also subject to risks associated with the underlying shares. Accordingly, the securities are appropriate only for investors who are capable of understanding the complexities and risks of the securities. You should consult your own financial, tax and legal advisors as to the risks of an investment in the securities and the appropriateness of the securities in light of your particular circumstances.

The following is a summary of certain key risk factors for investors in the securities. You should read this summary together with the more detailed description of risks relating to an investment in the securities contained in the section “Risk Factors Relating to the Securities” beginning on page EA-7 in the accompanying product supplement. You should also carefully read the risk factors included in the accompanying prospectus supplement and in the documents incorporated by reference in the accompanying prospectus, including Citigroup Inc.’s most recent Annual Report on Form 10-K and any subsequent Quarterly Reports on Form 10-Q, which describe risks relating to the business of Citigroup Inc. more generally.

Citigroup Inc. will release quarterly earnings on April 12, 2024, which is during the marketing period and prior to the pricing date of these securities.

▪ You may lose a significant portion or all of your investment. Unlike conventional debt securities, the securities do not repay a fixed amount of principal at maturity. Instead, your payment at maturity will depend on the performance of the underlying shares. If the final share price is less than the trigger price, you will lose 1% of the stated principal amount of the securities for every 1% by which the final share price is less than the initial share price. There is no minimum payment at maturity on the securities, and you could lose your entire investment.

▪ The trigger feature of the securities exposes you to particular risks. If the final share price is less than the trigger price, the contingent downside protection against loss for a limited range of potential depreciation of the underlying shares offered by the securities will not apply and you will lose 1% of the stated principal amount of the securities for every 1% by which the final share price is less than the initial share price. Unlike securities with a non-contingent downside protection feature, the securities offer no protection at all if the underlying shares depreciate by more than 10.00% from the initial share price to the final share price. As a result, you may lose your entire investment in the securities.

▪ The securities do not pay interest. Unlike conventional debt securities, the securities do not pay interest or any other amounts prior to maturity. You should not invest in the securities if you seek current income during the term of the securities.

▪ Your potential return on the securities is limited. If the underlying shares appreciate, your potential total return on the securities at maturity is limited to the fixed return at maturity of 20.30%, which is equivalent to a fixed return amount of $203.00 per security. Your return on the securities will not exceed the fixed return, even if the underlying shares appreciate by significantly more than the fixed return. If the underlying shares appreciate by more than the fixed return, the securities will underperform an alternative investment providing 1-to-1 exposure to the performance of the underlying shares. When lost dividends are taken into account, the securities may underperform an alternative investment providing 1-to-1 exposure to the performance of the underlying shares even if the underlying shares appreciate by less than the fixed return.

▪ Investing in the securities is not equivalent to investing in the underlying shares. You will not have voting rights, rights to receive any dividends or other distributions or any other rights with respect to the underlying shares. The payment scenarios described in this pricing supplement do not show any effect of lost dividend yield over the term of the securities.

▪ Your payment at maturity depends on the closing price of the underlying shares on a single day. Because your payment at maturity depends on the closing price of the underlying shares solely on the valuation date, you are subject to the risk that the closing price of the underlying shares on that day may be lower, and possibly significantly lower, than on one or more other dates during the term of the securities. If you had invested directly in the underlying shares or in another instrument linked to the underlying shares that you could sell for full value at a time selected by you, or if the payment at maturity were based on an average of closing prices of the underlying shares, you might have achieved better returns.

▪ The securities are subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc. If we default on our obligations under the securities and Citigroup Inc. defaults on its guarantee obligations, you may not receive any amount owed to you under the securities.

▪ The securities will not be listed on any securities exchange and you may not be able to sell them prior to maturity. The securities will not be listed on any securities exchange. Therefore, there may be little or no secondary market for the securities. CGMI currently intends to make a secondary market in relation to the securities and to provide an indicative bid price for the securities on a daily basis. Any indicative bid price for the securities provided by CGMI will be determined in CGMI’s sole

April 2024 PS-6

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

discretion, taking into account prevailing market conditions and other relevant factors, and will not be a representation by CGMI that the securities can be sold at that price, or at all. CGMI may suspend or terminate making a market and providing indicative bid prices without notice, at any time and for any reason. If CGMI suspends or terminates making a market, there may be no secondary market at all for the securities because it is likely that CGMI will be the only broker-dealer that is willing to buy your securities prior to maturity. Accordingly, an investor must be prepared to hold the securities until maturity.

▪ The estimated value of the securities on the pricing date, based on CGMI’s proprietary pricing models and our internal funding rate, will be less than the issue price. The difference is attributable to certain costs associated with selling, structuring and hedging the securities that are included in the issue price. These costs include (i) the selling concessions and structuring fees paid in connection with the offering of the securities, (ii) hedging and other costs incurred by us and our affiliates in connection with the offering of the securities and (iii) the expected profit (which may be more or less than actual profit) to CGMI or other of our affiliates in connection with hedging our obligations under the securities. These costs adversely affect the economic terms of the securities because, if they were lower, the economic terms of the securities would be more favorable to you. The economic terms of the securities are also likely to be adversely affected by the use of our internal funding rate, rather than our secondary market rate, to price the securities. See “The estimated value of the securities would be lower if it were calculated based on our secondary market rate” below.

▪ The estimated value of the securities was determined for us by our affiliate using proprietary pricing models. CGMI derived the estimated value disclosed on the cover page of this pricing supplement from its proprietary pricing models. In doing so, it may have made discretionary judgments about the inputs to its models, such as the volatility of the underlying shares, the dividend yields on the underlying shares and the securities held by the ETF and interest rates. CGMI’s views on these inputs may differ from your or others’ views, and as an underwriter in this offering, CGMI’s interests may conflict with yours. Both the models and the inputs to the models may prove to be wrong and therefore not an accurate reflection of the value of the securities. Moreover, the estimated value of the securities set forth on the cover page of this pricing supplement may differ from the value that we or our affiliates may determine for the securities for other purposes, including for accounting purposes. You should not invest in the securities because of the estimated value of the securities. Instead, you should be willing to hold the securities to maturity irrespective of the initial estimated value.

▪ The estimated value of the securities would be lower if it were calculated based on our secondary market rate. The estimated value of the securities included in this pricing supplement is calculated based on our internal funding rate, which is the rate at which we are willing to borrow funds through the issuance of the securities. Our internal funding rate is generally lower than our secondary market rate, which is the rate that CGMI will use in determining the value of the securities for purposes of any purchases of the securities from you in the secondary market. If the estimated value included in this pricing supplement were based on our secondary market rate, rather than our internal funding rate, it would likely be lower. We determine our internal funding rate based on factors such as the costs associated with the securities, which are generally higher than the costs associated with conventional debt securities, and our liquidity needs and preferences. Our internal funding rate is not an interest rate that we will pay to investors in the securities, which do not bear interest.

Because there is not an active market for traded instruments referencing our outstanding debt obligations, CGMI determines our secondary market rate based on the market price of traded instruments referencing the debt obligations of Citigroup Inc., our parent company and the guarantor of all payments due on the securities, but subject to adjustments that CGMI makes in its sole discretion. As a result, our secondary market rate is not a market-determined measure of our creditworthiness, but rather reflects the market’s perception of our parent company’s creditworthiness as adjusted for discretionary factors such as CGMI’s preferences with respect to purchasing the securities prior to maturity.

▪ The estimated value of the securities is not an indication of the price, if any, at which CGMI or any other person may be willing to buy the securities from you in the secondary market. Any such secondary market price will fluctuate over the term of the securities based on the market and other factors described in the next risk factor. Moreover, unlike the estimated value included in this pricing supplement, any value of the securities determined for purposes of a secondary market transaction will be based on our secondary market rate, which will likely result in a lower value for the securities than if our internal funding rate were used. In addition, any secondary market price for the securities will be reduced by a bid-ask spread, which may vary depending on the aggregate stated principal amount of the securities to be purchased in the secondary market transaction, and the expected cost of unwinding related hedging transactions. As a result, it is likely that any secondary market price for the securities will be less than the issue price.

▪ The value of the securities prior to maturity will fluctuate based on many unpredictable factors. The value of your securities prior to maturity will fluctuate based on the price and volatility of the underlying shares and a number of other factors, including the price and volatility of the securities held by the ETF, the dividend yields on the underlying shares and the securities held by the ETF, interest rates generally, the time remaining to maturity and our and/or Citigroup Inc.’s creditworthiness, as reflected in our secondary market rate. Changes in the price of the underlying shares may not result in a comparable change in the value of your

April 2024 PS-7

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

securities. You should understand that the value of your securities at any time prior to maturity may be significantly less than the issue price.

▪ Immediately following issuance, any secondary market bid price provided by CGMI, and the value that will be indicated on any brokerage account statements prepared by CGMI or its affiliates, will reflect a temporary upward adjustment. The amount of this temporary upward adjustment will steadily decline to zero over the temporary adjustment period. See “Valuation of the Securities” in this pricing supplement.

▪ Governmental regulatory actions, such as sanctions, could adversely affect your investment in the securities. Governmental regulatory actions, including, without limitation, sanctions-related actions by the U.S. or a foreign government, could prohibit or otherwise restrict persons from holding the securities or underlying shares, or engaging in transactions in them, and any such action could adversely affect the value of underlying shares. These regulatory actions could result in restrictions on the securities and could result in the loss of a significant portion or all of your initial investment in the securities, including if you are forced to divest the securities due to the government mandates, especially if such divestment must be made at a time when the value of the securities has declined.

▪ Our offering of the securities does not constitute a recommendation of the underlying shares. The fact that we are offering the securities does not mean that we believe that investing in an instrument linked to the underlying shares is likely to achieve favorable returns. In fact, as we are part of a global financial institution, our affiliates may have positions (including short positions) in the underlying shares or the securities held by the ETF or in instruments related to the underlying shares or such securities and may publish research or express opinions, that in each case are inconsistent with an investment linked to the underlying shares. These and other activities of our affiliates may affect the price of the underlying shares in a way that has a negative impact on your interests as a holder of the securities.

▪ The price of the underlying shares may be adversely affected by our or our affiliates’ hedging and other trading activities. We expect to hedge our obligations under the securities through CGMI or other of our affiliates, who may take positions directly in the underlying shares or the securities held by the ETF and other financial instruments related to the underlying shares or such securities and may adjust such positions during the term of the securities. Our affiliates also trade the underlying shares or the securities held by the ETF and other financial instruments related to the underlying shares or such securities on a regular basis (taking long or short positions or both), for their accounts, for other accounts under their management or to facilitate transactions on behalf of customers. These activities could affect the price of the underlying shares in a way that negatively affects the value of the securities. They could also result in substantial returns for us or our affiliates while the value of the securities declines.

▪ We and our affiliates may have economic interests that are adverse to yours as a result of our affiliates’ business activities. Our affiliates may currently or from time to time engage in business with the underlying share issuer or the issuers of the securities held by the ETF, including extending loans to, making equity investments in or providing advisory services to such issuers. In the course of this business, we or our affiliates may acquire non-public information about such issuers, which we will not disclose to you. Moreover, if any of our affiliates is or becomes a creditor of any such issuer, they may exercise any remedies against any such issuer that are available to them without regard to your interests.

▪ The price and performance of the underlying shares may not completely track the performance of its underlying index or the net asset value per share of the underlying share issuer. The underlying share issuer does not fully replicate the underlying index that it seeks to track (the “ETF underlying index”) and may hold securities different from those included in the ETF underlying index. In addition, the performance of the underlying shares reflects additional transaction costs and fees that are not included in the calculation of the ETF underlying index. All of these factors may lead to a lack of correlation between the performance of the underlying shares and the ETF underlying index. In addition, corporate actions with respect to the equity securities constituting the ETF underlying index or held by the underlying share issuer (such as mergers and spin-offs) may impact the variance between the performance of the underlying shares and the ETF underlying index. Finally, because the underlying shares are traded on NYSE Arca, Inc. and are subject to market supply and investor demand, the market value of the underlying shares may differ from the net asset value per share of the underlying share issuer.

During periods of market volatility, securities underlying the underlying shares may be unavailable in the secondary market, market participants may be unable to calculate accurately the net asset value per share of the underlying share issuer and the liquidity of the underlying shares may be adversely affected. This kind of market volatility may also disrupt the ability of market participants to create and redeem underlying shares. Further, market volatility may adversely affect, sometimes materially, the price at which market participants are willing to buy and sell the underlying shares. As a result, under these circumstances, the market value of the underlying shares may vary substantially from the net asset value per share of the underlying share issuer. For all of the foregoing reasons, the performance of the underlying shares might not correlate with the performance of the ETF underlying index and/or the net asset value per share of the underlying share issuer, which could materially and adversely affect the value of the securities in the secondary market and/or reduce your return on the securities.

April 2024 PS-8

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

▪ Even if the underlying share issuer pays a dividend that it identifies as special or extraordinary, no adjustment will be required under the securities for that dividend unless it meets the criteria specified in the accompanying product supplement. In general, an adjustment will not be made under the terms of the securities for any cash dividend paid on the underlying shares unless the amount of the dividend per underlying share, together with any other dividends paid in the same fiscal quarter, exceeds the dividend paid per underlying share in the most recent fiscal quarter by an amount equal to at least 10% of the closing price of the underlying shares on the date of declaration of the dividend. Any dividend will reduce the closing price of the underlying shares by the amount of the dividend per underlying share. If the underlying share issuer pays any dividend for which an adjustment is not made under the terms of the securities, holders of the securities may be adversely affected. See “Description of the Securities— Certain Additional Terms for Securities Linked to an Underlying Company or an Underlying ETF—Dilution and Reorganization Adjustments—Certain Extraordinary Cash Dividends” in the accompanying product supplement.

▪ The securities will not be adjusted for all events that could affect the price of the underlying shares. For example, we will not make any adjustment for ordinary dividends or extraordinary dividends that do not meet the criteria described above. Moreover, the adjustments we do make may not fully offset the dilutive or adverse effect of the particular event. Investors in the securities may be adversely affected by such an event in a circumstance in which a direct holder of the underlying shares would not.

▪ The securities may become linked to shares of an issuer other than the original underlying share issuer upon the occurrence of a reorganization event or upon the delisting of the underlying shares. For example, if the underlying share issuer enters into a merger agreement that provides for holders of the underlying shares to receive shares of another entity, the shares of such other entity will become the underlying shares for all purposes of the securities upon consummation of the merger. Additionally, if the underlying shares are delisted or the underlying share issuer is otherwise terminated, the calculation agent may, in its sole discretion, select shares of another issuer to be the underlying shares. See “Description of the Securities— Certain Additional Terms for Securities Linked to an Underlying Company or an Underlying ETF—Dilution and Reorganization Adjustments” and “—Delisting, Liquidation or Termination of an Underlying ETF” in the accompanying product supplement.

▪ The calculation agent, which is an affiliate of ours, will make important determinations with respect to the securities. If certain events occur during the term of the securities, such as market disruption events and other events with respect to the underlying share issuer that may require a dilution adjustment or the delisting of the underlying shares, CGMI, as calculation agent, will be required to make discretionary judgments that could significantly affect your return on the securities. In making these judgments, the calculation agent’s interests as an affiliate of ours could be adverse to your interests as a holder of the securities.

▪ Changes made by the investment adviser to the underlying share issuer or by the sponsor of the index underlying the underlying shares may adversely affect the underlying shares. We are not affiliated with the investment adviser to the underlying share issuer or with the sponsor of the index underlying the underlying shares. Accordingly, we have no control over any changes such investment adviser or sponsor may make to the underlying share issuer or the index underlying the underlying shares. Such changes could be made at any time and could adversely affect the performance of the underlying shares.

▪ The U.S. federal tax consequences of an investment in the securities are unclear. There is no direct legal authority regarding the proper U.S. federal tax treatment of the securities, and we do not plan to request a ruling from the Internal Revenue Service (the “IRS”). Consequently, significant aspects of the tax treatment of the securities are uncertain, and the IRS or a court might not agree with the treatment of the securities as prepaid forward contracts. If the IRS were successful in asserting an alternative treatment of the securities, the tax consequences of the ownership and disposition of the securities might be materially and adversely affected. Even if the treatment of the securities as prepaid forward contracts is respected, a security may be treated as a “constructive ownership transaction,” with potentially adverse consequences described below under “United States Federal Tax Considerations.” Moreover, future legislation, Treasury regulations or IRS guidance could adversely affect the U.S. federal tax treatment of the securities, possibly retroactively.

If you are a non-U.S. investor, you should review the discussion of withholding tax issues in “United States Federal Tax Considerations—Non-U.S. Holders” below.

You should read carefully the discussion under “United States Federal Tax Considerations” and “Risk Factors Relating to the Securities” in the accompanying product supplement and “United States Federal Tax Considerations” in this pricing supplement. You should also consult your tax adviser regarding the U.S. federal tax consequences of an investment in the securities, as well as tax consequences arising under the laws of any state, local or non-U.S. taxing jurisdiction.

April 2024 PS-9

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

Information About the Invesco S&P 500^® Equal Weight ETF

The Invesco S&P 500^® Equal Weight ETF is an exchange-traded fund that seeks to provide investment results that, before expenses, correspond generally to the performance of the S&P 500^® Equal Weight Index. The S&P 500^® Equal Weight Index is the equal-weight version of the S&P 500^® Index. The Invesco S&P 500^® Equal Weight ETF is managed by Invesco Exchange-Traded Fund Trust. Invesco Capital Management LLC is the investment adviser to the Invesco S&P 500^® Equal Weight ETF.

Information provided to or filed with the SEC by the Invesco S&P 500^® Equal Weight ETF pursuant to the Securities Act of 1933, as amended, and the Investment Company Act of 1940, as amended, can be located by reference to SEC file numbers 333-102228 and 811-21265, respectively, through the SEC’s website at http://www.sec.gov. In addition, information may be obtained from other sources including, but not limited to, press releases, newspaper articles and other publicly disseminated documents. The underlying shares of the Invesco S&P 500^® Equal Weight ETF trade on the NYSE Arca under the ticker symbol “RSP.”

This pricing supplement relates only to the securities offered hereby and does not relate to the underlying shares or other securities of the underlying share issuer. We have derived all disclosures contained in this pricing supplement regarding the underlying shares and the underlying share issuer from the publicly available documents described above. In connection with the offering of the securities, none of Citigroup Global Markets Holdings Inc., Citigroup Inc. or CGMI has participated in the preparation of such documents or made any due diligence inquiry with respect to the underlying share issuer or the underlying shares.

The securities represent obligations of Citigroup Global Markets Holdings Inc. (guaranteed by Citigroup Inc.) only. The underlying share issuer is not involved in any way in this offering and has no obligation relating to the securities or to holders of the securities.

Neither we nor any of our affiliates make any representation to you as to the performance of the underlying shares.

Historical Information

The graph below shows the closing prices of the underlying shares for each day such price was available from January 2, 2014 to April 4, 2024. The table that follows shows the high and low closing prices of, and dividends paid on, the underlying shares for each quarter in that same period. We obtained the closing prices and other information below from Bloomberg L.P., without independent verification. You should not take the historical prices of the underlying shares as an indication of future performance.

Shares of the Invesco S&P 500^® Equal Weight ETF – Historical Closing Prices*
January 2, 2014 to April 4, 2024

* The red line indicates the hypothetical trigger price of $148.860, assuming the closing price on April 4, 2024 were the initial share price.

April 2024 PS-10

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

Shares of the Invesco S&P 500® Equal Weight ETF	High	Low	Dividends
2014
First Quarter	$73.55	$67.44	$0.28158
Second Quarter	$76.78	$70.76	$0.27970
Third Quarter	$78.32	$74.20	$0.26805
Fourth Quarter	$81.27	$71.68	$0.33515
2015
First Quarter	$82.65	$77.13	$0.32637
Second Quarter	$83.03	$79.60	$0.31811
Third Quarter	$81.46	$71.96	$0.32151
Fourth Quarter	$79.86	$73.40	$0.33704
2016
First Quarter	$78.53	$68.09	$0.40159
Second Quarter	$81.91	$76.14	$0.18735
Third Quarter	$84.71	$79.63	$0.30039
Fourth Quarter	$88.51	$80.04	$0.14744
2017
First Quarter	$92.27	$87.33	$0.35000
Second Quarter	$93.59	$89.55	$0.32050
Third Quarter	$95.54	$91.58	$0.41000
Fourth Quarter	$101.44	$95.95	$0.45830
2018
First Quarter	$107.43	$96.79	$0.42850
Second Quarter	$104.54	$97.30	$0.40238
Third Quarter	$108.58	$101.80	$0.48592
Fourth Quarter	$106.81	$86.19	$0.53213
2019
First Quarter	$104.84	$89.68	$0.47852
Second Quarter	$108.19	$100.69	$0.49016
Third Quarter	$110.18	$102.40	$0.52010
Fourth Quarter	$115.93	$103.92	$0.46928
2020
First Quarter	$118.71	$71.66	$0.72999
Second Quarter	$113.09	$79.83	$0.42537
Third Quarter	$113.96	$100.38	$0.49662
Fourth Quarter	$127.54	$106.78	$0.44200
2021
First Quarter	$142.80	$125.70	$0.64647
Second Quarter	$152.26	$143.08	$0.42040
Third Quarter	$157.39	$146.61	$0.55680
Fourth Quarter	$163.01	$150.88	$0.45384
2022
First Quarter	$164.20	$148.26	$0.65424
Second Quarter	$158.96	$130.84	$0.70337
Third Quarter	$152.39	$127.28	$0.63024
Fourth Quarter	$149.03	$128.02	$0.57775
2023
First Quarter	$154.96	$137.35	$0.69139
Second Quarter	$149.64	$139.61	$0.64215
Third Quarter	$155.00	$141.04	$0.63761
Fourth Quarter	$158.41	$133.66	$0.60910
2024
First Quarter	$169.37	$153.84	$0.68016
Second Quarter (through April 4, 2024)	$168.37	$165.40	$0.00000

The closing price of the underlying shares on April 4, 2024 was $165.40.

April 2024 PS-11

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

We make no representation as to the amount of dividends, if any, that may be paid on the underlying shares in the future. In any event, as an investor in the securities, you will not be entitled to receive dividends, if any, that may be payable on the underlying shares.

April 2024 PS-12

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

United States Federal Tax Considerations

You should read carefully the discussion under “United States Federal Tax Considerations” and “Risk Factors Relating to the Securities” in the accompanying product supplement and “Summary Risk Factors” in this pricing supplement.

In the opinion of our counsel, Davis Polk & Wardwell LLP, a security should be treated as a prepaid forward contract for U.S. federal income tax purposes. By purchasing a security, you agree (in the absence of an administrative determination or judicial ruling to the contrary) to this treatment. There is uncertainty regarding this treatment, and the IRS or a court might not agree with it. Moreover, our counsel’s opinion is based on market conditions as of the date of this preliminary pricing supplement and is subject to confirmation on the pricing date.

Assuming this treatment of the securities is respected and subject to the discussion in “United States Federal Tax Considerations” in the accompanying product supplement, the following U.S. federal income tax consequences should result under current law:

· You should not recognize taxable income over the term of the securities prior to maturity, other than pursuant to a sale or exchange.

· Upon a sale or exchange of a security (including retirement at maturity), you should recognize gain or loss equal to the difference between the amount realized and your tax basis in the security. Subject to the discussion below concerning the potential application of the “constructive ownership” rules under Section 1260 of the Code, any gain or loss recognized upon a sale, exchange or retirement of a security should be long-term capital gain or loss if you held the security for more than one year.

Even if the treatment of the securities as prepaid forward contracts is respected, your purchase of a security may be treated as entry into a “constructive ownership transaction,” within the meaning of Section 1260 of the Code. In that case, all or a portion of any long-term capital gain you would otherwise recognize in respect of your securities would be recharacterized as ordinary income to the extent such gain exceeded the “net underlying long-term capital gain.” Any long-term capital gain recharacterized as ordinary income under Section 1260 would be treated as accruing at a constant rate over the period you held your securities, and you would be subject to an interest charge in respect of the deemed tax liability on the income treated as accruing in prior tax years. Due to the lack of governing authority under Section 1260, our counsel is not able to opine as to whether or how Section 1260 applies to the securities. You should read the section entitled “United States Federal Tax Considerations—Tax Consequences to U.S. Holders—Securities Treated as Prepaid Forward Contracts—Possible Application of Section 1260 of the Code” in the accompanying product supplement for additional information and consult your tax adviser regarding the potential application of the “constructive ownership” rule.

We do not plan to request a ruling from the IRS regarding the treatment of the securities. An alternative characterization of the securities could materially and adversely affect the tax consequences of ownership and disposition of the securities, including the timing and character of income recognized. In addition, the U.S. Treasury Department and the IRS have requested comments on various issues regarding the U.S. federal income tax treatment of “prepaid forward contracts” and similar financial instruments and have indicated that such transactions may be the subject of future regulations or other guidance. Furthermore, members of Congress have proposed legislative changes to the tax treatment of derivative contracts. Any legislation, Treasury regulations or other guidance promulgated after consideration of these issues could materially and adversely affect the tax consequences of an investment in the securities, possibly with retroactive effect. You should consult your tax adviser regarding possible alternative tax treatments of the securities and potential changes in applicable law.

Non-U.S. Holders. Subject to the discussions below and in “United States Federal Tax Considerations” in the accompanying product supplement, if you are a Non-U.S. Holder (as defined in the accompanying product supplement) of the securities, you generally should not be subject to U.S. federal withholding or income tax in respect of any amount paid to you with respect to the securities, provided that (i) income in respect of the securities is not effectively connected with your conduct of a trade or business in the United States, and (ii) you comply with the applicable certification requirements.

As discussed under “United States Federal Tax Considerations—Tax Consequences to Non-U.S. Holders” in the accompanying product supplement, Section 871(m) of the Code and Treasury regulations promulgated thereunder (“Section 871(m)”) generally impose a 30% withholding tax on dividend equivalents paid or deemed paid to Non-U.S. Holders with respect to certain financial instruments linked to U.S. equities (“U.S. Underlying Equities”) or indices that include U.S. Underlying Equities. Section 871(m) generally applies to instruments that substantially replicate the economic performance of one or more U.S. Underlying Equities, as determined based on tests set forth in the applicable Treasury regulations. However, the regulations, as modified by an IRS notice, exempt financial instruments issued prior to January 1, 2025 that do not have a “delta” of one. Based on the terms of the securities and representations provided by us as of the date of this preliminary pricing supplement, our counsel is of the opinion that the securities should not be treated as transactions that have a “delta” of one within the meaning of the regulations with respect to any U.S. Underlying Equity and, therefore, should not be subject to withholding tax under Section 871(m). However, the final determination regarding the treatment of the securities under Section 871(m) will be made as of the pricing date for the securities, and it is possible that the securities will be subject to withholding tax under Section 871(m) based on the circumstances as of that date.

A determination that the securities are not subject to Section 871(m) is not binding on the IRS, and the IRS may disagree with this treatment. Moreover, Section 871(m) is complex and its application may depend on your particular circumstances, including your other transactions. You should consult your tax adviser regarding the potential application of Section 871(m) to the securities.

If withholding tax applies to the securities, we will not be required to pay any additional amounts with respect to amounts withheld.

You should read the section entitled “United States Federal Tax Considerations” in the accompanying product supplement. The preceding discussion, when read in combination with that section, constitutes the full opinion of Davis Polk & Wardwell LLP regarding the material U.S. federal tax consequences of owning and disposing of the securities.

You should also consult your tax adviser regarding all aspects of the U.S. federal income and estate tax consequences of an investment in the securities and any tax consequences arising under the laws of any state, local or non-U.S. taxing jurisdiction.

April 2024 PS-13

Citigroup Global Markets Holdings Inc.

Trigger Jump Securities Based on the Performance of Shares of the Invesco S&P 500^® Equal Weight ETF Due May , 2026

Principal at Risk Securities

Supplemental Plan of Distribution

CGMI, an affiliate of Citigroup Global Markets Holdings Inc. and the underwriter of the sale of the securities, is acting as principal and will receive an underwriting fee of $25.00 for each $1,000 security sold in this offering. From this underwriting fee, CGMI will pay selected dealers not affiliated with CGMI, including Morgan Stanley Wealth Management, and their financial advisors collectively a fixed selling concession of $20.00 for each $1,000 security they sell. In addition, Morgan Stanley Wealth Management will receive a structuring fee of $5.00 for each security they sell.

The costs included in the original issue price of the securities will include a fee paid by CGMI to LFT Securities, LLC, an entity in which an affiliate of Morgan Stanley Wealth Management has an ownership interest, for providing certain electronic platform services with respect to this offering.

See “Plan of Distribution; Conflicts of Interest” in the accompanying product supplement and “Plan of Distribution” in each of the accompanying prospectus supplement and prospectus for additional information.

Valuation of the Securities

CGMI calculated the estimated value of the securities set forth on the cover page of this pricing supplement based on proprietary pricing models. CGMI’s proprietary pricing models generated an estimated value for the securities by estimating the value of a hypothetical package of financial instruments that would replicate the payout on the securities, which consists of a fixed-income bond (the “bond component”) and one or more derivative instruments underlying the economic terms of the securities (the “derivative component”). CGMI calculated the estimated value of the bond component using a discount rate based on our internal funding rate. CGMI calculated the estimated value of the derivative component based on a proprietary derivative-pricing model, which generated a theoretical price for the instruments that constitute the derivative component based on various inputs, including the factors described under “Summary Risk Factors—The value of the securities prior to maturity will fluctuate based on many unpredictable factors” in this pricing supplement, but not including our or Citigroup Inc.’s creditworthiness. These inputs may be market-observable or may be based on assumptions made by CGMI in its discretionary judgment.

The estimated value of the securities is a function of the terms of the securities and the inputs to CGMI’s proprietary pricing models. As of the date of this preliminary pricing supplement, it is uncertain what the estimated value of the securities will be on the pricing date because it is uncertain what the values of the inputs to CGMI’s proprietary pricing models will be on the pricing date.

For a period of approximately three months following issuance of the securities, the price, if any, at which CGMI would be willing to buy the securities from investors, and the value that will be indicated for the securities on any brokerage account statements prepared by CGMI or its affiliates (which value CGMI may also publish through one or more financial information vendors), will reflect a temporary upward adjustment from the price or value that would otherwise be determined. This temporary upward adjustment represents a portion of the hedging profit expected to be realized by CGMI or its affiliates over the term of the securities. The amount of this temporary upward adjustment will decline to zero on a straight-line basis over the three-month temporary adjustment period. However, CGMI is not obligated to buy the securities from investors at any time. See “Summary Risk Factors—The securities will not be listed on any securities exchange and you may not be able to sell them prior to maturity.”

© 2024 Citigroup Global Markets Inc. All rights reserved. Citi and Citi and Arc Design are trademarks and service marks of Citigroup Inc. or its affiliates and are used and registered throughout the world.

April 2024 PS-14