PINNACLE WEST CAPITAL CORP

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

SCHEDULE 14A

PROXY STATEMENT PURSUANT TO SECTION 14(a)

OF THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. )

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A Message from Our Chairman, President and CEO

A Message to Our Shareholders:On behalf of our Board of Directors, management, and employees, I invite you to participate in our 2025 Annual Meeting of Shareholders. The meeting will be held at 1:30 p.m. (EDT), Wednesday, May 21, 2025. Details regarding how to attend the meeting and the business to be conducted are in the accompanying Notice of Annual Meeting and Proxy Statement.

Leadership Transition

I am honored and humbled by the trust placed in me by our Board of Directors to serve as the next leader of Pinnacle West and APS. As a third-generation Arizonan, I am intimately familiar with our Company’s essential role in powering the progress of this flourishing state. I began my career at APS 24 years ago and have served in a variety of roles across our enterprise, which has equipped me with a familiarity and appreciation for the challenges and opportunities of our business. My commitment to our employees, shareholders, customers, and communities is unwavering.

My predecessor, Jeff Guldner, helped us create a strong foundation for the Company’s success with his collaborative and partnership-driven leadership approach over the past five years. Under his leadership, the team has achieved performance improvements across all aspects of our business, including improving APS's customers’ experience and the Company’s long-term financial health. We are truly grateful for Jeff’s 20 years of service overall to Pinnacle West and APS.

2024 Highlights

Jeff and I detail many of the Company’s 2024 accomplishments in our letter to shareholders in this year’s Annual Report, but allow me to share the following highlights that make us particularly proud:

•our dedicated, safety-focused employees achieved a milestone of zero serious injury and fatality incidents;

•our employees worked through 113 consecutive days of 100 degrees or higher in Phoenix, the longest stretch in Arizona history, to deliver top quartile reliability for APS's customers;

•the APS service territory continues to attract robust growth – we experienced 5.7% sales growth in kWhs of electricity sold and 2.1% customer growth. For the second consecutive year, APS's customers set a peak energy demand record;

•APS was named the top corporate philanthropist by the Phoenix Business Journal and partnered with more than 100 local non-profit and community agencies to connect Arizona’s most vulnerable populations with helpful resources year-round. Our employees had another strong year for hours volunteered serving our communities – an important part of our culture;

•we procured 7,300 MWs of new generation resources – including renewable energy, battery storage and natural gas to be online between 2026 and 2028 – more than 90% of which is expected to be carbon-free;

•for the 16th consecutive year – and 20th overall – Palo Verde Generating Station’s three nuclear units exceeded 30 million MWh of net generation and achieved a capacity factor of 93.7%;

•we achieved our highest collective rank and placements in J.D. Power customer satisfaction studies since 2016. APS climbed to the top of the second quartile among all large investor-owned utilities for both business and residential customers; and

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•Pinnacle West achieved year-end earnings of $5.24 per diluted share of common stock, above our initial expectations at the year’s onset, and we executed our largest capital expansion plan in APS's history.

You can be proud of what your Company accomplished in 2024.

Our Path Forward

The path forward consists of a corporate strategy that focuses on the need for grid expansion, timely recovery of our grid investments, continuing our emphasis on providing an outstanding customer experience, and a relentless focus on talent development. We continue to develop and implement our strategic plan to satisfy the needs of our customers, support Arizona’s impressive growth and economic activity, and create value for our shareholders.

The APS service territory has entered an era of unprecedented growth and demand on the system. In 2024, we installed more than 32,000 new residential meters, the most since the Great Recession. We are well-positioned to capitalize on this demand and have embarked on the largest transmission and generation expansion in APS's history, which is driving $9.65 billion in overall capital investments through 2027. We are committed to serving Arizona’s economic and population growth responsibly, while maintaining top tier reliability for our customers as we connect new large customer facilities like chip manufacturers and data centers. We continue to make progress on responsibly decarbonizing the electric grid while focusing on reliability and affordability for our customers. We are also working to improve timely investment recovery through innovative rate design and regulatory outcomes that benefit APS's customers and the Company.

Board of Directors Acknowledgement

Jeff and I want to thank the Board of Directors for their outstanding support in 2024. Our Board of Directors plays a vital role in establishing and overseeing our corporate strategy, and its members are very thoughtful and highly engaged in the Company. I look forward to working with the Board as we move Pinnacle West and APS into the future. I especially want to acknowledge Bruce Nordstrom, who will retire from the Board this year. We will miss his thoughtful approach and engagement with our team, and we thank him for his decades of service to the Company.

Thank You to Our Investors

Finally, your vote is important to us. Whether or not you plan to participate in the Annual Meeting of Shareholders, we encourage you to vote promptly. You may vote on: the internet; by telephone; or by completing, signing, dating, and returning a Proxy Card or Voting Instruction Form.

We thank you for your investment and continued support of Pinnacle West.

Sincerely,

Theodore N. Geisler

Chairman of the Board, President

and Chief Executive Officer

A Message from Our Independent Directors

Dear Fellow Shareholders,

As Independent Directors, we are committed to sound governance principles and are focused on ensuring long term value for our shareholders. As Pinnacle West makes progress toward improving shareholder returns, we are concentrating on management succession, improving customer satisfaction, ensuring reliability and maintaining affordability as we decarbonize in a responsible manner. We are honored and proud to serve as your Board of Directors. Below are a few highlights of our activities during 2024:

CEO Succession

At the end of 2024, we appointed Ted Geisler as Chairman of the Board, Chief Executive Officer and President of Pinnacle West and Chairman of the Board and Chief Executive Officer of APS, effective April 1, 2025. We have watched Ted grow over the years and continue to be impressed with his business acumen and his leadership skills. He is focused on doing what is right for our shareholders, customers and Arizona. We look forward to supporting Ted as he leads the Company forward. Sadly, we will be saying farewell to an exceptional CEO, Jeff Guldner. During the last five years in this role, the Company launched the APS Promise, implemented our 10-Year Strategic Plan, which focused on building relationships with key stakeholders and improving our reputation with customers and regulators, and presented our Clean Energy Commitment. He did all of this while navigating a worldwide pandemic that required our employees to adjust where, when and how they worked.

Board Succession

In June of 2024, we announced the addition of three new directors, Ron Butler, Jr., Carol Eicher and Susan Flanagan, with the appointments effective July 1, 2024. All three were outstanding candidates and although it can be a challenge to add three new board members at once, we felt they would be valuable additions to the Board and we didn’t want to wait. All three new directors bring their own individual skill set to the Board: Ron brings extensive audit experience and an Arizona presence, Carol brings public company board service and large company operating experience, and Susan brings a depth of financial and industry experience. You can read more about our new directors in the Proxy Statement.

This year we will say goodbye to Bruce Nordstrom. Bruce has been an extremely valued member of the Board and will be greatly missed. Among other things, Bruce has represented our APS customers in Northern Arizona and served as Chairman of the Audit Committee of the Board. His counsel and thoughtful leadership have helped shape the Company and your Board. We anticipate that Ron Butler will assume the Chair of the Audit Committee.

Rick Fox, who currently serves as the Chairman of the Human Resources Committee and is a member of the Audit Committee, was set to retire this year as well. However, the Board took a hard look at the upcoming changes facing the Board and has asked Rick to remain with us for an additional year to assist in the transition of the leadership of the Audit Committee and the Human Resources Committee. As a former Audit Committee Chairman at other companies and as the Company's current Chair of the Human Resources Committee, we believe he has the skills needed to assist with this transition. Under the Director Retirement Policy, the Board has the authority to extend the age limit for a particular nominee in those circumstances where the Board believes it is in the best interests of the Company. We do not take making the decision to extend the limit lightly, but we believe that in this situation it is in the best interests of the Board and the Company to allow Rick Fox to remain on the Board for one more year. We anticipate that Bill Spence will assume the chair of the Human Resources Committee.

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Oversight of Strategy

The energy industry continues to change rapidly. The energy landscape in Arizona is experiencing unprecedented load growth and increases in demand for energy, fueled in part by data centers and hyperscalers. At our Board meetings and during our Strategic Retreat, we engage with the management team in robust discussions about overall strategy, business priorities, long-term risks, and growth opportunities while focusing on shareholder returns, customer experience and satisfaction, system reliability, resiliency, and affordability.

Risk and Risk Management

Risk, and risk management, are issues that the Board reviews on a regular basis. As you will note on page 23 of the Proxy Statement, the Board engages in detailed risk review discussions with the management team, as well as the employee subject matter experts when appropriate. In 2024, we also engaged in a thorough and comprehensive review of the risks identified in this Proxy Statement and other risks identified by the Company as its top risks, noting in particular, that wildfire, cybersecurity and resource adequacy risks have been, and will continue to be, areas of focus for the Board. We understand that a critical role of the Board is risk oversight; be assured it is a priority for the Board and one that we actively address.

Shareholder Outreach

What our investors think is very important to us. We support management’s efforts to engage with a broad set of stakeholders throughout the year, and the independent directors have had the opportunity to engage with our investors as well. We appreciate your perspectives, and we review your comments and feedback and incorporate them into our decision making.

Thank you for the trust you place in us. The Board is engaged and committed to our common goal of creating enduring, long-term value for customers, employees, and shareholders alike.

Sincerely,