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, underlying 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 JULY 12, 2024

Citigroup Global Markets Holdings Inc.

July----, 2024 Medium-Term Senior Notes, Series N Pricing Supplement No. 2024-USNCH22642 Filed Pursuant to Rule 424(b)(2) Registration Statement Nos. 333-270327 and 333-270327-01

Partial Principal at Risk Securities Based on the S&P 500^® Index Due August-----, 2027

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 guarantee the full repayment of principal at maturity. Instead, the securities offer the potential for a positive return at maturity based on the performance of the S&P 500^® Index (the “underlying index”) from the initial index level to the final index level, subject to the maximum return at maturity specified below.

▪ The securities offer exposure to a limited range of potential appreciation of the underlying index as described below. However, if the underlying index depreciates from the initial index level to the final index level, you will incur a loss at maturity equal to that depreciation, subject to a maximum loss of 5% of the stated principal amount. Even if the underlying index appreciates from the initial index level to the final index level so that you do receive a positive 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 have achieved on a conventional debt security of ours of comparable maturity.

▪ In exchange for the limited loss potential if the underlying index depreciates, investors in the securities must be willing to forgo (i) any appreciation of the underlying index in excess of the maximum return at maturity specified below and (ii) any dividends that may be paid on the stocks that constitute the underlying index during the 3-year term of the securities. If the underlying index does not appreciate from the pricing date to the valuation date, you will not receive any return on your investment in the securities, and you may lose up to 5% of your investment.

▪ In order to obtain the modified exposure to the underlying 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 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 index:	The S&P 500® Index (ticker symbol: “SPX”)
Aggregate stated principal amount:	$
Stated principal amount:	$1,000.00 per security
Pricing date:	July     , 2024 (expected to be July 31, 2024)
Issue date:	August     , 2024 (expected to be August 5, 2024).
Valuation date:	July     , 2027 (expected to be July 30, 2027), subject to postponement if such date is not a scheduled trading day or if certain market disruption events occur
Maturity date:	August     , 2027 (expected to be August 4, 2027)
Payment at maturity:	For each $1,000.00 stated principal amount security you hold at maturity: ▪If the final index level is greater than the initial index level: $1,000.00 + ($1,000.00 × the index return), subject to the maximum return at maturity ▪If the final index level is less than or equal to the initial index level: $1,000.00 + ($1,000.00 × the index return), subject to the minimum payment at maturity If the final index level depreciates from the initial index level, you will be exposed to the first 5% of that depreciation and your payment at maturity will be less than the stated principal amount per security. You should not invest in the securities unless you are willing and able to bear the risk of losing up to $50.00 per security.
Initial index level:	, the closing level of the underlying index on the pricing date
Final index level:	The closing level of the underlying index on the valuation date
Index return:	(i) The final index level minus the initial index level, divided by the (ii) initial index level
Maximum return at maturity:	$240.50 per security (24.05% of the stated principal amount). The payment at maturity per security will not exceed $1,000.00 plus the maximum return at maturity.
Minimum payment at maturity:	$950.00 per security (95.00% of the stated principal amount).
Listing:	The securities will not be listed on any securities exchange
CUSIP / ISIN:	17332MEG5 / US17332MEG50
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		$25.00(2)	$970.00
			$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 $913.00 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 $30.00 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 $25.00 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 nor any state securities commission has approved or disapproved of the securities or determined that this pricing supplement and the accompanying product supplement, underlying supplement, prospectus supplement and prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

You should read this pricing supplement together with the accompanying product supplement, underlying supplement, prospectus supplement and prospectus, each of which can be accessed via the hyperlinks below:

Product Supplement No. EA-02-10 dated March 7, 2023Underlying Supplement No. 11 dated March 7, 2023Prospectus 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.

Partial Principal at Risk Securities Based on the S&P 500^® Index Due August -----, 2027

Additional Information

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. 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” and “Description of the Securities—Certain Additional Terms for Securities Linked to an Underlying Index—Discontinuance or Material Modification of an Underlying Index,” and not in this pricing supplement. The accompanying underlying supplement contains important disclosures regarding the underlying index that are not repeated in this pricing supplement. It is important that you read the accompanying product supplement, underlying supplement, prospectus supplement and prospectus together with this pricing supplement before deciding whether to invest in the securities. Certain terms used but not defined in this pricing supplement are defined in the accompanying product supplement.

July 2024 PS-2

Citigroup Global Markets Holdings Inc.

Partial Principal at Risk Securities Based on the S&P 500^® Index Due August -----, 2027

Investment Summary

The securities provide investors:

▪ an opportunity to gain exposure to the underlying index, subject to the maximum return at maturity, within a limited range of positive performance; and

▪ a limited loss potential of up to 5% at maturity.

At maturity, if the underlying index depreciates from the initial index level to the final index level, you will incur a loss equal to that depreciation, subject to a maximum loss of 5% of the stated principal amount. All payments on the securities are subject to the credit risk of Citigroup Global Markets Holdings Inc. and Citigroup Inc. Investors in the securities will not receive any dividends paid on the stocks that constitute the underlying index over the term of the securities.

Maturity:	Approximately 3 years
Maximum return at maturity:	$240.50 per security (24.05% of the stated principal amount)
Minimum payment at maturity:	$950.00 per security
Interest:	None

Key Investment Rationale

The securities offer investors exposure to the performance of the underlying index, provided that investors will not receive a payment at maturity in excess of the maximum payment at maturity, which will be $1,240.50 per security, and provide for a limited loss potential of up to 5% at maturity. They are for investors who are concerned about principal risk but seek an equity index-based return, and who are willing to forgo dividends in exchange for the limited loss potential of up to 5% at maturity if the underlying index depreciates.

Limited Loss Potential:	The securities offer investors exposure to appreciation of the underlying index within a limited range of positive performance, while providing for limited loss potential at maturity.
Upside Scenario:	If the final index level is greater than the initial index level, the payment at maturity for each security will be equal to the $1,000.00 stated principal amount plus the product of (i) the stated principal amount and (ii) the index return, subject to the maximum return at maturity.
Downside Scenario:	If the final index level is less than the initial index level, the securities will be exposed to the negative performance of the underlying index, subject to a maximum loss of 5% of the stated principal amount.

July 2024 PS-3

Citigroup Global Markets Holdings Inc.

Partial Principal at Risk Securities Based on the S&P 500^® Index Due August -----, 2027

Hypothetical Examples

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

Investors in the securities will not receive any dividends that may be paid on the stocks that constitute the underlying index. 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 index or the stocks that constitute the underlying index” below.

Partial Principal at Risk SecuritiesPayment at Maturity Diagram
n The Securities	n The Underlying Index

The examples below are based on the hypothetical initial index level of 100.00 and do not reflect the actual initial index level. For the actual initial index level, see the cover page of this pricing supplement. We have used this hypothetical value, rather than the actual value, 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 index level and not the hypothetical value indicated below. For ease of analysis, figures below may have been rounded.

Example 1—Upside Scenario A. The hypothetical final index level is 105.00 (a 5.00% increase from the hypothetical initial index level), which is greater than the hypothetical initial index level.

Payment at maturity per security = $1,000 + ($1,000 × the index return), subject to the maximum return at maturity of $240.50 per security

= $1,000 + ($1,000 × 5.00%), subject to the maximum return at maturity of $240.50 per security

= $1,000 + $50.00, subject to the maximum return at maturity of $240.50 per security

= $1.050.00

July 2024 PS-4

Citigroup Global Markets Holdings Inc.

Partial Principal at Risk Securities Based on the S&P 500^® Index Due August -----, 2027

Because the underlying index appreciated by 5.00% from its hypothetical initial index level to its hypothetical final index level, your total return at maturity in this scenario would be 5%.

Example 2—Upside Scenario B. The hypothetical final index level is 190.00 (a 90.00% increase from the hypothetical initial index level), which is greater than the hypothetical initial index level.

Payment at maturity per security = $1,000 + ($1,000 × the index return), subject to the maximum return at maturity of $240.50 per security

= $1,000 + ($1,000 × 90.00%), subject to the maximum return at maturity of $240.50 per security

= $1,000 + $900.00, subject to the maximum return at maturity of $240.50 per security

= $1,240.50

Because the underlying index appreciated from its hypothetical initial index level to its hypothetical final index level and the index return is greater than the maximum return at maturity, your payment at maturity in this scenario would equal the maximum payment at maturity of $1,240.50 per security. 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 index without a maximum return.

Example 3—Downside Scenario A. The hypothetical final index level is 97.50 (a 2.50% decrease from the hypothetical initial index level), which is less than the hypothetical initial index level.

Payment at maturity per security = $1,000 + ($1,000 × the index return), subject to the minimum payment at maturity of $950.00 per security

= $1,000 + ($1,000 × -2.50%), subject to the minimum payment at maturity of $950.00 per security

= $1,000 + -$25.00, subject to the minimum payment at maturity of $950.00 per security

= $975.00, subject to the minimum payment at maturity of $950.00 per security

= $975.00

Because the underlying index depreciated from its hypothetical initial index level to its hypothetical final index level, but not by more than 5.00%, your payment at maturity would reflect 1-to-1 exposure to the negative performance of the underlying index and you would incur a loss at maturity of 2.50%.

Example 4—Downside Scenario B. The hypothetical final index level is 80.00 (a 20.00% decrease from the hypothetical initial index level), which is less than the hypothetical initial index level.

Payment at maturity per security = $1,000 + ($1,000 × the index return), subject to the minimum payment at maturity of $950.00 per security

= $1,000 + ($1,000 × -20.00%), subject to the minimum payment at maturity of $950.00 per security

= $1,000 + -$200.00, subject to the minimum payment at maturity of $950.00 per security

= $800.00, subject to the minimum payment at maturity of $950.00 per security

= $950.00

Because the underlying index depreciated from its hypothetical initial index level to its hypothetical final index level by more than 5.00%, you would incur a loss at maturity equal to the maximum loss of 5.00%.

July 2024 PS-5

Citigroup Global Markets Holdings Inc.

Partial Principal at Risk Securities Based on the S&P 500^® Index Due August -----, 2027

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 index. 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.

▪ You may not receive any return on your investment in the securities and you may lose up to 5% of your investment. You will receive a positive return on your investment in the securities only if the underlying index appreciates from the initial index level to the final index level. If the final index level is less than the initial index level, you will lose 1% of the stated principal amount of the securities for every 1% by which the final index level is less than the initial index level, subject to a maximum loss of 5% of your investment. As the securities do not pay any interest, if the underlying index does not appreciate sufficiently from the initial index level to the final index level over the term of the securities, there is no assurance that your total return at maturity on the securities will be as great as could have been achieved on conventional debt securities of ours of comparable maturity. Additionally, you may lose up to 5% of your investment.

▪ 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.

▪ Although the securities limit your loss at maturity to 5%, you may nevertheless suffer additional losses on your investment in real value terms if the underlying index declines or does not appreciate sufficiently from the initial index level to the final index level. This is because inflation may cause the real value of the stated principal amount to be less at maturity than it is at the time you invest, and because an investment in the securities represents a forgone opportunity to invest in an alternative asset that does generate a positive real return. This potential loss in real value terms is significant given the 3-year term of the securities. You should carefully consider whether an investment that may not provide for any return on your investment, or may provide a return that is lower than the return on alternative investments, is appropriate for you.

▪ Your potential return on the securities is limited. Your potential total return on the securities at maturity is limited to the maximum return at maturity of 24.05%, which is equivalent to a maximum return at maturity of $240.50 per security and would result in a maximum payment at maturity of $1,240.50 per security.

▪ Investing in the securities is not equivalent to investing in the underlying index or the stocks that constitute the underlying index. You will not have voting rights, rights to receive dividends or other distributions or any other rights with respect to the stocks that constitute the underlying index.

▪ Your payment at maturity depends on the closing level of the underlying index on a single day. Because your payment at maturity depends on the closing level of the underlying index solely on the valuation date, you are subject to the risk that the closing level of the underlying index 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 stocks that constitute the underlying index or in another instrument linked to the underlying index 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 the closing levels of the underlying index throughout the term of the securities, 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 anything 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 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

July 2024 PS-6

Citigroup Global Markets Holdings Inc.

Partial Principal at Risk Securities Based on the S&P 500^® Index Due August -----, 2027

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 index, dividend yields on the stocks that constitute the underlying index 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 level and volatility of the underlying index and a number of other factors, including the price and volatility of the stocks that constitute the underlying index, the dividend yields on the stocks that constitute the underlying index, 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 level of the underlying index may not result in a comparable change in the value of your 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

July 2024 PS-7

Citigroup Global Markets Holdings Inc.

Partial Principal at Risk Securities Based on the S&P 500^® Index Due August -----, 2027

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 index. The fact that we are offering the securities does not mean that we believe that investing in an instrument linked to the underlying index 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 stocks that constitute the underlying index or in instruments related to the underlying index or such stocks, and may publish research or express opinions, that in each case are inconsistent with an investment linked to the underlying index. These and other activities of our affiliates may affect the level of the underlying index in a way that has a negative impact on your interests as a holder of the securities.

▪ The level of the underlying index 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 stocks that constitute the underlying index and other financial instruments related to the underlying index or such stocks and may adjust such positions during the term of the securities. Our affiliates also trade the stocks that constitute the underlying index and other financial instruments related to the underlying index or such stocks 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 level of the underlying index 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 issuers of the stocks that constitute the underlying index, 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 such issuer that are available to them without regard to your interests.

▪ The calculation agent, which is an affiliate of ours, will make important determinations with respect to the securities. If certain events occur, such as market disruption events or the discontinuance of the underlying index, CGMI, as calculation agent, will be required to make discretionary judgments that could significantly affect your payment at maturity. 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.

▪ Adjustments to the underlying index may affect the value of your securities. S&P Dow Jones Indices LLC (the “underlying index publisher”) may add, delete or substitute the stocks that constitute the underlying index or make other methodological changes that could affect the level of the underlying index. The underlying index publisher may discontinue or suspend calculation or publication of the underlying index at any time without regard to your interests as holders of the securities.

July 2024 PS-8

Citigroup Global Markets Holdings Inc.

Partial Principal at Risk Securities Based on the S&P 500^® Index Due August -----, 2027

Information About the S&P 500^® Index

The S&P 500^® Index consists of the common stocks of 500 issuers selected to provide a performance benchmark for the large capitalization segment of the U.S. equity markets. It is calculated and maintained by S&P Dow Jones Indices LLC. The S&P 500^® Index is reported by Bloomberg L.P. under the ticker symbol “SPX.”

“Standard & Poor’s,” “S&P” and “S&P 500^®” are trademarks of Standard & Poor’s Financial Services LLC and have been licensed for use by Citigroup Inc. and its affiliates. For more information, see “Equity Index Descriptions—The S&P U.S. Indices—License Agreement” in the accompanying underlying supplement.

Please refer to the section “Equity Index Descriptions—The S&P U.S. Indices” in the accompanying underlying supplement for important disclosures regarding the S&P 500^® Index.

Historical Information

The closing level of the underlying index on July 11, 2024 was 5,584.54.

The graph below shows the closing level of the underlying index for each day such level was available from January 2, 2014 to July 11, 2024. We obtained the closing levels from Bloomberg L.P., without independent verification. You should not take the historical levels of the underlying index as an indication of future performance.

S&P 500^® Index – Historical Closing Levels
January 2, 2014 to July 11, 2024

July 2024 PS-9

Citigroup Global Markets Holdings Inc.

Partial Principal at Risk Securities Based on the S&P 500^® Index Due August -----, 2027

United States Federal Tax Considerations

Prospective investors should note that the section entitled “United States Federal Tax Considerations” in the accompanying product supplement does not apply to the securities issued under this pricing supplement and is superseded by the following discussion.

In the opinion of our counsel, Davis Polk & Wardwell LLP, which is based on current market conditions, the securities should be treated as “contingent payment debt instruments” for U.S. federal income tax purposes, as described in the section of the accompanying prospectus supplement called “United States Federal Tax Considerations—Tax Consequences to U.S. Holders—Notes Treated as Contingent Payment Debt Instruments,” and the remaining discussion is based on this treatment.

If you are a U.S. Holder (as defined in the accompanying prospectus supplement), you will be required to recognize interest income during the term of the securities at the “comparable yield,” which generally is the yield at which we could issue a fixed-rate debt instrument with terms similar to those of the securities, including the level of subordination, term, timing of payments and general market conditions, but excluding any adjustments for the riskiness of the contingencies or the liquidity of the securities. We are required to construct a “projected payment schedule” in respect of the securities representing a payment the amount and timing of which would produce a yield to maturity on the securities equal to the comparable yield. Assuming you hold the securities until their maturity, the amount of interest you include in income based on the comparable yield in the taxable year in which the securities mature will be adjusted upward or downward to reflect the difference, if any, between the actual and projected payment on the securities at maturity as determined under the projected payment schedule.

Upon the sale, exchange or retirement of the securities prior to maturity, you generally will recognize gain or loss equal to the difference between the proceeds received and your adjusted tax basis in the securities. Your adjusted tax basis will equal your purchase price for the securities, increased by interest previously included in income on the securities. Any gain generally will be treated as ordinary income, and any loss generally will be treated as ordinary loss to the extent of prior interest inclusions on the security and as capital loss thereafter.

We have determined that the comparable yield for a security is a rate of %, compounded semi-annually, and that the projected payment schedule with respect to a security consists of a single payment of $ at maturity.

Neither the comparable yield nor the projected payment schedule constitutes a representation by us regarding the actual amount that we will pay on the securities.

Non-U.S. Holders. Subject to the discussions below regarding Section 871(m) and in “United States Federal Tax Considerations—Tax Consequences to Non-U.S. Holders” and “—FATCA” in the accompanying prospectus supplement, if you are a Non-U.S. Holder (as defined in the accompanying prospectus supplement) of the securities, under current law you generally will not be subject to U.S. federal withholding or income tax in respect of any payment on or any amount received on the sale, exchange or retirement of 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. See “United States Federal Tax Considerations—Tax Consequences to Non-U.S. Holders” in the accompanying prospectus supplement for a more detailed discussion of the rules applicable to Non-U.S. Holders of the securities.

As discussed under “United States Federal Tax Considerations—Tax Consequences to Non-U.S. Holders” in the accompanying prospectus supplement, Section 871(m) of the Internal Revenue Code of 1986, as amended, 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 (“Underlying Securities”) or indices that include Underlying Securities. Section 871(m) generally applies to instruments that substantially replicate the economic performance of one or more Underlying Securities, as determined based on tests set forth in the applicable Treasury regulations. However, the regulations, as modified by an Internal Revenue Service (“IRS”) notice, exempt financial instruments issued prior to January 1, 2027 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 Underlying Security 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 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.

July 2024 PS-10

Citigroup Global Markets Holdings Inc.

Partial Principal at Risk Securities Based on the S&P 500^® Index Due August -----, 2027

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 prospectus 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 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.

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 $30.00 for each $1,000.00 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 $25.00 for each $1,000.00 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.”

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July 2024 PS-11