[424B2] Citigroup Inc. Prospectus Supplement

Rhea-AI Filing Summary

Citigroup Global Markets Holdings Inc. (guaranteed by Citigroup Inc.) is marketing a new structured note: “Autocallable Contingent Coupon Equity-Linked Securities Linked to the Worst Performing of Broadcom Inc. (AVGO) and Palo Alto Networks Inc. (PANW), due 26 Jan 2027.” The $1,000-denominated senior unsecured notes offer a contingent coupon rate of at least 10.25% p.a. (paid quarterly at ≥2.5625% per period) but only if, on the relevant valuation date, the worst-performing share closes at or above its coupon barrier of 59% of its initial level. Any skipped coupons can “catch up” if the barrier is later met, but coupons missed through final valuation are permanently forfeited.

Principal repayment is conditional. If the securities are not automatically called, holders receive at maturity:

• $1,000 plus final coupon if the worst-performing share is ≥ its final buffer value (also 59% of initial).
• A fixed number of worst-performing shares (or cash equivalent) if the final level is <59% of initial. This may be worth far less than $1,000 and could be $0 if the share price collapses.

Automatic early redemption (autocall) is possible on any of five quarterly dates starting 16 Oct 2025 if the worst-performing share is ≥ its initial level; investors then receive $1,000 plus the due coupon, ending the trade early and limiting upside.

Key initial terms (set 10 Jul 2025): AVGO initial $275.40, PANW initial $192.07; coupon/ buffer levels fixed at 59% of each. The preliminary estimated value on the pricing date is expected to be ≥$928.50, below the $1,000 issue price, reflecting distribution fees ($12.50) and internal funding spread.

Risks highlighted: (1) up to 100% capital loss if the worst performer drops >41%; (2) no guarantee of any coupon; (3) credit risk of both CGMHI and Citigroup Inc.; (4) liquidity risk—no exchange listing and discretionary secondary market only through CGMI; (5) potential conflicts as CGMI is issuer, underwriter, calculation agent and hedger; (6) complex U.S. tax treatment and potential 30% withholding for non-U.S. investors; (7) estimated value and secondary bid likely well below issue price due to hedging costs and bid–ask spread.

For investors seeking enhanced yield relative to plain-vanilla Citigroup senior debt, the note provides double-digit income potential and 41% downside buffer, but only by taking correlated single-stock equity risk, autocall truncation risk and issuer credit exposure. The security is therefore suitable solely for sophisticated investors who can tolerate equity-level volatility and illiquidity for up to 18 months.

Positive

• Double-digit potential yield (≥10.25% p.a.) provides significantly higher income than comparable conventional Citi senior debt with similar tenor.
• 41% downside buffer protects principal unless the worst-performing share falls below 59% of its initial level.
• Catch-up feature allows previously missed coupons to be recovered if the barrier is later met.
• Early autocall returns capital quickly in strong equity scenarios, reducing duration risk.

Negative

• Full principal at risk; worst-performing share drop below 59% leads to share delivery worth less than $1,000, potentially zero.
• Conditional income; coupons skipped whenever the barrier is breached may result in no yield for entire term.
• Issuer and guarantor credit risk; repayment depends on Citigroup Global Markets Holdings Inc. and Citigroup Inc. performance.
• Illiquidity; no exchange listing and discretionary secondary market likely at steep discount to issue price.
• Structuring cost; estimated value (≥$928.50) materially below $1,000 issue price, creating an immediate mark-to-market drag.
• Complex taxation; uncertain U.S. federal tax treatment and possible 30% withholding for non-U.S. holders.
• Autocall limits upside; strong share performance results in early redemption, capping total return.

Insights

Structured Products Analyst

TL;DR: High coupon & 41% buffer attractive, but principal is fully at risk and coupons are conditional; product suits yield-seeking, risk-tolerant buyers.

The note embeds a worst-of two-stock digital coupon and physical share settlement put option. The 10.25% headline yield is financed by selling downside beyond 41% and by giving Citigroup cheap call optionality via the autocall. Volatility and low correlation between AVGO and PANW increase skip-coupon probability and decrease expected return vs. headline. The indicative value (~$928.50) implies a c.7.2% structuring/hedging spread versus issue price, so investors transfer that economic edge to Citi on day one. Because the securities are senior debt, any deterioration in Citi’s credit spreads will erode secondary pricing even if stocks are flat. Overall impact for investors: risk-reward balanced toward yield seekers; for Citigroup equity investors: immaterial.

Credit & Risk Specialist

TL;DR: Product adds incremental, but immaterial, funding for Citigroup; buyers face layered credit, market and liquidity risks.

CGMHI achieves sub-institutional funding at a spread tighter than comparable senior notes by embedding equity-linked features. From a treasury standpoint, issuance is routine and not transformative, hence neutral to Citigroup credit metrics. For noteholders, the multiple underlyings amplify tail risk: only one stock needs to breach the 59% floor to trigger share delivery. Historical 10-year drawdowns show AVGO at –55% and PANW at –66%, both inside the loss zone. Illiquidity is significant: no listing, CGMI sole dealer, three-month bid premium decay. Tax complexity (Section 871(m) uncertainty) creates withholding risk for non-U.S. investors. Rating: neutral overall.

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 JULY 14, 2025

Citigroup Global Markets Holdings Inc.

July     , 2025 Medium-Term Senior Notes, Series N Pricing Supplement No. 2025-USNCH[  ] Filed Pursuant to Rule 424(b)(2) Registration Statement Nos. 333-270327 and 333-270327-01

Autocallable Contingent Coupon Equity Linked Securities Linked to the Worst Performing of Broadcom Inc. and Palo Alto Networks, Inc. Due January 26, 2027

▪ The securities offered by this pricing supplement are unsecured debt securities issued by Citigroup Global Markets Holdings Inc. and guaranteed by Citigroup Inc. The securities offer the potential for periodic contingent coupon payments at an annualized rate that, if all are paid, would produce a yield that is generally higher than the yield on our conventional debt securities of the same maturity. In exchange for this higher potential yield, you must be willing to accept the risks that (i) your actual yield may be lower than the yield on our conventional debt securities of the same maturity because you may not receive one or more, or any, contingent coupon payments, (ii) the value of what you receive at maturity may be significantly less than the stated principal amount of your securities, and may be zero, and (iii) the securities may be automatically called for redemption prior to maturity beginning on the first potential autocall date specified below. Each of these risks will depend solely on the performance of the worst performing of the underlyings specified below.

▪ You will be subject to risks associated with each of the underlyings and will be negatively affected by adverse movements in any one of the underlyings. Although you will have downside exposure to the worst performing underlying, you will not receive dividends with respect to any underlying or participate in any appreciation of any underlying.

▪ Investors in the securities must be willing to accept (i) an investment that may have limited or no liquidity and (ii) the risk of not receiving any payments 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.

Underlyings:	Underlying	Initial underlying value*	Coupon barrier value**	Final buffer value**	Equity ratio***
	Broadcom Inc.	$275.40	$162.486	$162.486	6.15438
	Palo Alto Networks, Inc.	$192.07	$113.321	$113.321	8.82449

	*For each underlying, its closing value on the strike date **For each underlying, 59.00% of its initial underlying value ***For each underlying, the stated principal amount divided by its final buffer value
Stated principal amount:	$1,000 per security
Strike date:	July 10, 2025
Pricing date:	July 16, 2025
Issue date:	July 23, 2025
Valuation dates:	October 16, 2025, January 16, 2026, April 16, 2026, July 16, 2026, October 16, 2026 and January 19, 2027 (the “final valuation date”), each subject to postponement if such date is not a scheduled trading day or certain market disruption events occur
Maturity date:	Unless earlier redeemed, January 26, 2027
Contingent coupon payment dates:	The fifth business day after each valuation date, except that the contingent coupon payment date following the final valuation date will be the maturity date
Contingent coupon:	On each contingent coupon payment date, unless previously redeemed, the securities will pay a contingent coupon equal to at least 2.5625% of the stated principal amount of the securities (equivalent to a contingent coupon rate of at least 10.25% per annum) (to be determined on the pricing date) if and only if the closing value of the worst performing underlying on the immediately preceding valuation date is greater than or equal to its coupon barrier value. If the closing value of the worst performing underlying on any valuation date is less than its coupon barrier value, you will not receive any contingent coupon payment on the immediately following contingent coupon payment date. If the closing value of the worst performing underlying on one or more valuation dates is less than its coupon barrier value and, on a subsequent valuation date, the closing value of the worst performing underlying on that subsequent valuation date is greater than or equal to its coupon barrier value, your contingent coupon payment for that subsequent valuation date will include all previously unpaid contingent coupon payments (without interest on amounts previously unpaid). However, if the closing value of the worst performing underlying on a valuation date is less than its coupon barrier value and the closing value of the worst performing underlying on each subsequent valuation date up to and including the final valuation date is less than its coupon barrier value, you will not receive the unpaid contingent coupon payments in respect of those valuation dates.
Payment at maturity:	If the securities are not automatically redeemed prior to maturity, you will receive at maturity for each security you then hold (in addition to the final contingent coupon payment, if applicable): § If the final underlying value of the worst performing underlying on the final valuation date is greater than or equal to its final buffer value: $1,000 § If the final underlying value of the worst performing underlying on the final valuation date is less than its final buffer value: a fixed number of underlying shares of the worst performing underlying on the final valuation date equal to its equity ratio (or, if we elect, the cash value of those shares based on its final underlying value) If the securities are not automatically redeemed prior to maturity and the final underlying value of the worst performing underlying on the final valuation date is less than its final buffer value, you will receive underlying shares of the worst performing underlying on the final valuation date (or, in our sole discretion, cash) that will be worth less than the stated principal amount of your securities, and possibly nothing, at maturity, and you will not receive any contingent coupon payment at maturity (including any previously unpaid contingent coupon payments).
Listing:	The securities will not be listed on any securities exchange
Underwriter:	Citigroup Global Markets Inc. (“CGMI”), an affiliate of the issuer, acting as principal
Underwriting fee and issue price:	Issue price(1)	Underwriting fee(2)	Proceeds to issuer
Per security:	$1,000.00	$12.50	$987.50
Total:	$	$	$

(Key Terms continued on next page)

(1) Citigroup Global Markets Holdings Inc. currently expects that the estimated value of the securities on the pricing date will be at least $928.50 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) For more information on the distribution of the securities, see “Supplemental Plan of Distribution” in this pricing supplement. In addition to the underwriting fee, CGMI and its affiliates 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.

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-04-10 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.

KEY TERMS (continued)
Automatic early redemption:	If, on any potential autocall date, the closing value of the worst performing underlying on that potential autocall date is greater than or equal to  its initial underlying value, each security you then hold will be automatically called on that potential autocall date for redemption on the immediately following contingent coupon payment date for an amount in cash equal to $1,000.00 plus the related contingent coupon payment. The automatic early redemption feature may significantly limit your potential return on the securities. If the worst performing underlying performs in a way that would otherwise be favorable, the securities are likely to be automatically called for redemption prior to maturity, cutting short your opportunity to receive contingent coupon payments. The securities may be automatically called for redemption as early as the first potential autocall date specified below.
Potential autocall dates:	The valuation dates scheduled to occur on October 16, 2025, January 16, 2026, April 16, 2026, July 16, 2026 and October 16, 2026
Final underlying value:	For each underlying, its closing value on the final valuation date
Worst performing underlying:	For any valuation date, the underlying with the lowest underlying return determined as of that valuation date
Underlying return:	For each underlying on any valuation date, (i) its closing value on that valuation date minus its initial underlying value, divided by (ii) its initial underlying value
CUSIP / ISIN:	17333H7A6 / US17333H7A60

PS-2

Citigroup Global Markets Holdings Inc.

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, the accompanying product supplement contains important information about how the closing value of each underlying will be determined and about adjustments that may be made to the terms of the securities upon the occurrence of market disruption events and other specified events with respect to each underlying. 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.

Closing Value. The “closing value” of each underlying on any date is the closing price of its underlying shares on such date, as provided in the accompanying product supplement. The “underlying shares” of the underlyings are their respective shares of common stock. Please see the accompanying product supplement for more information.

PS-3

Citigroup Global Markets Holdings Inc.

Hypothetical Examples

The examples in the first section below illustrate how to determine whether a contingent coupon will be paid (and whether any previously unpaid contingent coupon payments will be paid) and whether the securities will be automatically called for redemption following a valuation date that is also a potential autocall date. The examples in the second section below illustrate how to determine the payment at maturity on the securities, assuming the securities are not automatically redeemed prior to maturity. The examples are solely for illustrative purposes, do not show all possible outcomes and are not a prediction of any payment that may be made on the securities.

The examples below are based on the following hypothetical values and do not reflect the actual initial underlying values, coupon barrier values, final buffer values or equity ratios of the underlyings. For the actual initial underlying value, coupon barrier value, final buffer value and equity ratio of each underlying, 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 payments on the securities will be calculated based on the actual initial underlying value, coupon barrier value, final buffer value and equity ratio of each underlying, and not the hypothetical values indicated below. For ease of analysis, figures below have been rounded. The examples below assume that the contingent coupon rate is set at the lowest value indicated on the cover page of this pricing supplement. The actual contingent coupon rate will be determined on the pricing date.

Underlying	Hypothetical initial underlying value	Hypothetical coupon barrier value	Hypothetical final buffer value	Hypothetical equity ratio
Broadcom Inc.	$100.00	$59.00 (59.00% of its hypothetical initial underlying value)	$59.00 (59.00% of its hypothetical initial underlying value)	16.94915
Palo Alto Networks, Inc.	$100.00	$59.00 (59.00% of its hypothetical initial underlying value)	$59.00 (59.00% of its hypothetical initial underlying value)	16.94915

Hypothetical Examples of Contingent Coupon Payments and any Payment upon Automatic Early Redemption Following a Valuation Date that is also a Potential Autocall Date

The three hypothetical examples below illustrate how to determine whether a contingent coupon will be paid and whether the securities will be automatically redeemed following a hypothetical valuation date that is also a potential autocall date, assuming that the closing values of the underlyings on the hypothetical valuation date are as indicated below.

	Hypothetical closing value of Broadcom Inc. on hypothetical valuation date	Hypothetical closing value of Palo Alto Networks, Inc. on hypothetical valuation date	Hypothetical payment per $1,000 security on related contingent coupon payment date
Example 1 Hypothetical Valuation Date #1	$120 (underlying return = ($120 - $100) / $100 = 20%)	$85 (underlying return = ($85 - $100) / $100 = -15%)	$25.625 (contingent coupon is paid; securities not redeemed)
Example 2 Hypothetical Valuation Date #2	$45 (underlying return = ($45 - $100) / $100 = -55%)	$120 (underlying return = ($120 - $100) / $100 = 20%)	$0.00 (no contingent coupon; securities not redeemed)
Example 3 Hypothetical Valuation Date #3	$110 (underlying return = ($110 - $100) / $100 = 10%)	$115 (underlying return = ($115 - $100) / $100 = 15%)	$1,051.25 (contingent coupon plus the previously unpaid contingent coupon is paid; securities redeemed)

Example 1: On hypothetical valuation date #1, Palo Alto Networks, Inc. has the lowest underlying return and, therefore, is the worst performing underlying on the hypothetical valuation date. In this scenario, the closing value of the worst performing underlying on the hypothetical valuation date is greater than its coupon barrier value but less than its initial underlying value. As a result, investors in the securities would receive the contingent coupon payment on the related contingent coupon payment date and the securities would not be automatically redeemed.

Example 2: On hypothetical valuation date #2, Broadcom Inc. has the lowest underlying return and, therefore, is the worst performing underlying on the hypothetical valuation date. In this scenario, the closing value of the worst performing underlying on the hypothetical valuation date is less than its coupon barrier value. As a result, investors would not receive any payment on the related contingent coupon payment date and the securities would not be automatically redeemed.

Investors in the securities will not receive a contingent coupon on the contingent coupon payment date following a valuation date if the closing value of the worst performing underlying on that valuation date is less than its coupon barrier value. Whether a contingent coupon is paid following a valuation date depends solely on the closing value of the worst performing underlying on that valuation date.

Example 3: On hypothetical valuation date #3, Broadcom Inc. has the lowest underlying return and, therefore, is the worst performing underlying on the hypothetical valuation date. In this scenario, the closing value of the worst performing underlying on the hypothetical valuation date is greater than both its coupon barrier value and its initial underlying value. As a result, the securities would be automatically redeemed on the related contingent coupon payment date for an amount in cash equal to $1,000.00 plus the related contingent coupon payment plus any previously unpaid contingent coupon payments. Because no contingent coupon payment was received in connection with hypothetical valuation date #2, investors in the securities would also receive the previously unpaid contingent coupon payment on the related contingent coupon payment date.

If the hypothetical valuation date were not also a potential autocall date, the securities would not be automatically redeemed on the related contingent coupon payment date.

PS-4

Citigroup Global Markets Holdings Inc.

Hypothetical Examples of the Payment at Maturity on the Securities

The next three hypothetical examples illustrate the calculation of the payment at maturity on the securities, assuming that the securities have not been earlier automatically redeemed and that the final underlying values of the underlyings are as indicated below.

	Hypothetical final underlying value of Broadcom Inc.	Hypothetical final underlying value of Palo Alto Networks, Inc.	Hypothetical payment at maturity per $1,000 security
Example 4	$110 (underlying return = ($110 - $100) / $100 = 10%)	$120 (underlying return = ($120 - $100) / $100 = 20%)	$1,025.625 plus any previously unpaid contingent coupon payments
Example 5	$110 (underlying return = ($110 - $100) / $100 = 10%)	$30 (underlying return = ($30 - $100) / $100 = -70%)	A number of underlying shares of the worst performing underlying on the final valuation date (or, in our sole discretion, cash) worth approximately $508.47 based on its final underlying value
Example 6	$0 (underlying return = ($0 - $100) / $100 = -100%)	$40 (underlying return = ($40 - $100) / $100 = -60%)	$0.00

Example 4: On the final valuation date, Broadcom Inc. has the lowest underlying return and, therefore, is the worst performing underlying on the final valuation date. In this scenario, the final underlying value of the worst performing underlying on the final valuation date is greater than its final buffer value. Accordingly, at maturity, you would receive the stated principal amount of the securities plus the contingent coupon payment due at maturity (assuming no previously unpaid contingent coupon payments), but you would not participate in the appreciation of any of the underlyings.

Example 5: On the final valuation date, Palo Alto Networks, Inc. has the lowest underlying return and, therefore, is the worst performing underlying on the final valuation date. In this scenario, the final underlying value of the worst performing underlying on the final valuation date is less than its final buffer value. Accordingly, at maturity, you would receive for each security you then hold a fixed number of underlying shares of the worst performing underlying on the final valuation date equal to its equity ratio (or, at our option, the cash value thereof).

In this scenario, the value of a number of underlying shares of the worst performing underlying on the final valuation date equal to its equity ratio, based on its final underlying value, would be approximately $508.47. Therefore, the value of the underlying shares of the worst performing underlying on the final valuation date (or, in our discretion, cash) you receive at maturity would be significantly less than the stated principal amount of your securities. You would incur a loss based on the performance of the worst performing underlying on the final valuation date. In addition, because the final underlying value of the worst performing underlying on the final valuation date is below its coupon barrier value, you would not receive any contingent coupon payment (including any previously unpaid contingent coupon payments) at maturity.

If the final underlying value of the worst performing underlying on the final valuation date is less than its final buffer value, we will have the option to deliver to you on the maturity date either a number of underlying shares of the worst performing underlying on the final valuation date equal to its equity ratio or the cash value of those underlying shares based on their final underlying value. The value of those underlying shares on the maturity date may be different than their final underlying value.

Example 6: On the final valuation date, Broadcom Inc. has the lowest underlying return and, therefore, is the worst performing underlying on the final valuation date. In this scenario, the underlying shares of the worst performing underlying on the final valuation date are worthless and you would lose your entire investment in the securities at maturity. In addition, because the final underlying value of the worst performing underlying on the final valuation date is below its coupon barrier value, you would not receive any contingent coupon payment at maturity.

It is possible that the closing value of the worst performing underlying will be less than its coupon barrier value on each valuation date and less than its final buffer value on the final valuation date, such that you will not receive any contingent coupon payments over the term of the securities (including any previously unpaid contingent coupon payments) and will receive less than the stated principal amount of your securities, and possibly nothing, at maturity.

PS-5

Citigroup Global Markets Holdings Inc.

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 (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 each underlying. Accordingly, the securities are suitable 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 suitability 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 July 15, 2025, which is during the marketing period and prior to the pricing date of these securities.

§ You may lose some or all of your investment. Unlike conventional debt securities, the securities do not provide for the repayment of the stated principal amount at maturity in all circumstances. If the securities are not automatically redeemed prior to maturity, your payment at maturity will depend on the final underlying value of the worst performing underlying on the final valuation date. If the final underlying value of the worst performing underlying on the final valuation date is less than its final buffer value, you will not receive the stated principal amount of your securities at maturity and, instead, will receive underlying shares of the worst performing underlying on the final valuation date (or, in our sole discretion, cash based on its final underlying value) that will be worth less than the stated principal amount and possibly nothing. There is no minimum payment at maturity on the securities, and you may lose up to all of your investment.

We may elect, in our sole discretion, to pay you cash at maturity in lieu of delivering any underlying shares of the worst performing underlying on the final valuation date. If we elect to pay you cash at maturity in lieu of delivering any underlying shares, the amount of that cash may be less than the market value of the underlying shares on the maturity date because the market value will likely fluctuate between the final valuation date and the maturity date. Conversely, if we do not exercise our cash election right and instead deliver underlying shares of the worst performing underlying on the final valuation date to you on the maturity date, the market value of such underlying shares may be less than the cash amount you would have received if we had exercised our cash election right. We will have no obligation to take your interests into account when deciding whether to exercise our cash election right.

§ The initial underlying values, set on the strike date, may be higher than the closing values of the underlyings on the pricing date. If the closing values of the underlyings on the pricing date are less than the initial underlying values set on the strike date, the terms of the securities may be less favorable to you than the terms of an alternative investment that may be available to you that offers a similar payout as the securities but with the initial underlying values set on the pricing date.

§ You will not receive any contingent coupon on the contingent coupon payment date following any valuation date on which the closing value of the worst performing underlying on that valuation date is less than its coupon barrier value. A contingent coupon payment will be made on a contingent coupon payment date if and only if the closing value of the worst performing underlying on the immediately preceding valuation date is greater than or equal to its coupon barrier value. If the closing value of the worst performing underlying on any valuation date is less than its coupon barrier value, you will not receive any contingent coupon payment on the immediately following contingent coupon payment date. You will only receive a contingent coupon payment that has not been paid on a subsequent contingent coupon payment date if and only if the closing value of the worst performing underlying on the related valuation date is greater than or equal to its coupon barrier value. If the closing value of the worst performing underlying on each valuation date is below its coupon barrier value, you will not receive any contingent coupon payments over the term of the securities.

§ Higher contingent coupon rates are associated with greater risk. The securities offer contingent coupon payments at an annualized rate that, if all are paid, would produce a yield that is generally higher than the yield on our conventional debt securities of the same maturity. This higher potential yield is associated with greater levels of expected risk as of the pricing date for the securities, including the risk that you may not receive a contingent coupon payment on one or more, or any, contingent coupon payment dates and the risk that the value of what you receive at maturity may be significantly less than the stated principal amount of your securities and may be zero. The volatility of, and correlation between, the closing values of the underlyings are important factors affecting these risks. Greater expected volatility of, and lower expected correlation between, the closing values of the underlyings as of the pricing date may result in a higher contingent coupon rate, but would also represent a greater expected likelihood as of the pricing date that the closing value of the worst performing underlying on one or more valuation dates will be less than its coupon barrier value, such that you will not receive one or more, or any, contingent coupon payments during the term of the securities and that the final underlying value of the worst performing underlying on the final valuation date will be less than its final buffer value, such that you will not be repaid the stated principal amount of your securities at maturity.

§ The securities are subject to heightened risk because they have multiple underlyings. The securities are more risky than similar investments that may be available with only one underlying. With multiple underlyings, there is a greater chance that any one underlying will perform poorly, adversely affecting your return on the securities.

§ The securities are subject to the risks of each of the underlyings and will be negatively affected if any one underlying performs poorly. You are subject to risks associated with each of the underlyings. If any one underlying performs poorly, you will be negatively affected. The securities are not linked to a basket composed of the underlyings, where the blended performance of the underlyings would

PS-6

Citigroup Global Markets Holdings Inc.

be better than the performance of the worst performing underlying alone. Instead, you are subject to the full risks of whichever of the underlyings is the worst performing underlying.

§ You will not benefit in any way from the performance of any better performing underlying. The return on the securities depends solely on the performance of the worst performing underlying, and you will not benefit in any way from the performance of any better performing underlying.

§ You will be subject to risks relating to the relationship between the underlyings. It is preferable from your perspective for the underlyings to be correlated with each other, in the sense that their closing values tend to increase or decrease at similar times and by similar magnitudes. By investing in the securities, you assume the risk that the underlyings will not exhibit this relationship. The less correlated the underlyings, the more likely it is that any one of the underlyings will perform poorly over the term of the securities. All that is necessary for the securities to perform poorly is for one of the underlyings to perform poorly. It is impossible to predict what the relationship between the underlyings will be over the term of the securities. The underlyings differ in significant ways and, therefore, may not be correlated with each other.

§ You may not be adequately compensated for assuming the downside risk of the worst performing underlying. The potential contingent coupon payments on the securities are the compensation you receive for assuming the downside risk of the worst performing underlying, as well as all the other risks of the securities. That compensation is effectively “at risk” and may, therefore, be less than you currently anticipate. First, the actual yield you realize on the securities could be lower than you anticipate because the coupon is “contingent” and you may not receive a contingent coupon payment on one or more, or any, of the contingent coupon payment dates. Second, the contingent coupon payments are the compensation you receive not only for the downside risk of the worst performing underlying, but also for all of the other risks of the securities, including the risk that the securities may be automatically redeemed prior to maturity, interest rate risk and our and Citigroup Inc.’s credit risk. If those other risks increase or are otherwise greater than you currently anticipate, the contingent coupon payments may turn out to be inadequate to compensate you for all the risks of the securities, including the downside risk of the worst performing underlying.

§ The securities may be automatically redeemed prior to maturity, limiting your opportunity to receive contingent coupon payments. On any potential autocall date, the securities will be automatically called for redemption if the closing value of the worst performing underlying on that potential autocall date is greater than or equal to its initial underlying value. As a result, if the worst performing underlying performs in a way that would otherwise be favorable, the securities are likely to be automatically redeemed, cutting short your opportunity to receive contingent coupon payments. If the securities are automatically redeemed prior to maturity, you may not be able to reinvest your funds in another investment that provides a similar yield with a similar level of risk.

§ The securities offer downside exposure to the worst performing underlying, but no upside exposure to any underlying. You will not participate in any appreciation in the value of any underlying over the term of the securities. Consequently, your return on the securities will be limited to the contingent coupon payments you receive, if any, and may be significantly less than the return on any underlying over the term of the securities. In addition, as an investor in the securities, you will not receive any dividends or other distributions or have any other rights with respect to any of the underlyings.

§ The performance of the securities will depend on the closing values of the underlyings solely on the valuation dates, which makes the securities particularly sensitive to volatility in the closing values of the underlyings on or near the valuation dates. Whether the contingent coupon will be paid on any given contingent coupon payment date (and whether any previously unpaid contingent coupon payments will be paid) and whether the securities will be automatically redeemed prior to maturity will depend on the closing values of the underlyings solely on the applicable valuation dates, regardless of the closing values of the underlyings on other days during the term of the securities. If the securities are not automatically redeemed prior to maturity, what you receive at maturity will depend solely on the closing value of the worst performing underlying on the final valuation date, and not on any other day during the term of the securities. Because the performance of the securities depends on the closing values of the underlyings on a limited number of dates, the securities will be particularly sensitive to volatility in the closing values of the underlyings on or near the valuation dates. You should understand that the closing value of each underlying has historically been highly volatile.

§ 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 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, is 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) any selling concessions or other 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

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Citigroup Global Markets Holdings Inc.

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, and correlation between, the closing values of the underlyings, dividend yields on the underlyings 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 is payable on the securities.

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 closing values of the underlyings, the volatility of, and correlation between, the closing values of the underlyings, dividend yields on the underlyings, interest rates generally, the time remaining to maturity and our and Citigroup Inc.’s creditworthiness, as reflected in our secondary market rate, among other factors described under “Risk Factors Relating to the Securities—Risk Factors Relating to All Securities—The value of your securities prior to maturity will fluctuate based on many unpredictable factors” in the accompanying product supplement. Changes in the closing values of the underlyings 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 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.

§ Our offering of the securities is not a recommendation of any underlying. The fact that we are offering the securities does not mean that we believe that investing in an instrument linked to the underlyings 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 underlyings or in instruments related to the underlyings, and may publish research or express opinions, that in each case are inconsistent with an investment linked to the underlyings. These and other activities of our affiliates may affect the closing values of the underlyings in a way that negatively affects the value of and your return on the securities.

§ The closing value of an underlying 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 in the underlyings or in financial instruments related to the underlyings and may adjust such positions during the term of the securities. Our affiliates also take positions in the underlyings or in financial instruments related to the underlyings 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 closing values of the underlyings in a way that negatively affects the value of and your return on 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 engage in business activities with a wide range of companies. These activities include extending loans, making and facilitating investments, underwriting securities offerings and providing advisory services. These activities could involve or affect the underlyings in a way that negatively affects the value of and your return on the securities. They could also result in substantial returns for us or our

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Citigroup Global Markets Holdings Inc.

affiliates while the value of the securities declines. In addition, in the course of this business, we or our affiliates may acquire non-public information, which will not be disclosed to you.

§ 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 an underlying, 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. See “Risk Factors Relating to the Securities—Risk Factors Relating to All Securities—The calculation agent, which is an affiliate of ours, will make important determinations with respect to the securities” in the accompanying product supplement.

§ Even if an underlying 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 by an underlying unless the amount of the dividend per share, together with any other dividends paid in the same quarter, exceeds the dividend paid per share in the most recent quarter by an amount equal to at least 10% of the closing value of that underlying on the date of declaration of the dividend. Any dividend will reduce the closing value of the underlying by the amount of the dividend per share. If an underlying pays any dividend for which an adjustment is not made under the terms of the securities, holders of the securities will 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 may have a dilutive effect on or otherwise adversely affect the closing value of an underlying. For example, we will not make any adjustment for ordinary dividends or extraordinary dividends that do not meet the criteria described above, partial tender offers or additional underlying share issuances. 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 of an underlying would not.

§ The securities may become linked to an underlying other than an original underlying upon the occurrence of a reorganization event or upon the delisting of the underlying shares of that original underlying. For example, if an underlying enters into a merger agreement that provides for holders of its underlying shares to receive shares of another entity and such shares are marketable securities, the closing value of that underlying following consummation of the merger will be based on the value of such other shares. Additionally, if the underlying shares of an underlying are delisted, the calculation agent may select a successor underlying. See “Description of the Securities—Certain Additional Terms for Securities Linked to an Underlying Company or an Underlying ETF” in the accompanying product supplement.

§ If the underlying shares of an underlying are delisted, we may call the securities prior to maturity for an amount that may be less than the stated principal amount. If we exercise this call right, you will receive the amount described under “Description of the Securities—Certain Additional Terms for Securities Linked to an Underlying Company or an Underlying ETF—Delisting of an Underlying Company” in the accompanying product supplement. This amount may be less, and possibly significantly less, than the stated principal amount of the securities.

§ 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 described in “United States Federal Tax Considerations” below.  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.  Moreover, future legislation, Treasury regulations or IRS guidance could adversely affect the U.S. federal tax treatment of the securities, possibly retroactively.

Non-U.S. investors should note that persons having withholding responsibility in respect of the securities may withhold on any coupon payment paid to a non-U.S. investor, generally at a rate of 30%.  To the extent that we have withholding responsibility in respect of the securities, we intend to so withhold.

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.

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Citigroup Global Markets Holdings Inc.

Information About Broadcom Inc.

Broadcom Inc. designs, develops, and supplies semiconductor and infrastructure software solutions. The underlying shares of Broadcom Inc. are registered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Information provided to or filed with the SEC by Broadcom Inc. pursuant to the Exchange Act can be located by reference to the SEC file number 001-38449 through the SEC’s website at http://www.sec.gov. In addition, information regarding Broadcom Inc. may be obtained from other sources including, but not limited to, press releases, newspaper articles and other publicly disseminated documents. The underlying shares of Broadcom Inc. trade on the Nasdaq Global Select Market under the ticker symbol “AVGO.”

We have derived all information regarding Broadcom Inc. from publicly available information and have not independently verified any information regarding Broadcom Inc. This pricing supplement relates only to the securities and not to Broadcom Inc. We make no representation as to the performance of Broadcom Inc. over the term of the securities.

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

Historical Information

The closing value of Broadcom Inc. on July 10, 2025 was $275.40.

The graph below shows the closing value of Broadcom Inc. for each day such value was available from January 2, 2015 to July 10, 2025. We obtained the closing values from Bloomberg L.P., without independent verification. If certain corporate transactions occurred during the historical period shown below, including, but not limited to, spin-offs or mergers, then the closing values shown below for the period prior to the occurrence of any such transaction have been adjusted by Bloomberg L.P. as if any such transaction had occurred prior to the first day in the period shown below. You should not take historical closing values as an indication of future performance.

Broadcom Inc. – Historical Closing Values January 2, 2015 to July 10, 2025

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Citigroup Global Markets Holdings Inc.

Information About Palo Alto Networks, Inc.

Palo Alto Networks, Inc. offers firewalls that identify and control applications, scan content to stop threats and prevent data leakage. The underlying shares of Palo Alto Networks, Inc. are registered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Information provided to or filed with the SEC by Palo Alto Networks, Inc. pursuant to the Exchange Act can be located by reference to the SEC file number 001-35594 through the SEC’s website at http://www.sec.gov. In addition, information regarding Palo Alto Networks, Inc. may be obtained from other sources including, but not limited to, press releases, newspaper articles and other publicly disseminated documents. The underlying shares of Palo Alto Networks, Inc. trade on the Nasdaq Global Select Market under the ticker symbol “PANW.”

We have derived all information regarding Palo Alto Networks, Inc. from publicly available information and have not independently verified any information regarding Palo Alto Networks, Inc. This pricing supplement relates only to the securities and not to Palo Alto Networks, Inc. We make no representation as to the performance of Palo Alto Networks, Inc. over the term of the securities.

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

Historical Information

The closing value of Palo Alto Networks, Inc. on July 10, 2025 was $192.07.

The graph below shows the closing value of Palo Alto Networks, Inc. for each day such value was available from October 25, 2021 to July 10, 2025. We obtained the closing values from Bloomberg L.P., without independent verification. If certain corporate transactions occurred during the historical period shown below, including, but not limited to, spin-offs or mergers, then the closing values shown below for the period prior to the occurrence of any such transaction have been adjusted by Bloomberg L.P. as if any such transaction had occurred prior to the first day in the period shown below. You should not take historical closing values as an indication of future performance.

Palo Alto Networks, Inc. – Historical Closing Values October 25, 2021 to July 10, 2025

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Citigroup Global Markets Holdings Inc.

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.

Due to the lack of any controlling legal authority, there is substantial uncertainty regarding the U.S. federal tax consequences of an investment in the securities.  In connection with any information reporting requirements we may have in respect of the securities under applicable law, we intend (in the absence of an administrative determination or judicial ruling to the contrary) to treat the securities for U.S. federal income tax purposes as prepaid forward contracts with associated coupon payments that will be treated as gross income to you at the time received or accrued in accordance with your regular method of tax accounting.  In the opinion of our counsel, Davis Polk & Wardwell LLP, this treatment of the securities is reasonable under current law; however, our counsel has advised us that it is unable to conclude affirmatively that this treatment is more likely than not to be upheld, and that alternative treatments are possible.  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:

· Any coupon payments on the securities should be taxable as ordinary income to you at the time received or accrued in accordance with your regular method of accounting for U.S. federal income tax purposes.

· Upon a sale or exchange of a security (including retirement at maturity for cash), you should recognize capital gain or loss equal to the difference between the amount realized and your tax basis in the security.  For this purpose, the amount realized does not include any coupon paid on retirement and may not include sale proceeds attributable to an accrued coupon, which may be treated as a coupon payment.  Such gain or loss should be long-term capital gain or loss if you held the security for more than one year.  

· If, upon retirement of the securities, you receive underlying shares, you should not recognize gain or loss with respect to the underlying shares received, other than any fractional underlying share for which you receive cash. Your basis in any underlying shares received, including any fractional underlying share deemed received, should be equal to your tax basis in the securities.  Your holding period for any underlying shares received should start on the day after receipt. With respect to any cash received in lieu of a fractional share, you should recognize capital loss in an amount equal to the difference between the amount of cash received in lieu of the fractional share and the portion of your tax basis in the securities that is allocable to the fractional share.  

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.

This discussion does not address the U.S. federal tax consequences of the ownership or disposition of the underlying shares that you may receive at maturity. You should consult your tax adviser regarding the particular U.S. federal tax consequences of the ownership and disposition of the underlying shares.

Withholding Tax on Non-U.S. Holders. Because significant aspects of the tax treatment of the securities are uncertain, persons having withholding responsibility in respect of the securities may withhold on any coupon payment paid to Non-U.S. Holders (as defined in the accompanying product supplement), generally at a rate of 30%. To the extent that we have (or an affiliate of ours has) withholding responsibility in respect of the securities, we intend to so withhold.  In order to claim an exemption from, or a reduction in, the 30% withholding, you may need to comply with certification requirements to establish that you are not a U.S. person and are eligible for such an exemption or reduction under an applicable tax treaty. You should consult your tax adviser regarding the tax treatment of the securities, including the possibility of obtaining a refund of any amounts withheld and the certification requirement described above.

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, 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 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.

We will not be required to pay any additional amounts with respect to amounts withheld.

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Citigroup Global Markets Holdings Inc.

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.

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 $12.50 for each security sold in this offering. From this underwriting fee, CGMI will pay selected dealers not affiliated with CGMI a fixed selling concession of $12.50 for each security they sell. For the avoidance of doubt, any fees or selling concessions described in this pricing supplement will not be rebated if the securities are automatically redeemed prior to maturity.

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 certain terms of the securities have not yet been fixed and 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.”

Contact

Clients may contact their local brokerage representative. Third-party distributors may contact Citi Structured Investment Sales at (212) 723-7005.

© 2025 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.

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FAQ

What coupon does the Citigroup (C) autocallable note pay?

It offers a contingent coupon of at least 10.25% per annum, paid quarterly at ≥2.5625% of principal, but only if the worst-performing share closes ≥59% of its initial value on the relevant valuation date.

How much principal protection is provided by the note?

There is a 41% buffer; if the worst-performing share stays at or above 59% of its initial level on the final valuation date, investors receive full $1,000. Below that, principal converts to shares and losses mirror the stock’s decline.

When can the securities be called early?

On any of the five quarterly valuation dates from 16 Oct 2025 to 16 Oct 2026, if the worst-performing share is at or above its initial level, the note is automatically redeemed for $1,000 plus the due coupon.

What is the estimated value versus the issue price?

Citigroup expects an estimated value of at least $928.50 per $1,000 note on the pricing date, reflecting structuring and hedging costs; the issue price is $1,000.

Are the notes listed on an exchange?

No. They will not be listed; secondary liquidity relies solely on Citigroup Global Markets Inc. making a market at its discretion.

What underlying stocks determine performance?

Broadcom Inc. (AVGO) and Palo Alto Networks Inc. (PANW); the note’s payments are based on the worst performer of the two.

What are the main risks investors should consider?

Principal loss if the buffer is broken, missed coupons when barriers are not met, credit risk of Citi, illiquidity, and complex tax treatment including possible withholding for non-U.S. holders.