SWX / Southwest Gas Holdings, Inc. - Pemfailan SEC, Laporan Tahunan, Penyata Proksi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) September 3, 2025 SOUTHWEST GAS HO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) September 3, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 11, 2025 SOUTHWEST GAS HO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 11, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

SOUTHWEST GAS HOLDINGS, INC. UNAUDITED PRO FORMA CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

EX-99.1 Exhibit 99.1 SOUTHWEST GAS HOLDINGS, INC. UNAUDITED PRO FORMA CONDENSED CONSOLIDATED FINANCIAL STATEMENTS On April 22, 2024, Centuri Holdings, Inc. (“Centuri”), completed its initial public offering (the “Centuri IPO”), prior to which Centuri was a wholly owned subsidiary of the Southwest Gas Holdings, Inc. (“Southwest Gas Holdings” or the “Company”). Immediately upon the completion of the

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 6, 2025 SOUTHWEST GAS HOLDI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 6, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organi

COMMON STOCK PURCHASE AGREEMENT August 6, 2025

EX-10.2 Exhibit 10.2 Certain information has been excluded from this agreement (indicated by “[***]”) because Southwest Gas Holdings, Inc. has determined that such information (i) is not material and (ii) constitutes personal information. COMMON STOCK PURCHASE AGREEMENT August 6, 2025 TABLE OF CONTENTS 1. Purchase and Sale of Stock. 1 1.1 Sale of Centuri Common Stock 1 1.2 Closing 1 2. Representat

Centuri Holdings, Inc. 15,000,000 Shares of Common Stock Underwriting Agreement

EX-10.1 Exhibit 10.1 Centuri Holdings, Inc. 15,000,000 Shares of Common Stock Underwriting Agreement August 7, 2025 J.P. Morgan Securities LLC As Representative of the several Underwriters listed in Schedule 1 hereto c/o J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 Ladies and Gentlemen: Southwest Gas Holdings, Inc., a stockholder (the “Selling Stockholder”) of Centuri Hol

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 6, 2025 SOUTHWEST GAS HOLDI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 6, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organi

Section 906 Certifications–Southwest Gas Holdings, Inc.

Exhibit 32.01 SOUTHWEST GAS HOLDINGS, INC. CERTIFICATION In connection with the periodic report of Southwest Gas Holdings, Inc. (the “Company”) on Form 10-Q for the period ended June 30, 2025 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the President and Chief Executive Officer of the Company, hereby certify as of the date hereof, solely for purposes of

Section 302 Certifications–Southwest Gas Holdings, Inc.

Exhibit 31.01 Certification of Southwest Gas Holdings, Inc. I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Holdings, Inc.; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such stateme

Southwest Gas Holdings, Inc. Reports Second Quarter 2025 Financial Results, Reaffirms Guidance Regulatory Progress and Cost Management Improve Trailing 12-Month Utility ROE to 8.3% Nevada Enacts Law Enabling Alternative Ratemaking for Natural Gas Uti

Release Date: August 6, 2025 Southwest Gas Holdings, Inc. Reports Second Quarter 2025 Financial Results, Reaffirms Guidance Regulatory Progress and Cost Management Improve Trailing 12-Month Utility ROE to 8.3% Nevada Enacts Law Enabling Alternative Ratemaking for Natural Gas Utilities CTRI Follow-on Offerings Drive Over $470 million in Debt Reduction, Strengthening Balance Sheet LAS VEGAS – August

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 ☐ TRANSITION REPORT PURSUANT TO S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number Exact name of registrant as specified in its charter and principal

Section 302 Certifications–Southwest Gas Corporation

Exhibit 31.02 Certification of Southwest Gas Corporation I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements we

Section 906 Certifications–Southwest Gas Corporation

Exhibit 32.02 SOUTHWEST GAS CORPORATION CERTIFICATION In connection with the periodic report of Southwest Gas Corporation on Form 10-Q for the period ended June 30, 2025 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the Chief Executive Officer of Southwest Gas Corporation, hereby certify as of the date hereof, solely for purposes of Title 18, Chapter 63,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) July 2, 2025 Commission File Numbe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) July 2, 2025 Commission File Number Exact name of registrant as specified in its charter and principal office address and telephone number State of Incorporation I.R.S. Employer Identi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) July 8, 2025 SOUTHWEST GAS HOLDING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) July 8, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organiza

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) June 27, 2025 Commission File Numb

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) June 27, 2025 Commission File Number Exact name of registrant as specified in its charter and principal office address and telephone number State of Incorporation I.R.S. Employer Ident

Entry into a Material Definitive Agreement

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) June 27, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organiz

Second Amended and Restated Term Loan Credit Agreement, dated as of June 27, 2025, by and among Southwest Gas Holdings, Inc., the lenders party thereto, JPMorgan Chase Bank, N.A., as Administrative Agent, JPMorgan Chase Bank, N.A., BofA Securities, Inc., Wells Fargo Securities, LLC and U.S. Bank National Association as Joint Lead Arrangers and Joint Bookrunners, Bank of America, N.A. as Syndication Agent, and Wells Fargo Bank, N.A. and U.S. Bank National Association as Co-Documentation Agents.

Exhibit 10.1 Certain information has been excluded from this agreement (indicated by “[***]”) because Southwest Gas Holdings, Inc. has determined that such information (i) is not material and (ii) constitutes personal information. SECOND AMENDED AND RESTATED TERM LOAN CREDIT AGREEMENT dated as of June 27, 2025 among SOUTHWEST GAS HOLDINGS, INC., as Borrower, THE LENDERS LISTED ON THE SIGNATURE PAG

First Amendment to Credit Agreement, dated as of June 27, 2025, to the Revolving Credit Agreement, dated as of August 1, 2024, by and among Southwest Gas Corporation, the lenders party thereto, and Bank of America, N.A., as Administrative Agent and Swingline Lender.

Exhibit 10.1 Certain information has been excluded from this agreement (indicated by “[***]”) because Southwest Gas Corporation has determined that such information (i) is not material and (ii) constitutes personal information. FIRST AMENDMENT TO CREDIT AGREEMENT THIS FIRST AMENDMENT TO CREDIT AGREEMENT (this “Agreement”), dated as of June 27, 2025 (the “First Amendment Effective Date”), is entere

Revolving Credit Agreement, dated as of June 27, 2025, by and among Southwest Gas Holdings, Inc., the lenders party thereto, JPMorgan Chase Bank, N.A. as Administrative Agent and Swingline Lender, Bank of America, N.A. and Wells Fargo Bank, National Association as Co-Syndication Agents, U.S. Bank National Association, MUFG Bank, Ltd., The Toronto-Dominion Bank, New York Branch, Keybank National Association and Mizuho Bank, Ltd. as Co-Documentation Agents, and JPMorgan Chase Bank, N.A., BofA Securities, Inc. and Wells Fargo Securities, LLC as Joint Lead Arrangers and Joint Bookrunners.

Exhibit 10.2 Certain information has been excluded from this agreement (indicated by “[***]”) because Southwest Gas Holdings, Inc. has determined that such information (i) is not material and (ii) constitutes personal information. REVOLVING CREDIT AGREEMENT dated as of June 27, 2025 among SOUTHWEST GAS HOLDINGS, INC., as the Borrower, THE LENDERS LISTED ON THE SIGNATURE PAGES HERETO and JPMORGAN C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 11-K ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 Commission file number 001-37976

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 11-K ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 Commission file number 001-37976 A. Full title of the plan and the address of the plan, if different from that of the issuer named below: SOUTHWEST GAS CORPORATION EMPLOYEES’ INVESTMENT PLAN B. N

Common Stock Purchase Agreement, dated as of June 13, 2025, by and among Southwest Gas Holdings, Inc., Icahn Partners LP and Icahn Partners Master Fund LP.

Exhibit 10.2 COMMON STOCK PURCHASE AGREEMENT June 13, 2025 TABLE OF CONTENTS 1.   Purchase and Sale of Stock 1 1.1  Sale of Centuri Common Stock 1 1.2  Closing 1 2.   Representations, Warranties and Covenants of the Company 2 2.1  Organization, Good Standing and Qualification 2 2.2  Authorization 2 2.3  Title to Shares 2 2.4  Compliance with Other Instruments 2 2.5  No Other Agreements 2 2.6  Brok

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) June 13, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organiz

Underwriting Agreement, dated as of June 16, 2025, by and among Centuri Holdings Inc., Southwest Gas Holdings, Inc. and J.P. Morgan Securities LLC, as representative of the underwriters named therein.

Exhibit 10.1 Centuri Holdings, Inc. 9,750,000 Shares of Common Stock Underwriting Agreement June 16, 2025 J.P. Morgan Securities LLC As Representative of the several Underwriters listed in Schedule 1 hereto c/o J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 Ladies and Gentlemen: Southwest Gas Holdings, Inc., a stockholder (the “Selling Stockholder”) of Centuri Holdings, Inc

Great Basin Expansion Project Shows Strong Interest for Natural Gas Expansion in Northern Nevada Southwest Gas announces that indicative capacity requests show high demand for natural gas as Great Basin Gas Transmission Company 2028 Expansion Project

For Immediate Release June 5, 2025 Great Basin Expansion Project Shows Strong Interest for Natural Gas Expansion in Northern Nevada Southwest Gas announces that indicative capacity requests show high demand for natural gas as Great Basin Gas Transmission Company 2028 Expansion Project Binding Open Season closes.

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) June 5, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organiza

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 29, 2025 Commission File Number Exact name of registrant as specified in its charter and principal office address and telephone number State of Incorporation I.R.S. Employer Identi

Termination of a Material Definitive Agreement

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 19, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organiza

Common Stock Purchase Agreement, dated as of May 19, 2025, by and among Southwest Gas Holdings, Inc., Icahn Partners LP and Icahn Partners Master Fund LP

Exhibit 10.2 COMMON STOCK PURCHASE AGREEMENT May 19, 2025 TABLE OF CONTENTS 1. Purchase and Sale of Stock 1 1.1 Sale of Centuri Common Stock 1 1.2 Closing 1 2. Representations, Warranties and Covenants of the Company 2 2.1 Organization, Good Standing and Qualification 2 2.2 Authorization 2 2.3 Title to Shares 2 2.4 Compliance with Other Instruments 2 2.5 No Other Agreements 2 2.6 Brokers or Finder

Underwriting Agreement, dated as of May 20, 2025, by and among Centuri Holdings Inc., Southwest Gas Holdings, Inc. and J.P. Morgan Securities LLC, as representative of the underwriters named therein.*

Exhibit 10.1 Centuri Holdings, Inc. 9,000,000 Shares of Common Stock Underwriting Agreement May 20, 2025 J.P. Morgan Securities LLC As Representative of the several Underwriters listed in Schedule 1 hereto c/o J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 Ladies and Gentlemen: Southwest Gas Holdings, Inc., a stockholder (the “Selling Stockholder”) of Centuri Holdings, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13

15-12G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File Number 001-37976 Southwest Gas Holdings, Inc. (Exact name of registrant as s

EX-99.25

NOTIFICATION OF THE REMOVAL FROM LISTING AND REGISTRATION OF THE STATED SECURITIES The New York Stock Exchange hereby notifies the SEC of its intention to remove the entire class of the stated securities from listing and registration on the Exchange at the opening of business on June 02, 2025, pursuant to the provisions of Rule 12d2-2 (a).

Section 906 Certifications–Southwest Gas Corporation

Exhibit 32.02 SOUTHWEST GAS CORPORATION CERTIFICATION In connection with the periodic report of Southwest Gas Corporation on Form 10-Q for the period ended March 31, 2025 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the Chief Executive Officer of Southwest Gas Corporation, hereby certify as of the date hereof, solely for purposes of Title 18, Chapter 63,

Section 302 Certifications–Southwest Gas Corporation

Exhibit 31.02 Certification of Southwest Gas Corporation I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements we

Section 906 Certifications–Southwest Gas Holdings, Inc.

Exhibit 32.01 SOUTHWEST GAS HOLDINGS, INC. CERTIFICATION In connection with the periodic report of Southwest Gas Holdings, Inc. (the “Company”) on Form 10-Q for the period ended March 31, 2025 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the President and Chief Executive Officer of the Company, hereby certify as of the date hereof, solely for purposes of

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 12, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organiza

Section 302 Certifications–Southwest Gas Holdings, Inc.

Exhibit 31.01 Certification of Southwest Gas Holdings, Inc. I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Holdings, Inc.; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such stateme

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 ☐ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number Exact name of registrant as specified in its charter and principa

Southwest Gas Holdings, Inc. Reports First Quarter 2025 Financial Results, Reaffirms Guidance Delivers a Last-Twelve-Months’ Utility ROE of 8.2% and Earnings Growth of 5.2% over 1Q 2024 Receives ~$80.2 Million Annual Revenue Increase from Completed A

Release Date May 12, 2025 Southwest Gas Holdings, Inc. Reports First Quarter 2025 Financial Results, Reaffirms Guidance Delivers a Last-Twelve-Months’ Utility ROE of 8.2% and Earnings Growth of 5.2% over 1Q 2024 Receives ~$80.2 Million Annual Revenue Increase from Completed Arizona Rate Case LAS VEGAS – May 12, 2025 – Southwest Gas Holdings, Inc. (NYSE: SWX) (“Southwest Gas Holdings” or “Company”)

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 1, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organizat

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) o Definitive Proxy Statement x Definitive Additional Materials o Soliciting Material Under Rule 14a-12 Southwest Gas Holdings, Inc.

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) x Definitive Proxy Statement o Definitive Additional Materials o Soliciting Material Under Rule 14a-12 Southwest Gas Holdings, Inc.

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) March 9, 2025 Commission File Number Exact name of registrant as specified in its charter and principal office address and telephone number State of Incorporation I.R.S. Employer Ident

Consent of PricewaterhouseCoopers LLP, an independent registered public accounting firm - Southwest Gas Corporation.

Exhibit 23.02 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We hereby consent to the incorporation by reference in the Registration Statement on Form S-3 (No. 333-275774-01) of Southwest Gas Corporation of our report dated February 26, 2025 relating to the financial statements, which appears in this Form 10-K. /s/ PricewaterhouseCoopers LLP Las Vegas, Nevada February 26, 2025

Section 302 Certifications–Southwest Gas Corporation.

Exhibit 31.02 Certification of Southwest Gas Corporation I, Karen S. Haller, certify that: 1. I have reviewed this annual report on Form 10-K of Southwest Gas Corporation; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements wer

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal period ended December 31, 2024 ☐ TRANSITION REPORT PURSUANT TO SEC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal period ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number Exact name of registrant as specified in its charter and principal o

Agreement under the Southwest Gas Holdings

PERFORMANCE STOCK UNIT AWARD AGREEMENT UNDER THE SOUTHWEST GAS HOLDINGS, INC. 2024 OMNIBUS INCENTIVE PLAN This Performance Stock Unit Award Agreement (this “Award Agreement”) is dated as of [●], 2025, by and between Southwest Gas Holdings, Inc., a Delaware corporation (the “Company”), and [●] (the “Participant”), pursuant to the Southwest Gas Holdings, Inc. 2024 Omnibus Incentive Plan (the “Plan”)

Section 906 Certifications–Southwest Gas Corporation.

Exhibit 32.02 SOUTHWEST GAS CORPORATION CERTIFICATION In connection with the periodic report of Southwest Gas Corporation on Form 10-K for the period ended December 31, 2024 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the Chief Executive Officer of Southwest Gas Corporation, hereby certify as of the date hereof, solely for purposes of Title 18, Chapter

Section 906 Certifications–Southwest Gas Holdings, Inc.

Exhibit 32.01 SOUTHWEST GAS HOLDINGS, INC. CERTIFICATION In connection with the periodic report of Southwest Gas Holdings, Inc. (the “Company”) on Form 10-K for the period ended December 31, 2024 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the President and Chief Executive Officer of the Company, hereby certify as of the date hereof, solely for purposes

Southwest Gas Holdings, Inc. Reports Fourth Quarter and Full-Year 2024 Financial Results Delivers 8.1% Utility ROE and Earnings Growth of ~8.0% Year-over-Year O&M/Customer Flat Year-over-Year Reflecting Progress on Utility Cost Optimization Initiated

For Immediate Release February 26, 2025 Southwest Gas Holdings, Inc. Reports Fourth Quarter and Full-Year 2024 Financial Results Delivers 8.1% Utility ROE and Earnings Growth of ~8.0% Year-over-Year O&M/Customer Flat Year-over-Year Reflecting Progress on Utility Cost Optimization Initiated 2025 Utility Net Income and Capital Expenditures Guidance and Forward-Looking Utility Net Income CAGR and Rat

Amendment No. 5 to Second Amended and Restated Credit Agreement, dated as of May 13, 2024, among Centuri Group, Inc., Centuri Canada Division Inc., the lenders party thereto, Wells Fargo Bank, National Association, as administrative agent, and the other parties named therein.

Execution Version FIFTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT Dated as of May 13, 2024 This FIFTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT (this “Amendment”) is by and among CENTURI GROUP, INC.

Consent of PricewaterhouseCoopers LLP, an independent registered public accounting firm - Southwest Gas Holdings, Inc.

Exhibit 23.01 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We hereby consent to the incorporation by reference in the Registration Statements on Form S-3 (No. 333-275774) and Form S-8 (Nos. 333-215145-01, 333-155581-01, 333-215150-01, 333-185354-01, 333-222048, 333-279320) of Southwest Gas Holdings, Inc. of our report dated February 26, 2025 relating to the financial statements and the

nsider Trading

SOUTHWEST GAS HOLDINGS, INC. INSIDER TRADING POLICY (Approved by the Board of Directors on 05/03/2023) Purpose This Insider Trading Policy (“Policy”) provides guidelines with respect to transactions in the securities of Southwest Gas Holdings, Inc. (“Company”) and the handling of confidential information about the Company, its subsidiaries and the companies with which the Company, or its subsidiar

between Southwest Gas Holdings

UNUTILIZED TAX ASSETS SETTLEMENT AGREEMENT THIS UNUTILIZED INCOME TAX ASSETS SETTLEMENT AGREEMENT (this “Agreement”) is made as of February 24, 2025, by and between Southwest Gas Holdings, Inc.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 26, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

Time-Lapse Restricted Stock Units under the Southwest Gas Holdings

AWARD AGREEMENT FOR TIME-LAPSE RESTRICTED STOCK UNITS UNDER THE SOUTHWEST GAS HOLDINGS, INC.

Performance Share Unit Grant Agreement under the Southwest Gas Holdings, Inc. Omnibus Incentive Plan (EPS/ROE Shares).

PERFORMANCE STOCK UNIT AWARD AGREEMENT UNDER THE SOUTHWEST GAS HOLDINGS, INC. 2024 OMNIBUS INCENTIVE PLAN This Performance Stock Unit Award Agreement (this “Award Agreement”) is dated as of [●], 2025, by and between Southwest Gas Holdings, Inc., a Delaware corporation (the “Company”), and [●] (the “Participant”), pursuant to the Southwest Gas Holdings, Inc. 2024 Omnibus Incentive Plan (the “Plan”)

Section 302 Certifications–Southwest Gas Holdings, Inc.

Exhibit 31.01 Certification of Southwest Gas Holdings, Inc. I, Karen S. Haller, certify that: 1. I have reviewed this annual report on Form 10-K of Southwest Gas Holdings, Inc.; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statemen

ist of subsidiaries - Southwest Gas Holdings, Inc.

EXHIBIT 21.01 SOUTHWEST GAS HOLDINGS, INC. LIST OF SUBSIDIARIES OF THE REGISTRANT AT DECEMBER 31, 2024 SUBSIDIARY NAME STATE OF INCORPORATION OR ORGANIZATION TYPE Southwest Gas Holdings, Inc. Delaware Southwest Gas Utility Group, Inc. California Southwest Gas Corporation California Utility Financial Corp. Nevada The Southwest Companies Nevada Southwest Gas Transmission Company Limited partnership

Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 20, 2025 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

by reference to Exhibit 10.1 to Form 8-K dated February 25, 2025. File No. 001-37976.

PERFORMANCE STOCK UNIT AWARD AGREEMENT UNDER THE SOUTHWEST GAS HOLDINGS, INC. 2024 OMNIBUS INCENTIVE PLAN This Performance Stock Unit Award Agreement (this “Award Agreement”) is dated as of [●], 2025, by and between Southwest Gas Holdings, Inc., a Delaware corporation (the “Company”), and Karen S. Haller (the “Participant”), pursuant to the Southwest Gas Holdings, Inc. 2024 Omnibus Incentive Plan

SWX / Southwest Gas Holdings, Inc. / ICAHN CARL C - FORM SC 13D/A Activist Investment

SC 13D/A 1 n2779x265-sc13da.htm FORM SC 13D/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment 10)* Southwest Gas Holdings, Inc. (Name of Issuer) Common Stock, Par Value $1.00 per share (Title of Class of Securities) 844895102 (CUSIP Number) Jesse A. Lynn Chief Operating Officer Icahn Capital LP 16690 Collins Avenue, PH-1 S

CTRI / Centuri Holdings, Inc. / Southwest Gas Holdings, Inc. - SC 13G Passive Investment

SC 13G 1 d885050dsc13g.htm SC 13G SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b),(c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(b) (Amendment No. )1 Centuri Holdings, Inc. (Name of Issuer) Common Stock, par value $0.01 per share (Title of Class of Securities) 155923105

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) November 6, 2024 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or orga

Section 906 Certifications–Southwest Gas Corporation

Exhibit 32.02 SOUTHWEST GAS CORPORATION CERTIFICATION In connection with the periodic report of Southwest Gas Corporation on Form 10-Q for the period ended September 30, 2024 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the Chief Executive Officer of Southwest Gas Corporation, hereby certify as of the date hereof, solely for purposes of Title 18, Chapter

Section 302 Certifications–Southwest Gas Holdings, Inc.

Exhibit 31.01 Certification of Southwest Gas Holdings, Inc. I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Holdings, Inc.; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such stateme

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 ☐ TRANSITION REPORT PURSUANT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number Exact name of registrant as specified in its charter and prin

Southwest Gas Holdings, Inc. Reports Third Quarter 2024 Financial Results; Expects Utility Net Income Within Top Half of Guidance Range Delivers Strong Utility Earnings with 9% Year-to-Date Earnings Growth Year-over-Year Utility Files California Rate

Release Date November 6, 2024 Southwest Gas Holdings, Inc. Reports Third Quarter 2024 Financial Results; Expects Utility Net Income Within Top Half of Guidance Range Delivers Strong Utility Earnings with 9% Year-to-Date Earnings Growth Year-over-Year Utility Files California Rate Case; Advances Arizona Rate Case Margin Improvement From Nevada Rate Case Outcome LAS VEGAS – November 6, 2024 – Southw

Section 906 Certifications–Southwest Gas Holdings, Inc.

Exhibit 32.01 SOUTHWEST GAS HOLDINGS, INC. CERTIFICATION In connection with the periodic report of Southwest Gas Holdings, Inc. (the “Company”) on Form 10-Q for the period ended September 30, 2024 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the President and Chief Executive Officer of the Company, hereby certify as of the date hereof, solely for purpose

Section 302 Certifications–Southwest Gas Corporation

Exhibit 31.02 Certification of Southwest Gas Corporation I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements we

SWX / Southwest Gas Holdings, Inc. / ICAHN CARL C - SC 13D/A Activist Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment 9)* Southwest Gas Holdings, Inc. (Name of Issuer) Common Stock, Par Value $1.00 per share (Title of Class of Securities) 844895102 (CUSIP Number) Jesse A. Lynn Chief Operating Officer Icahn Capital LP 16690 Collins Avenue, PH-1 Sunny Isles Beach, FL 33160 (305) 422-4100 (Name

Amended and Restated Cooperation Agreement, dated as of October 15, 2024, by and among the Icahn Group and Southwest Gas Holdings, Inc. Incorporated herein by reference to Exhibit 10.1 to Form 8-K dated October 15, 2024. File No. 001-37976.

Exhibit 10.1 Certain information has been excluded from this agreement (indicated by “[***]”) because Southwest Gas Holdings, Inc. has determined that such information (i) is not material and (ii) constitutes personal information. Execution Version AMENDED AND RESTATED COOPERATION AGREEMENT This Amended and Restated Cooperation Agreement, dated as of October 15, 2024 (this “Agreement”), is by and

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) October 15, 2024 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or orga

SWX / Southwest Gas Holdings, Inc. / ICAHN CARL C - SC 13D/A Activist Investment

SC 13D/A 1 tm2421713d5sc13da.htm SC 13D/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment 8)* Southwest Gas Holdings, Inc. (Name of Issuer) Common Stock, Par Value $1.00 per share (Title of Class of Securities) 844895102 (CUSIP Number) Jesse A. Lynn Chief Operating Officer Icahn Capital LP 16690 Collins Avenue, PH-1 Sunny

Equity Distribution Agreement, dated August 6, 2024 by and among Southwest Gas Holdings, Inc., J.P. Morgan Securities LLC and Wells Fargo Securities, LLC.

Exhibit 1.1 Certain information has been excluded from this agreement (indicated by “[***]”) because Southwest Gas Holdings, Inc. has determined that such information (i) is not material and (ii) constitutes personal information. EQUITY DISTRIBUTION AGREEMENT This Equity Distribution Agreement (this “Agreement”) is dated August 6, 2024, by and among SOUTHWEST GAS HOLDINGS, INC., a Delaware corpora

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 6, 2024 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organi

Section 906 Certifications–Southwest Gas Holdings, Inc.

Exhibit 32.01 SOUTHWEST GAS HOLDINGS, INC. CERTIFICATION In connection with the periodic report of Southwest Gas Holdings, Inc. (the “Company”) on Form 10-Q for the period ended June 30, 2024 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the President and Chief Executive Officer of the Company, hereby certify as of the date hereof, solely for purposes of

Calculation of Filing Fee Table (Form Type) Southwest Gas Holdings, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities

Exhibit 107 Calculation of Filing Fee Table 424(b)(5) (Form Type) Southwest Gas Holdings, Inc.

Section 302 Certifications–Southwest Gas Corporation

Exhibit 31.02 Certification of Southwest Gas Corporation I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements we

Up to $340,000,000 Common Stock

424B5 Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-275774 PROSPECTUS SUPPLEMENT (To Prospectus dated November 28, 2023) Up to $340,000,000 Common Stock We have entered into an equity distribution agreement with J.P. Morgan Securities LLC (“JPM”) and Wells Fargo Securities, LLC (“Wells Fargo”) relating to shares of our common stock, par value $1.00 per share, offered by t

Section 302 Certifications–Southwest Gas Holdings, Inc.

Exhibit 31.01 Certification of Southwest Gas Holdings, Inc. I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Holdings, Inc.; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such stateme

Southwest Gas Holdings, Inc. Reports Second Quarter 2024 Financial Results; Raises Utility Net Income Guidance Delivers Second Quarter Utility Earnings Growth of 44.5% Margin Improvement From Nevada Rate Case Outcome Centuri IPO Successfully Executed

For Immediate Release August 6, 2024 Southwest Gas Holdings, Inc. Reports Second Quarter 2024 Financial Results; Raises Utility Net Income Guidance Delivers Second Quarter Utility Earnings Growth of 44.5% Margin Improvement From Nevada Rate Case Outcome Centuri IPO Successfully Executed; Net Proceeds Used to Reduce Centuri Debt LAS VEGAS – August 6, 2024 – Southwest Gas Holdings, Inc. (NYSE: SWX)

Section 906 Certifications–Southwest Gas Corporation

Exhibit 32.02 SOUTHWEST GAS CORPORATION CERTIFICATION In connection with the periodic report of Southwest Gas Corporation on Form 10-Q for the period ended June 30, 2024 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the Chief Executive Officer of Southwest Gas Corporation, hereby certify as of the date hereof, solely for purposes of Title 18, Chapter 63,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 ☐ TRANSITION REPORT PURSUANT TO S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number Exact name of registrant as specified in its charter and principal

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 6, 2024 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organi

Amended and Restated Term Loan Credit Agreement, dated as of August 1, 2024, by and among Southwest Gas Holdings, Inc., the lenders party thereto, JPMorgan Chase Bank, N.A., as Administrative Agent, Bank of America, N.A. as Syndication Agent, JPMorgan Chase Bank, N.A., BofA Securities, Inc., Wells Fargo Bank, N.A. and U.S. Bank, National Association as Joint Lead Arrangers and Joint Bookrunners, and Wells Fargo Bank, N.A. and U.S. Bank, National Association as Co-Documentation Agents.

Exhibit 10.1 Certain information has been excluded from this agreement (indicated by “[***]”) because Southwest Gas Holdings, Inc. has determined that such information (i) is not material and (ii) constitutes personal information. AMENDED AND RESTATED TERM LOAN CREDIT AGREEMENT dated as of August 1, 2024 among SOUTHWEST GAS HOLDINGS, INC., as Borrower, THE LENDERS LISTED ON THE SIGNATURE PAGES HER

Revolving Credit Agreement, dated as of August 1, 2024, by and among Southwest Gas Corporation, the lenders party thereto, Bank of America, N.A., as Administrative Agent, JPMorgan Chase Bank, N.A. and Wells Fargo Bank, National Association as Co-Syndication Agents, U.S. Bank National Association, MUFG Bank, Ltd., TD Bank, N.A., Keybank National Association and Mizuho Bank, Ltd. as Co-Documentation Agents, and BofA Securities, Inc., JPMorgan Chase Bank, N.A. and Wells Fargo Securities, LLC as Joint Lead Arrangers and Joint Bookrunners.

Exhibit 10.2 Certain information has been excluded from this agreement (indicated by “[***]”) because Southwest Gas Corporation has determined that such information (i) is not material and (ii) constitutes personal information. Deal CUSIP: 84489QAJ5 Revolver CUSIP: 84489QAK2 REVOLVING CREDIT AGREEMENT dated as of August 1, 2024 among SOUTHWEST GAS CORPORATION, as Borrower, THE LENDERS LISTED ON TH

Entry into a Material Definitive Agreement

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 1, 2024 Commission File Number Exact name of registrant as specified in its charter and principal office address and telephone number State of Incorporation I.R.S. Employer Iden

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 11-K ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 Commission file number 001-37976

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 11-K ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 Commission file number 001-37976 A. Full title of the plan and the address of the plan, if different from that of the issuer named below: SOUTHWEST GAS CORPORATION EMPLOYEES’ INVESTMENT PLAN B. N

NATURAL GAS DISTRIBUTION SEGMENT RATEMAKING JURISDICTIONS AND REGULATORY AGENCIES Southwest Gas Corporation (Southwest Gas) is subject to regulation by the Arizona Corporation Commission (ACC), the Public Utilities Commission of Nevada (PUCN), and th

NATURAL GAS DISTRIBUTION SEGMENT RATEMAKING JURISDICTIONS AND REGULATORY AGENCIES Southwest Gas Corporation (Southwest Gas) is subject to regulation by the Arizona Corporation Commission (ACC), the Public Utilities Commission of Nevada (PUCN), and the California Public Utilities Commission (CPUC).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 14, 2024 SOUTHWEST GAS HOLDING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 14, 2024 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organiza

Southwest Gas Holdings, Inc. 2024 Omnibus Incentive Plan. Incorporated by reference to Exhibit 10.1 to Registration Statement on Form S-8 dated May 10, 2024. File No. 333-279320.

Exhibit 10.1 SOUTHWEST GAS HOLDINGS, INC. 2024 OMNIBUS INCENTIVE PLAN 1. Purposes of the Plan. The purposes of the Plan are to attract and retain the best available personnel, to provide additional incentives to Employees, Directors and Consultants and to promote the success of the Company. 2. Definitions. The following definitions shall apply as used herein and in the individual Award Agreements,

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Table Form S-8 (Form Type) SOUTHWEST GAS HOLDINGS, INC.

As filed with the Securities and Exchange Commission on May 10, 2024

As filed with the Securities and Exchange Commission on May 10, 2024 Registration No.

Section 302 Certifications–Southwest Gas Corporation

Exhibit 31.02 Certification of Southwest Gas Corporation I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements we

Southwest Gas Holdings, Inc. Reports First Quarter 2024 Financial Results, Affirms Guidance Delivers Strong First Quarter Utility Earnings Positive Nevada Rate Case Outcome Centuri IPO Successfully Executed; Net Proceeds Used to Reduce Centuri Debt

For Immediate Release May 8, 2024 Southwest Gas Holdings, Inc. Reports First Quarter 2024 Financial Results, Affirms Guidance Delivers Strong First Quarter Utility Earnings Positive Nevada Rate Case Outcome Centuri IPO Successfully Executed; Net Proceeds Used to Reduce Centuri Debt LAS VEGAS – May 8, 2024 – Southwest Gas Holdings, Inc. (NYSE: SWX) (“Southwest Gas” or “Company”) today reported firs

Section 302 Certifications–Southwest Gas Holdings, Inc.

Exhibit 31.01 Certification of Southwest Gas Holdings, Inc. I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Holdings, Inc.; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such stateme

Section 906 Certifications–Southwest Gas Holdings, Inc.

Exhibit 32.01 SOUTHWEST GAS HOLDINGS, INC. CERTIFICATION In connection with the periodic report of Southwest Gas Holdings, Inc. (the “Company”) on Form 10-Q for the period ended March 31, 2024 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the President and Chief Executive Officer of the Company, hereby certify as of the date hereof, solely for purposes of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 8, 2024 SOUTHWEST GAS HOLDINGS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 8, 2024 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organizat

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 ☐ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number Exact name of registrant as specified in its charter and principa

Section 906 Certifications–Southwest Gas Corporation

Exhibit 32.02 SOUTHWEST GAS CORPORATION CERTIFICATION In connection with the periodic report of Southwest Gas Corporation on Form 10-Q for the period ended March 31, 2024 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the Chief Executive Officer of Southwest Gas Corporation, hereby certify as of the date hereof, solely for purposes of Title 18, Chapter 63,

Performance Stock Unit Award Agreement with Karen S. Haller

Exhibit 10.4 PERFORMANCE STOCK UNIT AWARD AGREEMENT UNDER THE SOUTHWEST GAS HOLDINGS, INC. 2024 OMNIBUS INCENTIVE PLAN This Award Agreement for Performance Stock Units (this “Award Agreement”) is dated as of February 22, 2024, by and between Southwest Gas Holdings, Inc., a Delaware corporation (the “Company”), and Karen S. Haller (the “Participant”), pursuant to the Southwest Gas Holdings, Inc. 20

Performance Stock Unit Award Agreement with Justin L. Brown

Exhibit 10.6 PERFORMANCE STOCK UNIT AWARD AGREEMENT UNDER THE SOUTHWEST GAS HOLDINGS, INC. 2024 OMNIBUS INCENTIVE PLAN This Award Agreement for Performance Stock Units (this “Award Agreement”) is dated as of February 22, 2024, by and between Southwest Gas Holdings, Inc., a Delaware corporation (the “Company”), and Justin L. Brown (the “Participant”), pursuant to the Southwest Gas Holdings, Inc. 20

Form of Performance Stock Unit Award Agreement (EPS and ROE) under the Southwest Gas Holdings, Inc. 2024 Omnibus Incentive Plan

Exhibit 10.2 PERFORMANCE STOCK UNIT AWARD AGREEMENT UNDER THE SOUTHWEST GAS HOLDINGS, INC. 2024 OMNIBUS INCENTIVE PLAN This Performance Stock Unit Award Agreement (this “Award Agreement”) is dated as of [•], 2024, by and between Southwest Gas Holdings, Inc., a Delaware corporation (the “Company”), and [•] (the “Participant”), pursuant to the Southwest Gas Holdings, Inc. 2024 Omnibus Incentive Plan

Form of Restricted Stock Unit Award Agreement under the Southwest Gas Holdings, Inc. 2024 Omnibus Incentive Plan

Exhibit 10.1 AWARD AGREEMENT FOR TIME-LAPSE RESTRICTED STOCK UNITS UNDER THE SOUTHWEST GAS HOLDINGS, INC. 2024 OMNIBUS INCENTIVE PLAN This Award Agreement for Time-Lapse Restricted Stock Units (this “Award Agreement”) is dated as of [•], 2024, by and between Southwest Gas Holdings, Inc., a Delaware corporation (the “Company”), and [•] (the “Participant”), pursuant to the Southwest Gas Holdings, In

Form of Performance Stock Unit Award Agreement (UNI and ROE) under the Southwest Gas Holdings, Inc. 2024 Omnibus Incentive Plan

Exhibit 10.3 PERFORMANCE STOCK UNIT AWARD AGREEMENT UNDER THE SOUTHWEST GAS HOLDINGS, INC. 2024 OMNIBUS INCENTIVE PLAN This Performance Stock Unit Award Agreement (this “Award Agreement”) is dated as of [•], 2024, by and between Southwest Gas Holdings, Inc., a Delaware corporation (the “Company”), and [•] (the “Participant”), pursuant to the Southwest Gas Holdings, Inc. 2024 Omnibus Incentive Plan

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 2, 2024 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organizat

Performance Stock Unit Award Agreement with Robert J. Stefani

Exhibit 10.5 PERFORMANCE STOCK UNIT AWARD AGREEMENT UNDER THE SOUTHWEST GAS HOLDINGS, INC. 2024 OMNIBUS INCENTIVE PLAN This Award Agreement for Performance Stock Units (this “Award Agreement”) is dated as of February 22, 2024, by and between Southwest Gas Holdings, Inc., a Delaware corporation (the “Company”), and Robert J Stefani (the “Participant”), pursuant to the Southwest Gas Holdings, Inc. 2

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 2, 2024 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organizat

Tax Matters Agreement, dated as of April 11, 2024, by and between Southwest Gas Holding, Inc. and Centuri Holdings, Inc. Incorporated herein by reference to Exhibit 10.2 to Form 8-K dated April 11, 2024. File No. 001-37976.

Exhibit 10.2 Execution Version TAX MATTERS AGREEMENT BY AND BETWEEN SOUTHWEST GAS HOLDINGS, INC. AND CENTURI HOLDINGS, INC. DATED AS OF APRIL 11, 2024 TABLE OF CONTENTS Page Article 1 Definition of Terms 2 Article 2 Allocation of Tax Liabilities 9 2.1 Allocation of Tax Liabilities After the Separation Date 9 2.2 Allocation Conventions 9 2.3 Transfer Taxes 10 2.4 Centuri Separate Tax Assets; Tax Re

Registration Rights Agreement, dated as of April 11, 2024, by and between Southwest Gas Holding, Inc. and Centuri Holdings, Inc. Incorporated herein by reference to Exhibit 10.3 to Form 8-K dated April 11, 2024. File No. 001-37976.

Exhibit 10.3 Execution Version REGISTRATION RIGHTS AGREEMENT BY AND BETWEEN CENTURI HOLDINGS, INC., AND SOUTHWEST GAS HOLDINGS, INC. DATED APRIL 11, 2024 TABLE OF CONTENTS ARTICLE I DEFINITIONS Section 1.1 Definitions 1 ARTICLE II DEMAND AND SHELF REGISTRATION Section 2.1 Right to Demand; Demand Notices 4 Section 2.2 Shelf Registration 5 Section 2.3 Deferral or Suspension of Registration 6 Section

Separation Agreement, dated as of April 11, 2024, by and between Southwest Gas Holding, Inc. and Centuri Holdings, Inc. Incorporated herein by reference to Exhibit 10.1 to Form 8-K dated April 11, 2024. File No. 001-37976.

Exhibit 10.1 Execution Version SEPARATION AGREEMENT BY AND BETWEEN SOUTHWEST GAS HOLDINGS, INC. AND CENTURI HOLDINGS, INC. DATED AS OF APRIL 11, 2024 TABLE OF CONTENTS Page ARTICLE I DEFINITIONS 2 ARTICLE II THE SEPARATION 14 2.1 Transfer of Assets and Assumption of Liabilities 14 2.2 Centuri Assets; Southwest Assets 16 2.3 Centuri Liabilities; Southwest Liabilities 18 2.4 Separation Date 20 2.5 A

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) April 11, 2024 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organi

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) March 22, 2024 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organi

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2100 L Street, NW Suite 900 Washington DC 20037 TELEPHONE: 202.887.1500 FACSIMILE: 202.887.0763 WWW.MOFO.COM MORRISON FOERSTER LLP AUSTIN, BEIJING, BERLIN, BOSTON, BRUSSELS, DENVER, HONG KONG, LONDON, LOS ANGELES, MIAMI, NEW YORK, PALO ALTO, SAN DIEGO, SAN FRANCISCO, SHANGHAI, SINGAPORE, TOKYO, WASHINGTON, D.C. March 22, 2024 VIA EDGAR U.S. Securities and Exchange Commission Division of Corporatio

Amendment No.4 to Second Amended and Restated Centuri Credit

Exhibit 10.1 EXECUTION VERSION FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT Dated as of March 22, 2024 This FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT (this “Amendment”) is by and among CENTURI GROUP, INC., a Nevada corporation (the “Company”), and each Additional Borrower that becomes a party thereto in accordance with Section 5.17 thereto, as US Borrower

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. 1)

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) o Definitive Proxy Statement x Definitive Additional Materials o Soliciting Material Under Rule 14a-12 Southwest Gas Holdings, Inc.

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) x Definitive Proxy Statement o Definitive Additional Materials o Soliciting Material Under Rule 14a-12 Southwest Gas Holdings, Inc.

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: x Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) o Definitive Proxy Statement o Definitive Additional Materials o Soliciting Material Under Rule 14a-12 Southwest Gas Holdings, Inc.

Section 302 Certifications–Southwest Gas Holdings, Inc.

Exhibit 31.01 Certification of Southwest Gas Holdings, Inc. I, Karen S. Haller, certify that: 1. I have reviewed this annual report on Form 10-K of Southwest Gas Holdings, Inc.; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statemen

Southwest Gas Holdings, Inc. Reports Fourth Quarter and Full-Year 2023 Financial Results Improved Utility ROE, Strong Centuri Revenue, Net Income, and Adjusted EBITDA Previously Announced Plan to Separate Centuri Remains On Track Initiated 2024 Utili

For Immediate Release February 28, 2024 Southwest Gas Holdings, Inc. Reports Fourth Quarter and Full-Year 2023 Financial Results Improved Utility ROE, Strong Centuri Revenue, Net Income, and Adjusted EBITDA Previously Announced Plan to Separate Centuri Remains On Track Initiated 2024 Utility Earnings and Capital Expenditures Guidance and 2024-2026 Utility Adjusted Net Income CAGR and Rate Base CAG

Consent of PricewaterhouseCoopers LLP, an independent registered public accounting firm - Southwest Gas Corporation.

Exhibit 23.02 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We hereby consent to the incorporation by reference in the Registration Statement on Form S-3 (No. 333-275774-01) of Southwest Gas Corporation of our report dated February 28, 2024 relating to the financial statements, which appears in this Form 10-K. /s/ PricewaterhouseCoopers LLP Las Vegas, Nevada February 28, 2024

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal period ended December 31, 2023 ☐ TRANSITION REPORT PURSUANT TO SEC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal period ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number Exact name of registrant as specified in its charter and principal o

List of subsidiaries - Southwest Gas Holdings, Inc.

EXHIBIT 21.01 SOUTHWEST GAS HOLDINGS, INC. LIST OF SUBSIDIARIES OF THE REGISTRANT AT DECEMBER 31, 2023 SUBSIDIARY NAME STATE OF INCORPORATION OR ORGANIZATION TYPE Southwest Gas Holdings, Inc. Delaware Southwest Gas Utility Group, Inc. California Southwest Gas Corporation California Utility Financial Corp. Nevada The Southwest Companies Nevada Southwest Gas Transmission Company Limited partnership

Southwest Gas Holdings, Inc. Clawback Policy

SOUTHWEST GAS HOLDINGS, INC. CLAWBACK POLICY FOR EXECUTIVE OFFICERS RECEIVING INCENTIVE COMPENSATION (Approved by the Board of Directors on 08/02/2023) Effective Date: October 2, 2023 Introduction In accordance with the applicable rules of The New York Stock Exchange (the “NYSE”) Listed Company Manual (“NYSE Rules”), Section 10D of the Securities Exchange Act of 1934, as amended (the “Exchange Act

Section 906 Certifications–Southwest Gas Corporation.

Exhibit 32.02 SOUTHWEST GAS CORPORATION CERTIFICATION In connection with the periodic report of Southwest Gas Corporation on Form 10-K for the period ended December 31, 2023 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the Chief Executive Officer of Southwest Gas Corporation, hereby certify as of the date hereof, solely for purposes of Title 18, Chapter

Section 302 Certifications–Southwest Gas Corporation.

Exhibit 31.02 Certification of Southwest Gas Corporation I, Karen S. Haller, certify that: 1. I have reviewed this annual report on Form 10-K of Southwest Gas Corporation; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements wer

Section 906 Certifications–Southwest Gas Holdings, Inc.

Exhibit 32.01 SOUTHWEST GAS HOLDINGS, INC. CERTIFICATION In connection with the periodic report of Southwest Gas Holdings, Inc. (the “Company”) on Form 10-K for the period ended December 31, 2023 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the President and Chief Executive Officer of the Company, hereby certify as of the date hereof, solely for purposes

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 28, 2024 SOUTHWEST GAS HO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 28, 2024 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

Consent of PricewaterhouseCoopers LLP, an independent registered public accounting firm - Southwest Gas Holdings, Inc.

Exhibit 23.01 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We hereby consent to the incorporation by reference in the Registration Statements on Form S-3 (No. 333-275774) and Form S-8 (Nos. 333-215145-01, 333-155581-01, 333-215150-01, 333-185354-01, 333-222048) of Southwest Gas Holdings, Inc. of our report dated February 28, 2024 relating to the financial statements and the effectivene

Description of Securities of Southwest Gas Holdings, Inc.

DESCRIPTION OF CAPITAL STOCK General The authorized capital stock of Southwest Gas Holdings, Inc.

SWX / Southwest Gas Holdings, Inc. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv01959-southwestgasholdings.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 9)* Name of issuer: Southwest Gas Holdings Inc Title of Class of Securities: Common Stock CUSIP Number: 844895102 Date of Event Which Requires Filing of this Statement: December 29, 2023 Check the appropriate box

Regulation FD Disclosure, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) December 21, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

Southwest Gas Appoints Accomplished Utility and Energy Industry Executive Bill Fehrman as President and CEO of Centuri Industry Veteran with Decades of Experience Most recently Served as President and Chief Executive Officer of Berkshire Hathaway Ene

Exhibit 99.1 Southwest Gas Appoints Accomplished Utility and Energy Industry Executive Bill Fehrman as President and CEO of Centuri Industry Veteran with Decades of Experience Most recently Served as President and Chief Executive Officer of Berkshire Hathaway Energy LAS VEGAS, December 22, 2023 – Southwest Gas Holdings, Inc. (NYSE: SWX) (“Southwest Gas” or the “Company”) today announced that its B

Transition and Separation Letter, dated as of December 13, 2023, by and between Southwest Gas Holdings, Inc. and Paul M. Daily.

Exhibit 10.1 December 13, 2023 Via Email and UPS Overnight Paul M. Daily RE: Employee Transition and Separation Dear Paul, In light of your forthcoming retirement from Centuri Group, Inc. (the “Company”) and any of its subsidiaries or affiliates, this letter agreement (the “Agreement”) outlines the terms and conditions of your employment as President and Chief Executive Officer (“CEO”) of the Comp

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) December 13, 2023 SOUTHWEST GAS HO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) December 13, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

As filed with the Securities and Exchange Commission on November 28, 2023

Table of Contents As filed with the Securities and Exchange Commission on November 28, 2023 Registration No.

Statement of Eligibility under the Trust Indenture Act of 1939, as amended on Form T-1 of The Bank of New York Mellon Trust Company, N.A. for the form of Indenture of Southwest Gas Holdings, Inc.

Exhibit 25.1 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE ☐ CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO SECTION 305(b)(2) THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. (Exact name of trustee as specified in its charter) 95-

Dividend Reinvestment and Direct Stock Purchase Plan 787,695 Shares of Common Stock, $1 Par Value

Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-275774 PROSPECTUS SUPPLEMENT (To Prospectus dated November 28, 2023) Dividend Reinvestment and Direct Stock Purchase Plan 787,695 Shares of Common Stock, $1 Par Value Southwest Gas Holdings, Inc. is pleased to offer the opportunity to participate in the Dividend Reinvestment and Direct Stock Purchase Plan (the “Plan”) to purch

Calculation of Filing Fee Tables (Form Type) Southwest Gas Holdings, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forwar

Exhibit 107 Calculation of Filing Fee Tables 424(b)(5) (Form Type) Southwest Gas Holdings, Inc.

Powers of Attorney for Southwest Gas Corporation

Exhibit 24.2 POWER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Karen S. Haller and Robert J. Stefani, and each of them (with full power of each to act alone), severally, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and to execute in hi

Powers of Attorney for Southwest Gas Holdings, Inc.

Exhibit 24.1 POWER OF ATTORNEY KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Karen S. Haller and Robert J. Stefani, and each of them (with full power of each to act alone), severally, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for him or her and to execute in hi

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) November 28, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

Statement of Eligibility under the Trust Indenture Act of 1939, as amended on Form T-1 of The Bank of New York Mellon Trust Company, N.A. for the Indenture of Southwest Gas Corporation dated June 4, 2020.

Exhibit 25.2 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE ☐ CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO SECTION 305(b)(2) THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. (Exact name of trustee as specified in its charter) 95-

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Southwest Gas Holdings, Inc.

Southwest Gas Provides Leadership Update For Centuri Search for CEO Commences; Paul Daily to Retire as Chief Executive Officer Upon Appointment of Successor Southwest Gas Continuing to Advance Centuri Separation

Exhibit 99.1 Southwest Gas Provides Leadership Update For Centuri Search for CEO Commences; Paul Daily to Retire as Chief Executive Officer Upon Appointment of Successor Southwest Gas Continuing to Advance Centuri Separation LAS VEGAS, November 27, 2023 – Southwest Gas Holdings, Inc. (NYSE: SWX) (“Southwest Gas” or the “Company”) announced today that Paul M. Daily has informed the Company of his i

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) November 20, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

Amended and Restated Cooperation Agreement, dated as of November 21, 2023, by and among the Icahn Group and Southwest Gas Holdings, Inc.

Exhibit 10.1 Execution Version AMENDED AND RESTATED COOPERATION AGREEMENT This Amended and Restated Cooperation Agreement, dated as of November 21, 2023 (this “Agreement”), is by and among the persons and entities listed on Schedule A (collectively, the “Icahn Group”, and each individually a “member” of the Icahn Group) and Southwest Gas Holdings, Inc. (the “Company”). RECITALS WHEREAS, the Icahn

SWX / Southwest Gas Holdings Inc / ICAHN CARL C - SC 13D/A Activist Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment 7)* Southwest Gas Holdings, Inc. (Name of Issuer) Common Stock, Par Value $1.00 per share (Title of Class of Securities) 844895102 (CUSIP Number) Jesse A. Lynn Chief Operating Officer Icahn Capital LP 16690 Collins Avenue, PH-1 Sunny Isles Beach, FL 33160 (305) 422-4100 (Name

Entry into a Material Definitive Agreement, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) November 21, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) November 13, 2023 SOUTHWEST GAS HO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) November 13, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

Amendment No. 3 to Second Amended and Restated Centuri Credit Agreement

EX-10.1 Exhibit 10.1 EXECUTION VERSION THIRD AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT Dated as of November 13, 2023 This THIRD AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT (this “Amendment”) is by and among CENTURI GROUP, INC., a Nevada corporation (the “Company”), and each Additional Borrower that becomes a party thereto in accordance with Section 5.17 thereto, as US

Section 906 Certifications–Southwest Gas Corporation

Exhibit 32.02 SOUTHWEST GAS CORPORATION CERTIFICATION In connection with the periodic report of Southwest Gas Corporation on Form 10-Q for the period ended September 30, 2023 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the Chief Executive Officer of Southwest Gas Corporation, hereby certify as of the date hereof, solely for purposes of Title 18, Chapter

Section 906 Certifications–Southwest Gas Holdings, Inc.

Exhibit 32.01 SOUTHWEST GAS HOLDINGS, INC. CERTIFICATION In connection with the periodic report of Southwest Gas Holdings, Inc. (the “Company”) on Form 10-Q for the period ended September 30, 2023 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the President and Chief Executive Officer of the Company, hereby certify as of the date hereof, solely for purpose

for Southwest Gas Holdings, Inc. Directors and Officers

INDEMNIFICATION AGREEMENT This Indemnification Agreement (this “Agreement”) is made as of the day of , 2023 by and between Southwest Gas Holdings, Inc.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) November 8, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or orga

Section 302 Certifications–Southwest Gas Corporation

Exhibit 31.02 Certification of Southwest Gas Corporation I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements we

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 ☐ TRANSITION REPORT PURSUANT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number Exact name of registrant as specified in its charter and prin

Southwest Gas Holdings, Inc. Reports Third Quarter 2023 Financial Results Delivers Strong Third Quarter Growth in Utility and Centuri Net Income Increases 2023 Utility Earnings and Capital Expenditures Guidance and Reaffirms 2023 Centuri Revenue and

For Immediate Release November 8, 2023 Southwest Gas Holdings, Inc. Reports Third Quarter 2023 Financial Results Delivers Strong Third Quarter Growth in Utility and Centuri Net Income Increases 2023 Utility Earnings and Capital Expenditures Guidance and Reaffirms 2023 Centuri Revenue and EBITDA Margin Guidance LAS VEGAS – November 8, 2023 – Southwest Gas Holdings, Inc. (NYSE: SWX) (“Southwest Gas”

Section 302 Certifications–Southwest Gas Holdings, Inc.

Exhibit 31.01 Certification of Southwest Gas Holdings, Inc. I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Holdings, Inc.; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such stateme

for Southwest Gas Corporation Directors and Officers

INDEMNIFICATION AGREEMENT This Indemnification Agreement (this “Agreement”) is made as of the day of , 2023 by and between Southwest Gas Corporation, a California corporation, (the “Company”) and (the “Indemnitee”), a director or officer of the Company.

Certificate of Designations of the Series A Junior Participating Preferred Stock

EX-3.1 Exhibit 3.1 CERTIFICATE OF DESIGNATIONS of SERIES A JUNIOR PARTICIPATING PREFERRED STOCK of SOUTHWEST GAS HOLDINGS, INC. (Pursuant to Section 151 of the Delaware General Corporation Law) Southwest Gas Holdings, Inc., a corporation organized and existing under the General Corporation Law of the State of Delaware (hereinafter called the “Corporation”), hereby certifies that the following reso

Tax-Free Spin Protection Plan, dated November 5, 2023, between Southwest Gas Holdings, Inc. and Equiniti Trust Company, LLC, as Rights Agent

Exhibit 4.1 TAX-FREE SPIN PROTECTION PLAN by and between Southwest Gas Holdings, Inc. and Equiniti Trust Company, LLC as Rights Agent Dated as of November 5, 2023 TABLE OF CONTENTS Page 1. Certain Definitions 2 2. Appointment of Rights Agent 8 3. Issuance of Rights Certificates 9 4. Form of Rights Certificates 10 5. Countersignature and Registration 11 6. Transfer, Split Up, Combination and Exchan

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 Southwest Gas Holdings, Inc. (Exact name of reg

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 Southwest Gas Holdings, Inc. (Exact name of registrant as specified in its charter) Delaware 81-3881866 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identificatio

Regulation FD Disclosure, Entry into a Material Definitive Agreement

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) November 3, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or orga

Southwest Gas Holdings Announces Actions to Help Preserve Company’s Ability to Effectuate a Tax-Free Separation of Centuri and Provides Update to Private Letter Ruling Request Adopts Tax-Free Spin Protection Plan as it Considers Additional Centuri Se

Exhibit 99.1 Southwest Gas Holdings Announces Actions to Help Preserve Company’s Ability to Effectuate a Tax-Free Separation of Centuri and Provides Update to Private Letter Ruling Request Adopts Tax-Free Spin Protection Plan as it Considers Additional Centuri Separation Alternatives LAS VEGAS – November 6, 2023 – Southwest Gas Holdings, Inc. (NYSE: SWX) (“Southwest Gas” or the “Company”) today an

Current Report

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) October 20, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or orga

Amendment to Amended and Restated Bylaws of Southwest Gas Holdings, Inc., effective October 20, 2023. Incorporated herein by reference to Exhibit 3.1 to Form 8-K dated October 25, 2023, File No. 001-37976.

Exhibit 3.1 AMENDMENT TO BYLAWS SOUTHWEST GAS HOLDINGS, INC. a Delaware corporation Effective as of October 20, 2023, the Amended and Restated Bylaws (the “Bylaws”) of Southwest Gas Holdings, Inc. (the “Corporation”) are hereby amended as follows: 1. by adding, at the end of Section 3.3(a) of the Bylaws, the following sentence: “Notwithstanding anything to the contrary in these Bylaws, with respec

SWX / Southwest Gas Holdings Inc / Corvex Management LP Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. )* SOUTHWEST GAS HOLDINGS, INC. (Name of Issuer) Common Stock, par value $1 per share (Title of Class of Securities) 844895102 (CUSIP Number) Keith Meister Patrick J. Dooley, Esq. Corvex Management LP 667 Madison Avenue New York, NY 10065 (212) 474-6700 COPI

Section 302 Certifications–Southwest Gas Holdings, Inc.

Exhibit 31.01 Certification of Southwest Gas Holdings, Inc. I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Holdings, Inc.; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such stateme

Section 302 Certifications–Southwest Gas Corporation

Exhibit 31.02 Certification of Southwest Gas Corporation I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements we

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) August 9, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 ☐ TRANSITION REPORT PURSUANT TO S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number Exact name of registrant as specified in its charter and principal

Second Amendment to Second Amended and Restated Centuri Credit Agreement

Execution Version SECOND AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT Dated as of May 31, 2022 This SECOND AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT (this “Amendment”) is by and among CENTURI GROUP, INC.

Southwest Gas Holdings, Inc. Reports Second Quarter 2023 Financial Results Delivering Strong Second Quarter for Utility Net Income and Centuri Revenue Reaffirming 2023 Utility Earnings Guidance and 2023 Centuri Revenue and EBITDA Margin Guidance

For Immediate Release August 9, 2023 Southwest Gas Holdings, Inc. Reports Second Quarter 2023 Financial Results Delivering Strong Second Quarter for Utility Net Income and Centuri Revenue Reaffirming 2023 Utility Earnings Guidance and 2023 Centuri Revenue and EBITDA Margin Guidance LAS VEGAS – August 9, 2023 – Southwest Gas Holdings, Inc. (NYSE: SWX) (“Southwest Gas” or “Company”) today reported s

Section 906 Certifications–Southwest Gas Corporation

Exhibit 32.02 SOUTHWEST GAS CORPORATION CERTIFICATION In connection with the periodic report of Southwest Gas Corporation on Form 10-Q for the period ended June 30, 2023 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the Chief Executive Officer of Southwest Gas Corporation, hereby certify as of the date hereof, solely for purposes of Title 18, Chapter 63,

Section 906 Certifications–Southwest Gas Holdings, Inc.

Exhibit 32.01 SOUTHWEST GAS HOLDINGS, INC. CERTIFICATION In connection with the periodic report of Southwest Gas Holdings, Inc. (the “Company”) on Form 10-Q for the period ended June 30, 2023 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the President and Chief Executive Officer of the Company, hereby certify as of the date hereof, solely for purposes of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) July 17, 2023 Commission File Numb

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) July 17, 2023 Commission File Number Exact name of registrant as specified in its charter and principal office address and telephone number State of Incorporation I.R.S. Employer Ident

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 11-K ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 Commission file number 001-37976

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 11-K ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 Commission file number 001-37976 A. Full title of the plan and the address of the plan, if different from that of the issuer named below: SOUTHWEST GAS CORPORATION EMPLOYEES’ INVESTMENT PLAN B. N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 18, 2023 SOUTHWEST GAS HOLDING

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 18, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organiza

NATURAL GAS DISTRIBUTION SEGMENT RATEMAKING JURISDICTIONS AND REGULATORY AGENCIES Southwest Gas Corporation (Southwest Gas) is subject to regulation by the Arizona Corporation Commission (ACC), the Public Utilities Commission of Nevada (PUCN), and th

NATURAL GAS DISTRIBUTION SEGMENT RATEMAKING JURISDICTIONS AND REGULATORY AGENCIES Southwest Gas Corporation (Southwest Gas) is subject to regulation by the Arizona Corporation Commission (ACC), the Public Utilities Commission of Nevada (PUCN), and the California Public Utilities Commission (CPUC).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 ☐ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Form 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number Exact name of registrant as specified in its charter and principa

Section 906 Certifications–Southwest Gas Corporation

Exhibit 32.02 SOUTHWEST GAS CORPORATION CERTIFICATION In connection with the periodic report of Southwest Gas Corporation on Form 10-Q for the period ended March 31, 2023 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the Chief Executive Officer of Southwest Gas Corporation, hereby certify as of the date hereof, solely for purposes of Title 18, Chapter 63,

Section 302 Certifications–Southwest Gas Holdings, Inc.

Exhibit 31.01 Certification of Southwest Gas Holdings, Inc. I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Holdings, Inc.; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such stateme

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 4, 2023 SOUTHWEST GAS HOLDINGS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 4, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organizat

Section 906 Certifications–Southwest Gas Holdings, Inc.

Exhibit 32.01 SOUTHWEST GAS HOLDINGS, INC. CERTIFICATION In connection with the periodic report of Southwest Gas Holdings, Inc. (the “Company”) on Form 10-Q for the period ended March 31, 2023 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the President and Chief Executive Officer of the Company, hereby certify as of the date hereof, solely for purposes of

Section 302 Certifications–Southwest Gas Corporation

Exhibit 31.02 Certification of Southwest Gas Corporation I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements we

Southwest Gas Holdings, Inc. Reports First Quarter 2023 Financial Results Highest Quarterly Utility Net Income on Record; Highest First Quarter Revenues at Centuri Reaffirming 2023 Guidance

For Immediate Release May 9, 2023 Southwest Gas Holdings, Inc. Reports First Quarter 2023 Financial Results Highest Quarterly Utility Net Income on Record; Highest First Quarter Revenues at Centuri Reaffirming 2023 Guidance LAS VEGAS – May 9, 2023 – Southwest Gas Holdings, Inc. (NYSE: SWX) (“Southwest Gas” or the “Company”) today reported first quarter 2023 financial results. “We delivered strong

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 9, 2023 SOUTHWEST GAS HOLDINGS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) May 9, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organizat

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) April 25, 2023

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) April 25, 2023 Commission File Number Exact name of registrant as specified in its charter and principal office address and telephone number State of Incorporation I.R.S. Employer Iden

Amendment No. 2 to the Southwest Gas Holdings, Inc. Credit Facility.

EX-10.1 Exhibit 10.1 AMENDMENT NO. 2 TO AMENDED AND RESTATED REVOLVING CREDIT AGREEMENT AMENDMENT NO. 2 (this “Amendment”), dated as of April 25, 2023, to AMENDED AND RESTATED REVOLVING CREDIT AGREEMENT, dated as of April 10, 2020, among SOUTHWEST GAS HOLDINGS, INC. (the “Borrower”), the LENDERS party hereto and THE BANK OF NEW YORK MELLON, as Administrative Agent (the “Administrative Agent”). REC

Term Loan Credit Agreement, dated as of April 17, 2023, by and among Southwest Gas Holdings, Inc., the lenders from time to time party thereto, JPMorgan Chase Bank, N.A., as Administrative Agent, Bank of America, N.A. as Syndication Agent, JPMorgan Chase Bank, N.A., BofA Securities, Inc., Wells Fargo Bank, N.A. and U.S. Bank, National Association as Joint Lead Arrangers and Joint Bookrunners, and Wells Fargo Bank, N.A. and U.S. Bank, National Association as Co-Documentation Agents.

EX-10.1 Exhibit 10.1 TERM LOAN CREDIT AGREEMENT dated as of April 17, 2023 among SOUTHWEST GAS HOLDINGS, INC. as Borrower, THE LENDERS LISTED ON THE SIGNATURE PAGES HERETO and JPMORGAN CHASE BANK, N.A., as Administrative Agent, BANK OF AMERICA, N.A., as Syndication Agent, JPMORGAN CHASE BANK, N.A., BOFA SECURITIES, INC., WELLS FARGO BANK, N.A., and U.S. BANK, NATIONAL ASSOCIATION, as Joint Lead Ar

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) April 17, 2023 Commission File Num

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) April 17, 2023 Commission File Number Exact name of registrant as specified in its charter and principal office address and telephone number State of Incorporation I.R.S. Employer Iden

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) March 29, 2023 Commission File Num

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) March 29, 2023 Commission File Number Exact name of registrant as specified in its charter and principal office address and telephone number State of Incorporation I.R.S. Employer Iden

Performance Share Unit Grant Agreement Under the Southwest Gas Holdings, Inc. Omnibus Incentive Plan (EPS/ROE Shares)

PERFORMANCE SHARE UNIT GRANT AGREEMENT UNDER THE SOUTHWEST GAS HOLDINGS, INC. OMNIBUS INCENTIVE PLAN This Performance Share Unit Grant Agreement (“Grant Agreement”) is dated as of February , 2023, by and between Southwest Gas Holdings, Inc., a Delaware corporation (the "Company"), and ("Grantee"), pursuant to the Company's Omnibus Incentive Plan (the "Plan"). Capitalized terms that are used, but n

Centuri Grant Agreement for Time-Lapse Restricted Stock Units Under the Southwest Gas Holdings, Inc. Omnibus Incentive Plan

GRANT AGREEMENT FOR TIME-LAPSE RESTRICTED STOCK UNITS UNDER THE SOUTHWEST GAS HOLDINGS, INC.

Centuri Performance Share Unit Grant Agreement Under the Southwest Gas Holdings, Inc. Omnibus Incentive Plan

PERFORMANCE SHARE UNIT GRANT AGREEMENT UNDER THE SOUTHWEST GAS HOLDINGS, INC. OMNIBUS INCENTIVE PLAN This Performance Share Unit Grant Agreement (“Grant Agreement”) is dated as of , 2023, by and between Centuri Group, Inc. (“Centuri”), Southwest Gas Holdings, Inc. (the "Company"), and ("Grantee"), pursuant to the Company's Omnibus Incentive Plan (the "Plan"). Capitalized terms that are used, but n

Grant Agreement for Time-Lapse Restricted Stock Units Under the Southwest Gas Holdings, Inc. Omnibus Incentive Plan

GRANT AGREEMENT FOR TIME-LAPSE RESTRICTED STOCK UNITS UNDER THE SOUTHWEST GAS HOLDINGS, INC.

Performance Share Unit Grant Agreement Under the Southwest Gas Holdings, Inc. Omnibus Incentive Plan (UNI/ROE Shares)

PERFORMANCE SHARE UNIT GRANT AGREEMENT UNDER THE SOUTHWEST GAS HOLDINGS, INC. OMNIBUS INCENTIVE PLAN This Performance Share Unit Grant Agreement (“Grant Agreement”) is dated as of February , 2023, by and between Southwest Gas Holdings, Inc., a Delaware corporation (the "Company"), and ("Grantee"), pursuant to the Company's Omnibus Incentive Plan (the "Plan"). Capitalized terms that are used, but n

SWX / Southwest Gas Holdings Inc / ICAHN CARL C - SC 13D/A Activist Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment 6)* Southwest Gas Holdings, Inc. (Name of Issuer) Common Stock, Par Value $1.00 per share (Title of Class of Securities) 844895102 (CUSIP Number) Jesse A. Lynn Chief Operating Officer Icahn Capital LP 16690 Collins Avenue, PH-1 Sunny Isles Beach, FL 33160 (305) 422-4100 (Name

Underwriting Agreement, dated March 21, 2023, by and among Southwest Gas Corporation and BofA Securities, Inc., J.P. Morgan Securities, LLC, TD Securities (USA) LLC, U.S. Bancorp Investments, Inc. and Wells Fargo Securities, LLC, as representatives of the underwriters named therein.

EX-1.1 Exhibit 1.1 SOUTHWEST GAS CORPORATION $300,000,000 5.450% Senior Notes due 2028 UNDERWRITING AGREEMENT March 21, 2023 BOFA SECURITIES, INC. J.P. MORGAN SECURITIES LLC TD SECURITIES (USA) LLC U.S. BANCORP INVESTMENTS, INC. WELLS FARGO SECURITIES, LLC As Representatives of the several Underwriters listed in Schedule 1 hereto c/o BofA Securities, Inc. One Bryant Park New York, New York 10036 c

Fifth Supplemental Indenture, dated March 23, 2023, by and between Southwest Gas Corporation and The Bank of New York Mellon Trust Company, N.A., as Trustee.

EX-4.1 Exhibit 4.1 SOUTHWEST GAS CORPORATION, as Issuer and The Bank of New York Mellon Trust Company, N.A., as Trustee FIFTH SUPPLEMENTAL INDENTURE Dated as of March 23, 2023 5.450% SENIOR NOTES DUE 2028 CROSS-REFERENCE TABLE Certain Sections of this Indenture relating to Sections 310 through 318, inclusive, of the Trust Indenture Act of 1939, as amended: Trust Indenture Act Section Indenture Sec

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) March 21, 2023 Commission File Number Exact name of registrant as specified in its charter and principal office address and telephone number State of Incorporation I.R.S. Employer Iden

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) x Definitive Proxy Statement o Definitive Additional Materials o Soliciting Material Under Rule 14a-12 Southwest Gas Holdings, Inc.

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) o Definitive Proxy Statement x Definitive Additional Materials o Soliciting Material Under Rule 14a-12 Southwest Gas Holdings, Inc.

SWX / Southwest Gas Holdings Inc / ICAHN CARL C - SC 13D/A Activist Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment 5)* Southwest Gas Holdings, Inc. (Name of Issuer) Common Stock, Par Value $1.00 per share (Title of Class of Securities) 844895102 (CUSIP Number) Jesse A. Lynn Chief Operating Officer Icahn Capital LP 16690 Collins Avenue, PH-1 Sunny Isles Beach, FL 33160 (305) 422-4100 (Name

SWX / Southwest Gas Holdings Inc / ICAHN CARL C - SC 13D/A Activist Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment 4)* Southwest Gas Holdings, Inc. (Name of Issuer) Common Stock, Par Value $1.00 per share (Title of Class of Securities) 844895102 (CUSIP Number) Jesse A. Lynn Chief Operating Officer Icahn Capital LP 16690 Collins Avenue, PH-1 Sunny Isles Beach, FL 33160 (305) 422-4100 (Name

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) March 8, 2023 SOUTHWEST GAS HOLDIN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) March 8, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organiz

Underwriting Agreement, dated March 8, 2023, by and among Southwest Gas Holdings, Inc. and J.P. Morgan Securities LLC and BofA Securities, Inc., as representatives of the several underwriters named in Schedule 1 thereto.

EX-1.1 Exhibit 1.1 Execution Version SOUTHWEST GAS HOLDINGS, INC. 3,576,180 SHARES OF COMMON STOCK UNDERWRITING AGREEMENT March 8, 2023 J.P. MORGAN SECURITIES LLC BOFA SECURITIES, INC. As Representatives of the several Underwriters listed in Schedule 1 hereto c/o J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 c/o BofA Securities, Inc. One Bryant Park New York, New York 1003

3,576,180 Shares Common Stock

424B5 Table of Contents Filed Pursuant to Rule 424(b)(5) Registration No. 333-251074 PROSPECTUS SUPPLEMENT (To Prospectus dated December 2, 2020) 3,576,180 Shares Common Stock We are offering 3,576,180 shares of our common stock, $1.00 par value per share. Our common stock is listed on the New York Stock Exchange (or the “NYSE”) under the symbol “SWX,” and the last reported sale price of our commo

Calculation of Filing Fee (Form Type) Southwest Gas Holdings, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule

EX-FILING FEES 2 d432464dexfilingfees.htm EX-FILING FEES Exhibit 107 Calculation of Filing Fee 424(b)(5) (Form Type) Southwest Gas Holdings, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered(1) Proposed Maximum Offering Price Per Share(2) Maxim

SOUTHWEST GAS HOLDINGS, INC. UNAUDITED PRO FORMA COMBINED FINANCIAL INFORMATION

EX-99.1 Exhibit 99.1 SOUTHWEST GAS HOLDINGS, INC. UNAUDITED PRO FORMA COMBINED FINANCIAL INFORMATION On December 15, 2022, Southwest Gas Holdings, Inc (the “Company”) issued a press release announcing the decision of its Board of Directors to pursue a spin-off of Centuri Group, Inc., a wholly owned subsidiary of the Company, into a standalone independent public company (the “Spin-off”). The Spin-o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) March 7, 2023 SOUTHWEST GAS HOLDIN

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) March 7, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or organiz

Subject to Completion Preliminary Prospectus Supplement dated March 7, 2023

424B5 Table of Contents The information contained in this preliminary prospectus supplement is not complete and may be changed.

Amended Change in Control Agreement by and between Southwest Gas Holdings, Inc., Southwest Gas Corporation and Karen Haller.

AMENDED AND RESTATED CHANGE IN CONTROL AGREEMENT THIS AMENDED AND RESTATED CHANGE IN CONTROL AGREEMENT (this “Agreement”) is entered into and effective as of the 18th day of May, 2022 (the “Effective Date”), among SOUTHWEST GAS CORPORATION, a California corporation (“Southwest”), SOUTHWEST GAS HOLDINGS, INC.

First Amendment to Centuri Credit Facility Agreement.

EXECUTION VERSION FIRST AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT Dated as of November 4, 2022 This FIRST AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT (this “Amendment”) is by and among CENTURI GROUP, INC.

Consent of PricewaterhouseCoopers LLP, an independent registered public accounting firm - Southwest Gas Holdings, Inc.

Exhibit 23.01 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We hereby consent to the incorporation by reference in the Registration Statements on Form S-3 (No. 333-251074) and Form S-8 (Nos. 333-215145-01, 333-155581-01, 333-215150-01, 333-185354-01, 333-222048) of Southwest Gas Holdings, Inc. of our report dated February 28, 2023 relating to the financial statements and the effectivene

List of subsidiaries - Southwest Gas Holdings, Inc.

EXHIBIT 21.01 SOUTHWEST GAS HOLDINGS, INC. LIST OF SUBSIDIARIES OF THE REGISTRANT AT DECEMBER 31, 2022 SUBSIDIARY NAME STATE OF INCORPORATION OR ORGANIZATION TYPE Southwest Gas Holdings, Inc. Delaware Southwest Gas Utility Group, Inc. California Southwest Gas Corporation California Utility Financial Corp. Nevada The Southwest Companies Nevada Southwest Gas Transmission Company Limited partnership

Annual Report to Stockholders incorporated by reference to the Form 10-K.

Exhibit 13.01 Management’s Discussion and Analysis of Financial Condition and Results of Operations About Southwest Gas Holdings, Inc. Southwest Gas Holdings, Inc. is a holding company that owns all of the shares of common stock of Southwest Gas Corporation (“Southwest” or the “natural gas distribution” segment), all of the shares of common stock of Centuri Group, Inc. (“Centuri” or the “utility i

Section 302 Certifications–Southwest Gas Holdings, Inc.

Exhibit 31.01 Certification of Southwest Gas Holdings, Inc. I, Karen S. Haller, certify that: 1. I have reviewed this annual report on Form 10-K of Southwest Gas Holdings, Inc.; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statemen

Section 906 Certifications–Southwest Gas Holdings, Inc.

Exhibit 32.01 SOUTHWEST GAS HOLDINGS, INC. CERTIFICATION In connection with the periodic report of Southwest Gas Holdings, Inc. (the “Company”) on Form 10-K for the period ended December 31, 2022 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the President and Chief Executive Officer of the Company, hereby certify as of the date hereof, solely for purposes

Section 906 Certifications–Southwest Gas Corporation.

Exhibit 32.02 SOUTHWEST GAS CORPORATION CERTIFICATION In connection with the periodic report of Southwest Gas Corporation on Form 10-K for the period ended December 31, 2022 as filed with the Securities and Exchange Commission (the “Report”), I, Karen S. Haller, the Chief Executive Officer of Southwest Gas Corporation, hereby certify as of the date hereof, solely for purposes of Title 18, Chapter

Southwest Gas Holdings, Inc. Reports 2022 Financial Results Constructive Rate Case Outcomes in Arizona and Nevada Completed Sale of MountainWest Unlocking Value and Balance Sheet Flexibility through Spin of Centuri Managing Costs and Delivering Earni

For Immediate Release February 28, 2023 Southwest Gas Holdings, Inc. Reports 2022 Financial Results Constructive Rate Case Outcomes in Arizona and Nevada Completed Sale of MountainWest Unlocking Value and Balance Sheet Flexibility through Spin of Centuri Managing Costs and Delivering Earnings Growth in 2023 LAS VEGAS – February 28, 2023 – Southwest Gas Holdings, Inc. (NYSE: SWX) (“Southwest Gas” o

Section 302 Certifications–Southwest Gas Corporation.

Exhibit 31.02 Certification of Southwest Gas Corporation I, Karen S. Haller, certify that: 1. I have reviewed this annual report on Form 10-K of Southwest Gas Corporation; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements wer

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 28, 2023 SOUTHWEST GAS HO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 28, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal period ended December 31, 2022 ☐ TRANSITION REPORT PURSUANT TO SEC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal period ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File Number Exact name of registrant as specified in its charter and principal o

Consent of PricewaterhouseCoopers LLP, an independent registered public accounting firm - Southwest Gas Corporation.

Exhibit 23.02 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We hereby consent to the incorporation by reference in the Registration Statement on Form S-3 (No. 333-251074-01) of Southwest Gas Corporation of our report dated February 28, 2023 relating to the financial statements, which appears in the 2022 Annual Report to Stockholders, which is incorporated by reference in this Annual Rep

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 14, 2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 14, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of

SOUTHWEST GAS HOLDINGS, INC. UNAUDITED PRO FORMA COMBINED FINANCIAL INFORMATION

EX-99.1 Exhibit 99.1 SOUTHWEST GAS HOLDINGS, INC. UNAUDITED PRO FORMA COMBINED FINANCIAL INFORMATION On February 14, 2023, Southwest Gas Holdings, Inc. (the “Company”) completed its previously announced sale of all of the equity interests in MountainWest Pipelines Holding Company (“MountainWest”) pursuant to the terms of that certain Purchase and Sale Agreement (the “Purchase Agreement”), dated as

Southwest Gas Holdings Announces Closing of Sale of MountainWest to Williams

Exhibit 99.1 For Immediate Release February 14, 2023 Southwest Gas Holdings Announces Closing of Sale of MountainWest to Williams LAS VEGAS, February 14, 2023 – Southwest Gas Holdings, Inc. (NYSE: SWX) (“Southwest Gas” or the “Company”) today announced that it has closed the previously announced sale of MountainWest Pipelines Holding Company (“MountainWest”) to Williams (NYSE: WMB), in a $1.5 bill

Regulation FD Disclosure, Financial Statements and Exhibits, Completion of Acquisition or Disposition of Assets

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) February 14, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

SWX / Southwest Gas Corp. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv01931-southwestgasholdings.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 8)* Name of issuer: Southwest Gas Holdings Inc. Title of Class of Securities: Common Stock CUSIP Number: 844895102 Date of Event Which Requires Filing of this Statement: December 30, 2022 Check the appropriate bo

364-Day Term Loan Credit Agreement, dated as of January 20, 2023, by and among Southwest Gas Corporation, JPMorgan Chase Bank, N.A., as Administrative Agent, and the Lenders from time to time party thereto.

Exhibit 10.1 Execution Version 364-DAY TERM LOAN CREDIT AGREEMENT dated as of January 20, 2023 among SOUTHWEST GAS CORPORATION, as Borrower, THE LENDERS LISTED ON THE SIGNATURE PAGES HERETO and JPMORGAN CHASE BANK, N.A., as Administrative Agent, and JPMORGAN CHASE BANK, N.A., as Sole Lead Arranger and Bookrunner TABLE OF CONTENTS ARTICLE I DEFINITIONS 1 SECTION 1.01 Definitions 1 ARTICLE II THE CR

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) January 20, 2023 Commission File Number Exact name of registrant as specified in its charter and principal office address and telephone number State of Incorporation I.R.S. Employer Id

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A/A Amendment No. 2 FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 Southwest Gas Holdings, Inc.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A/A Amendment No. 2 FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 Southwest Gas Holdings, Inc. (Exact name of registrant as specified in its charter) Delaware 81-3881866 (State or other jurisdiction of incorporation or organization) (I.R.S. Empl

As filed with the Securities and Exchange Commission on January 13, 2023.

As filed with the Securities and Exchange Commission on January 13, 2023. Registration No. 333-168731-01 Registration No. 333-200835-01 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 POST-EFFECTIVE AMENDMENT NO. 3 TO: FORM S-8 REGISTRATION STATEMENT NO. 333-168731-01 FORM S-8 REGISTRATION STATEMENT NO. 333-200835-01 UNDER THE SECURITIES ACT OF 1933 Southwest Gas Holdings,

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) January 13, 2023 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or orga

As filed with the Securities and Exchange Commission on January 13, 2023.

As filed with the Securities and Exchange Commission on January 13, 2023. Registration No. 333-168731-01 Registration No. 333-200835-01 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 POST-EFFECTIVE AMENDMENT NO. 3 TO: FORM S-8 REGISTRATION STATEMENT NO. 333-168731-01 FORM S-8 REGISTRATION STATEMENT NO. 333-200835-01 UNDER THE SECURITIES ACT OF 1933 Southwest Gas Holdings,

EX-99.25

NOTIFICATION OF THE REMOVAL FROM LISTING AND REGISTRATION OF THE STATED SECURITIES The New York Stock Exchange hereby notifies the SEC of its intention to remove the entire class of the stated securities from listing and registration on the Exchange at the opening of business on January 24, 2023, pursuant to the provisions of Rule 12d2-2 (a).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13

15-12G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File Number 001-37976 Southwest Gas Holdings, Inc. (Exact name of registrant as s

Certificate of Elimination of Series A Junior Participating Preferred Stock of Southwest Gas Holdings, Inc.

Exhibit 3.1 CERTIFICATE OF ELIMINATION of SERIES A JUNIOR PARTICIPATING PREFERRED STOCK of SOUTHWEST GAS HOLDINGS, INC. Pursuant to Section 151(g) of the Delaware General Corporation Law I, Thomas E. Moran, Vice President, General Counsel and Corporate Secretary of Southwest Gas Holdings, Inc. (the “Company”), a corporation organized and existing under the General Corporation Law of the State of D

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) December 30, 2022 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

Southwest Gas Simplifies Corporate Structure to Maximize Stockholder Value Reaches Agreement to Sell MountainWest Pipelines for $1.5 Billion to Williams Decides to Spin Off Centuri, Creating Two Focused, Independent Companies Centuri, a Leading Indep

EX-99.1 Exhibit 99.1 FOR IMMEDIATE RELEASE Southwest Gas Simplifies Corporate Structure to Maximize Stockholder Value Reaches Agreement to Sell MountainWest Pipelines for $1.5 Billion to Williams Decides to Spin Off Centuri, Creating Two Focused, Independent Companies Centuri, a Leading Independent Utility Infrastructure Services Business, Positioned for Continued Profitable Growth at the Forefron

Purchase and Sale Agreement, dated as of December 14, 2022, by and between Williams Partners Operating LLC, Southwest Gas Holdings, Inc. and MountainWest Pipelines Holding Company

EX-2.1 Exhibit 2.1 PURCHASE AGREEMENT by and among WILLIAMS PARTNERS OPERATING LLC, SOUTHWEST GAS HOLDINGS, INC. and MOUNTAINWEST PIPELINES HOLDING COMPANY dated as of December 14, 2022 TABLE OF CONTENTS Page ARTICLE I PURCHASE AND SALE 1 Section 1.1. Purchase and Sale 1 Section 1.2. Closing 1 Section 1.3. Purchase Consideration 2 Section 1.4. Estimated Closing Statement; Determination of Estimate

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) December 14, 2022 SOUTHWEST GAS HO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) December 14, 2022 SOUTHWEST GAS HOLDINGS, INC. (Exact name of registrant as specified in its charter) Delaware 001-37976 81-3881866 (State or other jurisdiction of incorporation or org

Fourth Supplemental Indenture, dated December 1, 2022, by and between Southwest Gas Corporation and The Bank of New York Mellon Trust Company, N.A., as Trustee.

Exhibit 4.1 SOUTHWEST GAS CORPORATION, as Issuer and The Bank of New York Mellon Trust Company, N.A., as Trustee FOURTH SUPPLEMENTAL INDENTURE Dated as of December 1, 2022 5.800% SENIOR NOTES DUE 2027 CROSS-REFERENCE TABLE Certain Sections of this Indenture relating to Sections 310 through 318, inclusive, of the Trust Indenture Act of 1939, as amended: Trust Indenture Act Section Indenture Section

Underwriting Agreement, dated November 29, 2022, by and among Southwest Gas Corporation and BNY Mellon Capital Markets, LLC, BofA Securities, Inc., J.P. Morgan Securities LLC, and Wells Fargo Securities, LLC, as representatives of the underwriters named therein.

Exhibit 1.1 SOUTHWEST GAS CORPORATION $300,000,000 5.800% Senior Notes due December 1, 2027 UNDERWRITING AGREEMENT November 29, 2022 BNY MELLON CAPITAL MARKETS, LLC BOFA SECURITIES, INC. J.P. MORGAN SECURITIES LLC WELLS FARGO SECURITIES, LLC As Representatives of the several Underwriters listed in Schedule 1 hereto c/o BNY Mellon Capital Markets, LLC 240 Greenwich Street, 3W New York, New York 102

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported) November 29, 2022 Commission File Number Exact name of registrant as specified in its charter and principal office address and telephone number State of Incorporation I.R.S. Employer I

Section 302 Certifications–Southwest Gas Corporation

Exhibit 31.02 Certification of Southwest Gas Corporation I, Karen S. Haller, certify that: 1.I have reviewed this quarterly report on Form 10-Q of Southwest Gas Corporation; 2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements we