Southwest Gas : Notice of 2024 Annual Meeting of Stockholders and Proxy Statement

2024 Proxy Statement

Notice of 2024 Annual Meeting of Stockholders

To Be Held on May 2, 2024

March 18, 2024

Dear Stockholder:

You are cordially invited to the Annual Meeting of Stockholders of Southwest Gas Holdings, Inc. scheduled to be held on May 2, 2024 at 8:30 a.m. PDT in a completely virtual format. Please see page 1 of the Proxy Statement for instructions regarding access to the virtual Annual Meeting.

The Notice of Annual Meeting of Stockholders and the Proxy Statement contain details of the business to be conducted at the Annual Meeting. Your Board of Directors asks you to support the Board of Directors' director nominees and to follow its recommendations with respect to the other proposals set forth in the Proxy Statement.

It is important that your shares are represented and voted at the meeting regardless of the number of shares you own and whether or not you plan to attend. Accordingly, we request you vote, as instructed in the Notice of Internet Availability of Proxy Materials or Proxy Card, online, as promptly as possible. If you received only a notice in the mail or by email, you may also request a paper Proxy Card to submit your vote by mail, if you prefer. However, we encourage you to vote online or by telephone because it is more convenient, conserves natural resources and reduces printing costs and postage fees.

Your interest and participation in the affairs of our Company are greatly appreciated.

Sincerely yours,

Karen S. Haller

President and Chief Executive Officer

8360 S. Durango Drive

Las Vegas, Nevada 89113

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

March 18, 2024

NOTICE IS HEREBY GIVEN that the Annual Meeting of Stockholders of Southwest Gas Holdings, Inc. ("we," "us," "our," or the "Company") will be held on May 2, 2024, at 8:30 a.m. PDT in a completely virtual format, for the following purposes:

1. To elect eleven directors of the Company;
2. To approve, on a non-binding, advisory basis, the Company's executive compensation;
3. To approve the Company's 2024 Omnibus Incentive Plan;
4. To approve the Company's Tax-Free Spin Protection Plan;
5. To ratify the selection of PricewaterhouseCoopers LLP as the independent registered public accounting firm for the Company for fiscal year 2024; and
6. To transact such other business as may properly come before the meeting or any adjournment thereof.

The Board of Directors of the Company established March 4, 2024 as the record date for the determination of stockholders entitled to vote at the Annual Meeting and to receive notice thereof.

HOW TO VOTE

Please review the proxy statement and vote, at your earliest convenience, using any of the following methods:

Call the phone number listed on your Proxy Card to vote BY TELEPHONE.

Visit the website listed on your Proxy Card to vote ONLINE.

Sign, date and return your Proxy Card in the provided postage-paid envelope to vote BY MAIL.

Access the virtual meeting to vote by ballot. See "How Do I Attend the Annual Meeting?" (page 1) for instructions.

Your vote is very important. Please submit your proxy even if you plan to attend the Annual Meeting virtually, so that if you are unable to attend the Annual Meeting your shares can still be voted. Voting now will not limit your right to change your vote or to attend the Annual Meeting. If you attend the Annual Meeting virtually and decide to vote by ballot at the Annual Meeting, such vote will revoke any prior proxy you may have submitted. If your shares are held in the name of a bank, broker or other holder of record, you may vote at the Annual Meeting only if you provide a legal proxy from such bank, broker or other holder of record.

By Order of the Board of Directors,

Thomas E. Moran

Vice President, General Counsel and Corporate Secretary

Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting to be held on May 2, 2024: Pursuant to rules promulgated by the U.S. Securities and Exchange Commission ("SEC"), we have elected to provide access to our proxy materials by notifying you of the availability of our proxy materials on the internet. On or about March 18, 2024, an important Notice Regarding the Availability of Proxy Materials (the "Notice of Internet Availability") will be sent to our stockholders of record, and a paper copy of the proxy materials will be sent to Employee Investment Plan participants and those stockholders of record who have requested a paper copy. Brokers and other nominees who hold shares on behalf of beneficial owners will be sending their own similar notice regarding availability of proxy materials. In accordance with SEC rules, you may access our proxy materials and 2023 Annual Report to Stockholders at www.swgasholdings.com/proxymaterials, which provides for anonymous access. The Notice of Internet Availability also includes instructions for stockholders to request, at no charge, a printed copy of the proxy materials.

Important Notice Regarding the Virtual Annual Meeting: The virtual format of the Annual Meeting ensures that stockholders are afforded the same rights and opportunities to participate as they would have at an in-personmeeting, using online tools to ensure stockholder access and participation. For more information about the virtual Annual Meeting, see "General Information" in this Proxy Statement.

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TABLE OF CONTENTS
	Page
Invitation to 2024 Annual Meeting of Stockholders
Notice of Annual Meeting of Stockholders
Proxy Statement	1
General Information	1
Governance of the Company	6
Board of Directors	6
Board Leadership Structure	6
Cooperation Agreement	7
Risk Oversight	7
Analysis of Risk in Company Executive
Compensation Policies	8
Cybersecurity Oversight	8
ESG Practices and Oversight	8
Committees of the Board	11
Selection of Directors	12
Board Evaluation and Director Succession
Planning	13
Stockholder Engagement	13
Majority Voting Policy	14
Transactions with Related Persons	14
Compensation Committee Interlocks and
Insider Participation	15
Director Attendance at Annual Meetings . . .	15
Communications with Directors	15
Executive Officers	16
Securities Ownership by Directors, Director
Nominees, Executive Officers, and
Certain Beneficial Owners	17
Proposal 1 - Election of Directors	19
General	19
Vote Required	19
Names, Qualifications and Reasons for
Selection of Nominees	19
Executive Compensation	27
Compensation Discussion and Analysis	27
Executive Summary	27
Compensation Program Objectives, Key
Considerations and Principles	29
Compensation Program Administration . . . .	30
How We Determine Amounts Paid For Each
Element of Compensation	30
Consideration of 2023 Say-on-Pay Vote . . .	31
Details of Compensation Program	32
Directors and Officers Share Ownership
Guidelines	44
Pledging, Hedging and Other Transactions
in Company Securities	44
Policies and Practices Regarding Equity
Grants	45
Clawback Policy	45
Compensation Committee Report	46
Executive Compensation Tables	47
Summary Compensation Table (2023, 2022
and 2021)	47
Grants of Plan-Based Awards (2023)	49

Page

Outstanding Equity Awards at Fiscal

Year-End 2023 . . . . . . . . . . . . . . . . . . . . . . 50

Stock Vested During 2023 . . . . . . . . . . . . . . . 51

Pension Benefits . . . . . . . . . . . . . . . . . . . . . . . 51

Nonqualified Deferred Compensation

(2023) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Post-Termination Benefits . . . . . . . . . . . . . . . 53

Pay Ratio Disclosure . . . . . . . . . . . . . . . . . . . 56

Pay Versus Performance . . . . . . . . . . . . . . . . 57

Director Compensation . . . . . . . . . . . . . . . . . . . . . 64

2023 Director Compensation Table . . . . . . . 64

Director Compensation Narrative . . . . . . . . . 64

Proposal 2 - Advisory Vote To Approve the Company's Executive Compensation . . . . . . . . 66

Proposal 3 - Approval of the Company's 2024 Omnibus Incentive Plan . . . . . . . . . . . . . . . . . . . 67

Proposal 4 - Approval of the Company's

Tax-Free Spin Protection Plan . . . . . . . . . . . . . 78

Audit Committee Information . . . . . . . . . . . . . . . . . 81

Proposal 5 - Selection of Independent

Registered Public Accounting Firm . . . . . . . . . . 81

Audit Committee Report . . . . . . . . . . . . . . . . . . . . 83

Submission of Stockholder Proposals . . . . . . . . . 84

Other Matters to Come Before the Meeting . . . . . 84

Appendix A - 2024 Omnibus Incentive Plan . . . 85

Appendix B - Tax-Free Spin Protection Plan . . . 98

Southwest Gas Holdings 2024 Notice and Proxy i

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PROXY STATEMENT

ANNUAL MEETING OF STOCKHOLDERS

To Be Held on May 2, 2024

GENERAL INFORMATION

We are providing these proxy materials to you in connection with the solicitation of proxies by the Board of Directors (the "Board") of Southwest Gas Holdings, Inc. ("we," "us," "our," or the "Company") for the 2024 Annual Meeting of Stockholders (the "Annual Meeting") and for any adjournment or postponement of the Annual Meeting. The Annual Meeting will be held in a completely virtual format on May 2, 2024 at 8:30 a.m. PDT.

We are sending a Notice of Internet Availability of Proxy Materials and making this Proxy Statement, a form of Proxy Card and our 2023 Annual Report to Stockholders available to stockholders on our website at www.swgasholdings.com/proxymaterials on or about March 18, 2024. We also will be mailing these materials to Employee Investment Plan participants, and to those stockholders who request paper or e-mail copies of the proxy materials, on or about March 18, 2024.

What is the purpose of the Annual Meeting?

At the Annual Meeting, stockholders will act upon the matters outlined in the Notice of Annual Meeting of Stockholders and described in these materials, including:

• The election of eleven directors of the Company;
• The approval, on a non-binding, advisory basis, of the Company's executive compensation;
• The approval of the Company's 2024 Omnibus Incentive Plan;
• The approval of the Company's Tax-Free Spin Protection Plan;
• The ratification of the selection of PricewaterhouseCoopers LLP as the independent registered public accounting firm for the Company for fiscal year 2024; and
• The transaction of such other business as may properly come before the meeting or any adjournment thereof.

How do I attend the Annual Meeting?

The Annual Meeting will be a completely virtual meeting of stockholders. You can attend the Annual Meeting online, where you will be able to listen to the meeting live, submit questions and vote online, as long as you have pre-registered. Attendance at the Annual Meeting will be limited to stockholders of the Company as of March 4, 2024, the record date for the Annual Meeting, and guests of the Company. You will not be able to attend the Annual Meeting in person at a physical location.

In order to attend the virtual Annual Meeting, you will need to pre-register at least two hours before the Annual Meeting begins. To pre-register for the meeting, please go to https://register.proxypush.com/swx. You will need the control number found on the upper right-hand corner of the Proxy Card included in the proxy materials. After registering, you will receive a confirmation email. Approximately one hour prior to the start time of the meeting, you will receive another email containing a unique link providing access to the virtual Annual Meeting. The Annual Meeting will begin promptly at 8:30 a.m. PDT. Online access to the meeting will open at 8:15 a.m. PDT to allow time for stockholders to log-in and test their equipment. A countdown waiting page will be shown if you log-in before 8:15 a.m. PDT. All emails will be sent to the email address you provide during pre-registration. You will need the latest version of Chrome, Safari, Internet Explorer, Edge or Firefox. Please test your internet browser before the Annual Meeting to ensure compatibility. A toll-free phone number will be provided to access technical support for the virtual Annual Meeting.

Southwest Gas Holdings 2024 Notice and Proxy 1

Technical Disruptions. In the event of any technical disruptions or connectivity issues during the course of the Annual Meeting, please allow for some time for the meeting website to refresh automatically, and/or for the meeting operator to provide verbal updates.

Stockholder List. As required by Delaware law, we will make available a list of registered stockholders as of the record date for inspection by stockholders for any purpose germane to the Annual Meeting from April 22, 2024 through May 2, 2024 at our headquarters located at 8360 S. Durango Dr., Las Vegas, Nevada. If you wish to inspect the list, please submit your request, along with proof of ownership, by email to [e-mail]. As required by our Bylaws, the stockholder list will also be available electronically on the meeting website during the live webcast of the Annual Meeting.

Voting by Ballot at the Annual Meeting. Although the meeting webcast will begin at 8:30 a.m. PDT on

May 2, 2024, we encourage you to access the meeting site 15 minutes prior to the start time to allow ample time to log into the meeting webcast and test your computer system.

For street name stockholders who wish to vote by ballot at the Annual Meeting, you must also provide a legal proxy from your broker, bank or other custodian when submitting your ballot before the polls close at the Annual Meeting. Any voting instruction form you receive in connection with the Annual Meeting is not a legal proxy. Please also note that if you do request a legal proxy from your broker, bank or other agent, the issuance of the legal proxy will invalidate any prior voting instructions you have given and will prevent you from giving any further voting instructions to your broker, bank or custodian to vote on your behalf. Consequently, you will only be able to vote by ballot at the Annual Meeting or by submitting a validly executed Proxy Card together with your legal proxy in advance of the Annual Meeting. Your legal proxy, in electronic form (PDF, JPEG, GIF or PNG file format), must be submitted along with your ballot before the polls close at the Annual Meeting in order for your vote by ballot to count. Multiple legal proxies must be combined into one document for uploading at the Annual Meeting.

How can I submit questions prior to and during the Annual Meeting?

Prior to the Annual Meeting, stockholders may submit questions pertaining to the business of the meeting by emailing the Company's Corporate Secretary, Thomas Moran, at: [e-mail]. During the Annual Meeting, as well as 15 minutes prior to the start time, stockholders will also be able to submit questions through the online platform used for the Annual Meeting. As has been the case at prior Annual Meetings of Stockholders, the Company will respond to questions during the meeting or shortly after the meeting on our website as applicable. We will endeavor to answer as many questions submitted by stockholders as time permits. We reserve the right to edit questions to remove inappropriate language and to exclude questions regarding topics that are not pertinent to meeting matters. If we receive substantially similar questions, we may group such questions together and provide a single response.

Who is entitled to vote at the Annual Meeting?

Only stockholders of record at the close of business on March 4, 2024, the record date for the Annual Meeting, are entitled to receive notice of and to vote at the Annual Meeting. If you are a stockholder of record on that date, you are entitled to vote all of the shares that you held on that date at the Annual Meeting, or any adjournment or postponement of the Annual Meeting. No dissenters' rights are provided under the Delaware General Corporation Law, our Articles of Incorporation, or our Bylaws with respect to any of the proposals described in this Proxy Statement.

How many votes do I have?

You have one vote for each share of the Company's common stock ("Common Stock") you owned as of the record date for the Annual Meeting.

How do I vote?

If your shares are registered directly in your name, you are the holder of record of those shares and can vote your shares either by proxy, whether or not you attend the virtual Annual Meeting, or by ballot by attending the virtual Annual Meeting. Whether or not you plan to attend the virtual Annual Meeting, we encourage you to submit your proxy promptly to ensure that your votes are counted. You may still attend the virtual Annual Meeting and vote by ballot even if you have already submitted a proxy.

2 Southwest Gas Holdings 2024 Notice and Proxy