On November 3, 2026, Pinnacle West Capital Corporation (“Pinnacle West”) issued a press release regarding its financial results for the fiscal quarter ended September 30, 2026. A copy of the press release is attached hereto as Exhibit 99.1.

On August 4, 2026, Pinnacle West Capital Corporation (“Pinnacle West”) issued a press release regarding its financial results for the fiscal quarter ended June 30, 2026. A copy of the press release is attached hereto as Exhibit 99.1.

Entry into a Material Definitive Agreement. On August 4, 2026, Pinnacle West Capital Corporation (the “Company”) entered into an Equity Distribution Agreement (the “Equity Distribution Agreement”) with BMO Capital Markets Corp., BTIG, LLC, Citigroup Global Markets Inc., Morgan Stanley & Co. LLC, RBC Capital Markets, LLC, Scotia Capital (USA) Inc., TD Securities (USA) LLC and Truist Securities, Inc., as managers (each, a “Manager” and, collectively, the “Managers”), Bank of Montreal, Citibank,…

Executive Vice President and Chief Nuclear Officer — Adam Heflin: Compensatory arrangement for a named executive officer.

Other Events. On June 5, 2026, Pinnacle West Capital Corporation (the “Company”) entered into the First Amendment (the “First Amendment”) to the Equity Distribution Agreement, dated November 8, 2024 (as amended by the First Amendment, the “Equity Distribution Agreement”) with Barclays Capital Inc., BofA Securities, Inc., J.P. Morgan Securities LLC, Mizuho Securities USA LLC, MUFG Securities Americas Inc., TD Securities (USA) LLC, Truist Securities, Inc. and Wells Fargo Securities, LLC, as man…

On May 4, 2026, Pinnacle West Capital Corporation (“Pinnacle West”) issued a press release regarding its financial results for the fiscal quarter ended March 31, 2026. A copy of the press release is attached hereto as Exhibit 99.1.

On February 25, 2026, Pinnacle West Capital Corporation (the “Company” or “Pinnacle West”) issued a press release regarding its financial results for the fiscal quarter and full year ended December 31, 2025 and its earnings outlook for 2026. A copy of the press release is attached hereto as Exhibit 99.1.

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information set forth under

The filing describes the approval of incentive award opportunities for certain officers under the APS Plan and Palo Verde Plan.

Entry into a Material Definitive Agreement. Pinnacle West Capital Corporation’s (“Pinnacle West”) T hird Amended and Restated Facility On February 18, 2026, Pinnacle West entered into a third amended and restated five-year unsecured revolving credit facility (the “Third Amended and Restated Facility”) among Pinnacle West, the Lenders party thereto, Barclays Bank PLC, as Agent and Issuing Bank, PNC Bank, National Association, as Co-Syndication Agent and Issuing Bank, Wells Fargo Bank, National…

On November 3, 2025, Pinnacle West Capital Corporation (“Pinnacle West”) issued a press release regarding its financial results for the fiscal quarter ended September 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1.

Entry into a Material Definitive Agreement On August 28, 2025, Pinnacle West Capital Corporation (the “Company”) entered into an amendment (the “Amendment”) to the forward sale agreements (the “Forward Sale Agreements”), dated as of February 28, 2024 and February 29, 2024, respectively, between the Company and Wells Fargo Bank, National Association. The Amendment provides for a December 31, 2026 settlement date for the Share Forward Transactions (as defined in the Amendment), subject to the t…

On August 6, 2025, Pinnacle West Capital Corporation (“Pinnacle West”) issued a press release regarding its financial results for the fiscal quarter ended June 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1.

On May 1, 2025, Pinnacle West Capital Corporation (“Pinnacle West”) issued a press release regarding its financial results for the fiscal quarter ended March 31, 2025. A copy of the press release is attached hereto as Exhibit 99.1.

On February 25, 2025, Pinnacle West Capital Corporation (the “Company” or “Pinnacle West”) issued a press release regarding its financial results for the fiscal quarter and full year ended December 31, 2024 and its earnings outlook for 2025. A copy of the press release is attached hereto as Exhibit 99.1.

Chief Legal Officer — Robert E. Smith: The filing announces a planned retirement of the Chief Legal Officer with a named internal successor, indicating an orderly succession rather than a sudden loss of executive talent.

CEO — Jeffrey B. Guldner: The filing details the approval of annual incentive award plans for existing executives, which is a compensatory arrangement rather than a change in management personnel.

CEO — Jeffrey B. Guldner: The CEO is retiring with a pre-announced, named internal successor (Theodore N. Geisler) and a transition plan, indicating an orderly succession rather than a sudden loss of leadership.

Entry into a Material Definitive Agreement. On November 8, 2024, Pinnacle West Capital Corporation (the “Company”) entered into an Equity Distribution Agreement (the “Equity Distribution Agreement”) with BofA Securities, Inc., Barclays Capital Inc., J.P. Morgan Securities LLC, Mizuho Securities USA LLC, MUFG Securities Americas Inc., TD Securities (USA) LLC, Truist Securities, Inc. and Wells Fargo Securities, LLC, as managers (each, a “Manager” and, collectively, the “Managers”), Bank of Amer…

Entry into a Material Definitive Agreement. On November 8, 2024, Pinnacle West Capital Corporation (the “Company”) entered into an Equity Distribution Agreement (the “Equity Distribution Agreement”) with BofA Securities, Inc., Barclays Capital Inc., J.P. Morgan Securities LLC, Mizuho Securities USA LLC, MUFG Securities Americas Inc., TD Securities (USA) LLC, Truist Securities, Inc. and Wells Fargo Securities, LLC, as managers (each, a “Manager” and, collectively, the “Managers”), Bank of Amer…

On November 6, 2024, Pinnacle West Capital Corporation (“Pinnacle West”) issued a press release regarding its financial results for the fiscal quarter ended September 30, 2024. A copy of the press release is attached hereto as Exhibit 99.1.

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information set forth above in

Entry into a Material Definitive Agreement. First Amendment to the Pinnacle West Capital Corporation (“Pinnacle West”) Facility On August 2, 2024, Pinnacle West entered into the Amendment No. 1 (the “Pinnacle West First Amendment”) to its five-year unsecured revolving credit facility (the “Pinnacle West Facility”), dated April 10, 2023, with Barclays Bank PLC, as Agent, Co-Sustainability Structuring Agent and Issuing Bank, Mizuho Bank, Ltd., as Co-Syndication Agent, Co-Sustainability Structur…

On August 1, 2024, Pinnacle West Capital Corporation (“Pinnacle West”) issued a press release regarding its financial results for the fiscal quarter ended June 30, 2024. A copy of the press release is attached hereto as Exhibit 99.1.

Director — Carol S. Eicher, Susan T. Flanagan, Ronald Butler, Jr.: The filing discloses the routine expansion of the board and the election of three new directors, which is a standard governance event rather than a departure or executive change.