QUANTA SERVICES, 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. )

CHECK THE APPROPRIATE BOX:

Quanta Services, Inc.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if Other Than the Registrant)

PAYMENT OF FILING FEE (CHECK THE APPROPRIATE BOX):

Quanta 2026 PROXY STATEMENT

NOTICE OF ANNUAL MEETING

OF STOCKHOLDERS

Quanta Services, Inc.

2727 North Loop West

Houston, TX 77008 | (713)629-7600

TO BE HELD MAY 21, 2026

To our Stockholders:

The annual meeting of stockholders of Quanta Services, Inc. (“Quanta”) will be held at the company’s corporate headquarters, located at 2727 North Loop West, Houston, Texas 77008, on May 21, 2026, at 8:30 a.m. local time. At the meeting, you will be asked to consider and act upon the following matters, which are more fully described in the accompanying Proxy Statement:

Our stockholders of record at the close of business on April 2, 2026, are entitled to notice of, and to vote at, the annual meeting and any adjournments or postponements of the meeting.

By Order of the Board of Directors,

Matthew D. McCoy

Corporate Secretary

Houston, Texas

April 10, 2026

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE ANNUAL MEETING OF STOCKHOLDERS TO BE HELD ON MAY 21, 2026:

The Notice, Proxy Statement and 2025 Annual Report to Stockholders are available atwww.proxydocs.com/PWR.

This summary highlights selected information about the items to be voted on at the 2026 annual meeting of stockholders (the “Annual Meeting”) of Quanta Services, Inc. (together with its subsidiaries, “Quanta” or the “Company”). This summary does not contain all of the information that you should consider in deciding how to vote. You should read the entire Proxy Statement carefully before voting.

2026 Annual Meeting of Stockholders

Where The Company’s corporate headquarters, located at 2727 North Loop West, Houston, Texas 77008

When May 21, 2026, at 8:30 a.m. local time

Record Date Our stockholders of record at the close of business on April 2, 2026, are entitled to notice of, and to vote at, the Annual Meeting and any adjournments or postponements of the meeting.

Annual Meeting Agenda and

Voting Recommendations

Stockholders are being asked to vote on three agenda matters:

Voting Your Shares

Your vote is important. Even if you plan to attend the Annual Meeting in person, the Board of Directors of Quanta (the “Board”) recommends that you cast your vote as soon as possible. Stockholders of record may vote by any of the below methods.

i

Proposal 1: Election of Directors

The Board of Directors unanimously recommends a vote FOR the election of each of the director nominees. u See page 1 for further information

Director Nominees

The table below provides summary information about each director nominee. Each director nominee is elected annually by a majority of votes cast.

ii

Snapshot of 2026 Director Nominees

Board Qualifications, Skills and Experience

The Board regularly reviews the desired qualifications, skills and experiences that it believes are appropriate to oversee Quanta’s business and long-term strategy. Attributes brought by director nominees include:

Corporate Governance Highlights

We are committed to strong governance standards, as evidenced by the key best practices below.

✓ Annual election of directors

✓ Majority voting standard for election of directors in uncontested elections

✓ Director resignation policy

✓ Holders of Quanta common stock vote as a single class on all matters

✓ Separate Independent Chairman of the Board and Chief Executive Officer

✓ Annual stockholder engagement

✓ Robust stock ownership requirements for directors and officers

iii

✓ Meaningful annual limit onnon-employee director compensation

✓ Code of Conduct that applies to all directors, officers and employees

✓ Robust oversight process of business strategy, risk management and corporate sustainability and responsibility matters

✓ Commitment to Board refreshment and composition aligned with the strategic direction of the Company

Proposal 2: Advisory Vote to Approve Named Executive Officer Compensation

The Board of Directors unanimously recommends a vote FOR the advisory resolution approving the compensation of Quanta’s named executive officers for fiscal year 2025. u See page 31 for further information

Compensation Overview

During 2025, Quanta continued to utilize its innovative approach to its infrastructure solutions, combined with the strength of its portfolio of services, to perform at a high level and produce superior operational and financial results. Quanta achieved many strategic, operational and financial accomplishments throughout the Company. The Company achieved many record financial results, including record annual revenues, net income attributable to common stock, adjusted EBITDA and earnings per share, as well as record net cash provided by operating activities and free cash flow. Quanta also ended 2025 with record remaining performance obligations and backlog, exemplifying the accelerating demand across the Company’s markets and positioning the Company well for 2026.

Quanta continued to develop and expand key service offerings and enhance the Company’s position as a total solutions provider for its customers as they continue to execute significant capital budgets in response to overall load growth, which is being driven by technology advancements and grid resilience and security initiatives. In furtherance of these strategic initiatives, during 2025 Quanta completed eight acquisitions that augmented its existing solutions offerings, including with respect to mechanical infrastructure solutions, civil solutions and aviation services, as well as a strategic supply chain investment in a company that specializes in harvesting, treating and manufacturing wood poles for the utility and telecommunication industries. Of note, Quanta completed the strategic acquisition of Dynamic Systems (DSI), LLC, a provider of turnkey mechanical, plumbing and process infrastructure solutions to a diversified customer base that includes technology, semiconductor, healthcare and other load center markets, which provides Quanta with a mechanical solutions platform that expands and diversifies its customer base and enhances its ability to provide cost- and labor-certain infrastructure solutions at scale. Quanta believes its consistent performance and these accomplishments are indicative of the strength of its solutions-based strategy and remains focused on delivering superior financial performance and returning value to its stockholders. Quanta also remains focused on continuing its commitments to all stakeholders of the Company, including the safety and training of its workforce and responsible performance within communities in which it operates.

With respect to performance under the Company’s 2025 annual incentive plan, the overall achievement percentage was 126.8% of target performance, which was driven by significant year-over-year improvement and above-target performance with respect to the earnings- and margin-based performance metrics, partially offset by performance slightly below target with respect to the safety performance improvement metric. Quanta also completed an exceptional 2023-2025 performance cycle that resulted in an achievement percentage of 188.5% of target performance under the 2023 long-term incentive plan, driven by continued improvement in the utilization of capital. Additionally, the financial performance targets and metrics included in the Company’s 2025 annual and long-term incentive plans continue to generally represent improvement over historical performance and prior targets and support Quanta’s strategic initiatives with respect to increased earnings and improvement in return on invested capital.

iv

2025 Target Compensation Mix

Quanta’s named executive officer (“NEO”) compensation is primarily comprised of base salary, short-term cash incentives and long-term equity incentives. Target award levels generally reflect competitive market levels and practices, with upside opportunity for performance above target levels, and performance measures are chosen to align the interests of executives with stockholders.

2025 Long-Term Incentive Plan Equity Mix

A significant portion of equity-based incentive awards (70% with respect to the Chief Executive Officer (“CEO”) and President of Electric Power and 60% with respect to other NEOs) is tied to measurable Company performance over a 3-year performance period.

v

Elements of Executive Compensation

vi

Compensation Governance

We are committed to strong governance standards that ensure our executive compensation program is closely aligned with the interests of our stockholders and other stakeholders, as evidenced by the policies and practices described below.

What We Do

What We Don’t Do

Proposal 3: Ratification of the Appointment of Independent Registered Public Accounting Firm

The Board of Directors unanimously recommends a vote FOR ratification of the appointment of PricewaterhouseCoopers LLP as Quanta’s independent registered public accounting firm for fiscal year 2026. u See page 75 for further information

vii

TABLE OF

CONTENTS

Board Recommendation✓X