COMFORT SYSTEMS USA INC

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934 (Amendment No. )

Comfort Systems USA, Inc.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

ANNUAL STOCKHOLDER MEETING FRIDAY, May 16, 2025 11:00AM CENTRAL TIME THE ST. REGIS HOUSTON 1919 Briar Oaks Lane, HOUSTON, TEXAS 77027 We build legacies. Comfort Systems USA is composed of more than 45 operating companies in approximately 180 locations across the United States. We are a leading building and service provider for mechanical, electrical, and plumbing building systems. Our national footprint provides us the ability to meet your objectives to build and maintain safe, comfortable, and efficient facilities. Across the United States, companies turn to Comfort Systems USA for our unparalleled expertise in mechanical and electrical services, process piping, modular construction, controls, energy efficiency, and countless other nonresidential building renovation and service needs. We focus on a long-term approach by emphasizing safety and sustainability in everything we do. You can count on Comfort Systems USA to integrate planning, engineering, and implementation to provide you with a customized approach to all of your complex building needs. WE BUILD LEGACIES WITH OUR CUSTOMERS by safely installing and maintaining their most critical building systems PEOPLE by providing the tools and paths for individual career achievement ACQUISITIONS by preserving and advancing their life’s work OUR VALUES Be safe. Be honest. Be respectful. Be innovative. Be collaborative. Our values define, inform, and guide the way we operate on a daily basis, both within the company and in the communities where we do business.

Comfort Systems USA, Inc.

675 Bering Drive, Suite 400

Houston, Texas 77057

Message from

our Chair and CEO

Franklin Myers IBrian E. Lane IApril 7, 2025

To our Stockholders:

You are cordially invited to attend the Annual Meeting of the Stockholders of Comfort Systems USA, Inc., which will be held on Friday, May 16, 2025 at 11:00 a.m. Central Time.

Information about the meeting is presented on the following pages. At this meeting, you are being asked to elect the ten directors nominated by the board to serve until the next annual meeting; to ratify the appointment of Deloitte & Touche LLP, independent auditors, as the Company’s auditors for 2025; and to approve, by stockholder non-binding advisory vote, the compensation paid by the Company to its named executive officers, commonly referred to as a “Say on Pay” proposal.

Please read the proxy statement, which presents important information about the Company and each of the items being presented for stockholder vote. Whether or not you intend to be present in person, when you have finished reading the statement, please submit your vote promptly by telephone or internet, which saves the Company money, or by marking, signing, and returning your proxy card in the enclosed envelope so that your shares will be represented.

We hope that many of you will be able to attend the meeting in person. We look forward to seeing you there.

Sincerely yours,

April 7, 2025

NOTICE IS HEREBY GIVEN that the 2025 Annual Meeting of Stockholders (the “Annual Meeting”) of Comfort Systems USA, Inc., a Delaware corporation (the “Company”), will be held:

Friday, May 16, 2025 11:00 a.m. Central Time

The St. Regis Houston 1919 Briar Oaks Lane Houston, Texas 77027

Stockholders of record at the close of business on March 17, 2025 are entitled to notice of, and to vote at, the Annual Meeting.

By Order of the Board of Directors,

Laura Howell

Corporate Secretary

Houston, Texas

April 7, 2025

ITEMS OF BUSINESS

We are not aware of any other business to come before the Annual Meeting. Any action may be taken on any one of the foregoing proposals at the Annual Meeting on the date specified above, or on any date or dates to which the Annual Meeting may be adjourned or postponed. Stockholders of record at the close of business on March 17, 2025 are entitled to notice of, and to vote at, the Annual Meeting. In the event that there are not enough votes for a quorum or to approve or ratify any of the foregoing proposals at the time of the Annual Meeting, the Annual Meeting may be adjourned or postponed in order to permit our further solicitation of proxies.

TO ASSURE YOUR REPRESENTATION AT THE MEETING, PLEASE EITHER FOLLOW THE DIRECTIONS FOR PHONE OR INTERNET VOTING ON YOUR PROXY CARD OR SIGN, DATE, AND RETURN YOUR PROXY AS PROMPTLY AS POSSIBLE. AN ENVELOPE, WHICH REQUIRES NO POSTAGE IF MAILED IN THE UNITED STATES, IS ENCLOSED FOR THIS PURPOSE.