SCHEDULE 13D/A 0001539497-25-002707 0000921669 XXXXXXXX LIVE 14 Common Stock, Par Value $1.00 per share 11/26/2025 false 0001692115 844895102 Southwest Gas Holdings, Inc.

C/O SOUTHWEST GAS CORPORATION 8360 S. DURANGO DRIVE LAS VEGAS NV 89113

Jesse A. Lynn COO (305) 422-4100 Icahn Capital LP 16690 Collins Avenue, PH-1 Sunny Isles Beach FL 33160 0001322827 N Icahn Partners Master Fund LP WC N DE 2613437.00 2613437.00 2613437.00 2613437.00 2613437.00 N 3.62 PN 0001322825 N Icahn Offshore LP OO N DE 0.00 2613437.00 0.00 2613437.00 2613437.00 N 3.62 PN 0001313666 N Icahn Partners LP WC N DE 3419167.00 3419167.00 3419167.00 3419167.00 3419167.00 N 4.74 PN 0001322826 N Icahn Onshore LP OO N DE 0.00 3419167.00 0.00 3419167.00 3419167.00 N 4.74 PN 0001412093 N Icahn Capital LP OO N DE 0.00 6032604.00 0.00 6032604.00 6032604.00 N 8.36 PN 0001412091 N IPH GP LLC OO N DE 0.00 6032604.00 0.00 6032604.00 6032604.00 N 8.36 OO 0001034563 N Icahn Enterprises Holdings L.P. OO N DE 0.00 6032604.00 0.00 6032604.00 6032604.00 N 8.36 PN 0001257324 N Icahn Enterprises G.P. Inc. OO N DE 0.00 6032604.00 0.00 6032604.00 6032604.00 N 8.36 CO 0001080113 N Beckton Corp. OO N DE 0.00 6032604.00 0.00 6032604.00 6032604.00 N 8.36 CO 0001889149 N IEP Utility Holdings LLC OO N DE 0.00 0.00 0.00 0.00 0.00 N 0 OO 0000921669 N Carl C. Icahn OO N X1 0.00 6032604.00 0.00 6032604.00 6032604.00 N 8.36 IN Common Stock, Par Value $1.00 per share Southwest Gas Holdings, Inc. C/O SOUTHWEST GAS CORPORATION 8360 S. DURANGO DRIVE LAS VEGAS NV 89113 This statement constitutes Amendment No. 14 to the Schedule 13D (as amended, the "Schedule 13D") relating to the shares of the common stock, par value $1.00 per share (the "Common Stock"), of Southwest Gas Holdings, Inc., a Delaware corporation (the "Issuer"), and hereby amends the Schedule 13D originally filed with the Securities and Exchange Commission (the "SEC") on June 3, 2022. All capitalized terms contained herein but not otherwise defined shall have the meanings ascribed to such terms in the Schedule 13D. The percentages set forth on the cover pages hereto are based on 72,182,840 shares of Common Stock outstanding as of October 31, 2025, as disclosed by the Issuer in its Form 10-Q for the quarterly period ended September 30, 2025. Item 4 of the Schedule 13D is hereby amended by adding the following: In connection with the execution of the Amended and Restated Cooperation Agreement, dated as of October 14, 2025 (referred to as the "2025 Agreement"), the Issuer and the Reporting Persons had previously agreed to enter into a customary form of registration rights agreement with respect to the shares of Common Stock beneficially owned by the Reporting Persons. On November 26, 2025, the Issuer and the Reporting Persons entered into a Registration Rights Agreement (the "Registration Rights Agreement"), pursuant to which the Issuer granted certain customary shelf, underwritten offering and piggy-back registration rights to the Reporting Persons subject to the terms and conditions set forth therein. The Registration Rights Agreement supersedes the registration rights described in Exhibit B of the 2025 Agreement. The foregoing description of the Registration Rights Agreement is qualified in its entirety by reference to the Registration Rights Agreement, a copy of which is included hereto as Exhibit 8. The information set forth in Item 4 of this Schedule 13D is hereby incorporated by reference into this Item 6. Item 7 of the Schedule 13D is hereby amended by the addition of the following exhibit: Exhibit 8. Registration Rights Agreement, dated November 26, 2025, by and among Southwest Gas Holdings, Inc. and the Reporting Persons (incorporated by reference to Exhibit 10.1 to Southwest Gas Holdings, Inc.'s Current Report on Form 8-K filed by with the Securities and Exchange Commission on November 26, 2025). Icahn Partners Master Fund LP /s/ Jesse Lynn 11/26/2025 Icahn Offshore LP /s/ Jesse Lynn 11/26/2025 Icahn Partners LP /s/ Jesse Lynn 11/26/2025 Icahn Onshore LP /s/ Jesse Lynn 11/26/2025 Icahn Capital LP /s/ Jesse Lynn 11/26/2025 IPH GP LLC /s/ Ted Papapostolou 11/26/2025 Icahn Enterprises Holdings L.P. /s/ Ted Papapostolou 11/26/2025 Icahn Enterprises G.P. Inc. /s/ Ted Papapostolou 11/26/2025 Beckton Corp. /s/ Ted Papapostolou 11/26/2025 IEP Utility Holdings LLC /s/ Ted Papapostolou 11/26/2025 Carl C. Icahn /s/ Carl C. Icahn 11/26/2025