PNW / Pinnacle West Capital Corporation - SEC-Einreichungen, Jahresbericht, Proxy Statement

Security Type

Calculation of Filing Fee Tables S-3 PINNACLE WEST CAPITAL CORP Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Debt 4.

PROSPECTUS SUPPLEMENT (To Prospectus Dated February 28, 2024) Pinnacle West Capital Corporation 4.650% Senior Notes due 2029

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(5)   Registration No. 333-277448 PROSPECTUS SUPPLEMENT (To Prospectus Dated February 28, 2024) $500,000,000 Pinnacle West Capital Corporation 4.650% Senior Notes due 2029 This is an offering by Pinnacle West Capital Corporation of $500,000,000 of its 4.650% Senior Notes due 2029, referred to in this prospectus supplement as the “notes.” Interest on

SUBJECT TO COMPLETION, DATED JUNE 1, 2026 PRELIMINARY PROSPECTUS SUPPLEMENT (To Prospectus Dated February 28, 2024) Pinnacle West Capital Corporation     % Senior Notes due 20

TABLE OF CONTENTS The information in this preliminary prospectus supplement is not complete and may be changed.

Final Term Sheet Pinnacle West Capital Corporation $500,000,000 4.650% Senior Notes due 2029 June 1, 2026

Filed under Rule 433 File No. 333-277448 Final Term Sheet Pinnacle West Capital Corporation $500,000,000 4.650% Senior Notes due 2029 June 1, 2026 Issuer: Pinnacle West Capital Corporation Expected Ratings (Moody’s / S&P / Fitch): Baa2 (stable) / BBB (stable) / BBB (stable) Note: A securities rating is not a recommendation to buy, sell or hold securities and may be subject to revision or withdrawa

As filed with the Securities and Exchange Commission on May 29, 2026

As filed with the Securities and Exchange Commission on May 29, 2026 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 14, 2026 Commission File Number

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 14, 2026 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Powering Arizona’s Future May Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking stateme

mayinvestordeck Powering Arizona’s Future May Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 6, 2026 Commission File Number

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 6, 2026 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Registrant's telephone Number, Including Area Code) IRS Employer Identification No.

Powering Arizona’s Future May Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking stateme

mayinvestordeck Powering Arizona’s Future May Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 6, 2026 Commission File Number

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 6, 2026 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Registrant's telephone Number, Including Area Code) IRS Employer Identification No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 4, 2026 Commission File Numbe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 4, 2026 Commission File Number Exact name of registrant as specified in its charter; State or other jurisdiction of incorporation or organization; Address of principal executive o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 4, 2026 Commission File Numbe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 4, 2026 Commission File Number Exact name of registrant as specified in its charter; State or other jurisdiction of incorporation or organization; Address of principal executive o

PINNACLE WEST REPORTS 2026 FIRST-QUARTER FINANCIAL RESULTS

Exhibit 99.1 FOR IMMEDIATE RELEASE May 4, 2025 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Website: pinnaclewest.com PINNACLE WEST REPORTS 2026 FIRST-QUARTER FINANCIAL RESULTS •Hotter-than-normal weather drives increase in customer sales and usage •Customer growth of 2.2% continues to underscore a strong Arizona economy •APS employees focus on critical summ

PINNACLE WEST REPORTS 2026 FIRST-QUARTER FINANCIAL RESULTS

Exhibit 99.1 FOR IMMEDIATE RELEASE May 4, 2025 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Website: pinnaclewest.com PINNACLE WEST REPORTS 2026 FIRST-QUARTER FINANCIAL RESULTS •Hotter-than-normal weather drives increase in customer sales and usage •Customer growth of 2.2% continues to underscore a strong Arizona economy •APS employees focus on critical summ

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact name of regist

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact name of regist

Powering Arizona’s Future First-Quarter Financial Results May 4, 2026 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These f

q12026xearningsxfinal Powering Arizona’s Future First-Quarter Financial Results May 4, 2026 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Powering Arizona’s Future First-Quarter Financial Results May 4, 2026 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These f

q12026xearningsxfinal Powering Arizona’s Future First-Quarter Financial Results May 4, 2026 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 15, 2026 Commission File Numb

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 15, 2026 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Registrant's telephone Number, Including Area Code) IRS Employer Identification No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 15, 2026 Commission File Numb

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 15, 2026 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Registrant's telephone Number, Including Area Code) IRS Employer Identification No.

Powering Arizona’s Future April Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking state

aprilinvestordeck Powering Arizona’s Future April Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Powering Arizona’s Future April Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking state

aprilinvestordeck Powering Arizona’s Future April Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

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. )

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.

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. )

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.

As filed with the Securities and Exchange Commission on March 25, 2026

As filed with the Securities and Exchange Commission on March 25, 2026 Registration No.

ARIZONA PUBLIC SERVICE COMPANY THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. As Trustee under Arizona Public Service Company’s Indenture dated as of January 15, 1998 Thirty-Third Supplemental Indenture Dated as of March 12, 2026 5.10% Notes due 203

Exhibit 4.1 ARIZONA PUBLIC SERVICE COMPANY TO THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. As Trustee under Arizona Public Service Company’s Indenture dated as of January 15, 1998 Thirty-Third Supplemental Indenture Dated as of March 12, 2026 5.10% Notes due 2036 This THIRTY-THIRD SUPPLEMENTAL INDENTURE, dated as of March 12, 2026, is between Arizona Public Service Company, a corporation duly o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 10, 2026 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

ARIZONA PUBLIC SERVICE COMPANY $600,000,000 5.10% Notes due 2036 UNDERWRITING AGREEMENT

Exhibit 1.1 ARIZONA PUBLIC SERVICE COMPANY $600,000,000 5.10% Notes due 2036 UNDERWRITING AGREEMENT March 10, 2026 BofA Securities, Inc. One Bryant Park New York, New York 10036 J.P. Morgan Securities LLC 270 Park Avenue New York, New York 10017 Mizuho Securities USA LLC 1271 Avenue of the Americas New York, New York 10020 RBC Capital Markets, LLC Brookfield Place 200 Vesey Street, 8th Floor New Y

ARIZONA PUBLIC SERVICE COMPANY THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. As Trustee under Arizona Public Service Company’s Indenture dated as of January 15, 1998 Thirty-Third Supplemental Indenture Dated as of March 12, 2026 5.10% Notes due 203

Exhibit 4.1 ARIZONA PUBLIC SERVICE COMPANY TO THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. As Trustee under Arizona Public Service Company’s Indenture dated as of January 15, 1998 Thirty-Third Supplemental Indenture Dated as of March 12, 2026 5.10% Notes due 2036 This THIRTY-THIRD SUPPLEMENTAL INDENTURE, dated as of March 12, 2026, is between Arizona Public Service Company, a corporation duly o

ARIZONA PUBLIC SERVICE COMPANY $600,000,000 5.10% Notes due 2036 UNDERWRITING AGREEMENT

Exhibit 1.1 ARIZONA PUBLIC SERVICE COMPANY $600,000,000 5.10% Notes due 2036 UNDERWRITING AGREEMENT March 10, 2026 BofA Securities, Inc. One Bryant Park New York, New York 10036 J.P. Morgan Securities LLC 270 Park Avenue New York, New York 10017 Mizuho Securities USA LLC 1271 Avenue of the Americas New York, New York 10020 RBC Capital Markets, LLC Brookfield Place 200 Vesey Street, 8th Floor New Y

ARIZONA PUBLIC SERVICE COMPANY 5.10% Note due 2036

Exhibit 4.2 UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO ARIZONA PUBLIC SERVICE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAY

Item 14. Other Expenses of Issuance and Distribution.

Exhibit 99.1 Item 14. Other Expenses of Issuance and Distribution. The expenses, other than underwriting discounts and commissions, to be incurred by Arizona Public Service Company (“APS”) relating to the offering of $600,000,000 principal amount of its 5.10% Notes due 2036, under APS’s Registration Statement on Form S-3 (No. 333-277448-01) and a related prospectus supplement filed with the Securi

ARIZONA PUBLIC SERVICE COMPANY 5.10% Note due 2036

Exhibit 4.2 UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO ARIZONA PUBLIC SERVICE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAY

Item 14. Other Expenses of Issuance and Distribution.

Exhibit 99.1 Item 14. Other Expenses of Issuance and Distribution. The expenses, other than underwriting discounts and commissions, to be incurred by Arizona Public Service Company (“APS”) relating to the offering of $600,000,000 principal amount of its 5.10% Notes due 2036, under APS’s Registration Statement on Form S-3 (No. 333-277448-01) and a related prospectus supplement filed with the Securi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 10, 2026 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 27, 2026 Commission File N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 27, 2026 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Registrant's telephone Number, Including Area Code) IRS Employer Identification No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 27, 2026 Commission File N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 27, 2026 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Registrant's telephone Number, Including Area Code) IRS Employer Identification No.

Powering Arizona’s Future March Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking state

a2026marchinvestordeck Powering Arizona’s Future March Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Powering Arizona’s Future March Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking state

a2026marchinvestordeck Powering Arizona’s Future March Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

DESCRIPTION OF THE REGISTRANTS’ SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 Pinnacle West Capital Corporation (“Pinnacle West”)

Exhibit 4.5 DESCRIPTION OF THE REGISTRANTS’ SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 Pinnacle West Capital Corporation (“Pinnacle West”) The following description of Pinnacle West’s securities registered pursuant to Section 12 of the Securities Exchange Act of 1934 is a summary and does not purport to be complete. The description is subject to, and qualif

ARS

PINNACLE WEST CAPITAL CORPORATION 2025 ANNUAL REPORT 0% 2% 4% 6% 8% ’21 ’22 ’23 ’24 ’25 Through ’30 Projected Range Sales Growth Customer Growth 1.

FORM OF RESTRICTED STOCK UNIT AWARD AGREEMENT

Exhibit 10.10(g) FORM OF RESTRICTED STOCK UNIT AWARD AGREEMENT THIS AWARD AGREEMENT is made and entered into as of ###GRANTDATE### (the “Date of Grant"), by and between Pinnacle West Capital Corporation (the "Company") and ###PARTICIPANTNAME### ("Employee"). BACKGROUND A.The Board of Directors of the Company (the “Board of Directors”) has adopted, and the shareholders of the Company have approved,

Powering Arizona’s Future Fourth-Quarter and Full-Year 2025 Financial Results February 25, 2026 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial

q42025xearningsxfinal Powering Arizona’s Future Fourth-Quarter and Full-Year 2025 Financial Results February 25, 2026 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

PINNACLE WEST REPORTS 2025 FULL-YEAR AND FOURTH-QUARTER RESULTS

Exhibit 99.1 FOR IMMEDIATE RELEASE February 25, 2026 Media Contact: Alan Bunnell (602) 250-3376 Analyst Contacts: Amanda Ho (602) 250-3334 Website: pinnaclewest.com PINNACLE WEST REPORTS 2025 FULL-YEAR AND FOURTH-QUARTER RESULTS •Full-year financial results positively impacted by robust customer and sales growth •Operating performance, customer reliability remain strong •Company continues prioriti

FORM OF PERFORMANCE SHARE AWARD AGREEMENT

Exhibit 10.10(h) FORM OF PERFORMANCE SHARE AWARD AGREEMENT THIS AWARD AGREEMENT is made and entered into as of ###GRANTDATE### (the “Date of Grant”), by and between Pinnacle West Capital Corporation (the “Company”), and ###PARTICIPANTNAME### (“Employee”). BACKGROUND A.The Board of Directors of the Company (the “Board of Directors”) has adopted, and the Company’s shareholders have approved, the Pin

AMENDMENT TO AMENDMENT NO. 13 TO FOUR CORNERS PROJECT CO-TENANCY AGREEMENT

Exhibit 10.15(a) AMENDMENT TO AMENDMENT NO. 13 TO FOUR CORNERS PROJECT CO-TENANCY AGREEMENT This Amendment to Amendment No. 13 to the Four Corners Project Co-Tenancy Agreement (this “Amendment”) is dated as July 1. 2024 (the “Effective Date”), and entered into by and between Arizona Public Service Company, an Arizona corporation (“Arizona”), Public Service Company of New Mexico, a New Mexico corpo

Powering Arizona’s Future Fourth-Quarter and Full-Year 2025 Financial Results February 25, 2026 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial

q42025xearningsxfinal Powering Arizona’s Future Fourth-Quarter and Full-Year 2025 Financial Results February 25, 2026 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

FORM OF PERFORMANCE SHARE AWARD AGREEMENT

Exhibit 10.10(h) FORM OF PERFORMANCE SHARE AWARD AGREEMENT THIS AWARD AGREEMENT is made and entered into as of ###GRANTDATE### (the “Date of Grant”), by and between Pinnacle West Capital Corporation (the “Company”), and ###PARTICIPANTNAME### (“Employee”). BACKGROUND A.The Board of Directors of the Company (the “Board of Directors”) has adopted, and the Company’s shareholders have approved, the Pin

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact name of registrant

Summary of 2026 Incentive Plans

Exhibit 10.11 Summary of 2026 Incentive Plans On February 17, 2026, the Human Resources Committee (the “Committee”) of the Pinnacle West Capital Corporation (“Pinnacle West”) Board of Directors (the “Board”) approved the portion of the Arizona Public Service Company (“APS”) 2026 Annual Incentive Award Plan (the “APS Plan”) that provides an incentive award opportunity for Theodore N. Geisler, Chair

AMENDMENT TO AMENDMENT NO. 13 TO FOUR CORNERS PROJECT CO-TENANCY AGREEMENT

Exhibit 10.15(a) AMENDMENT TO AMENDMENT NO. 13 TO FOUR CORNERS PROJECT CO-TENANCY AGREEMENT This Amendment to Amendment No. 13 to the Four Corners Project Co-Tenancy Agreement (this “Amendment”) is dated as July 1. 2024 (the “Effective Date”), and entered into by and between Arizona Public Service Company, an Arizona corporation (“Arizona”), Public Service Company of New Mexico, a New Mexico corpo

FORM OF RESTRICTED STOCK UNIT AWARD AGREEMENT

Exhibit 10.10(g) FORM OF RESTRICTED STOCK UNIT AWARD AGREEMENT THIS AWARD AGREEMENT is made and entered into as of ###GRANTDATE### (the “Date of Grant"), by and between Pinnacle West Capital Corporation (the "Company") and ###PARTICIPANTNAME### ("Employee"). BACKGROUND A.The Board of Directors of the Company (the “Board of Directors”) has adopted, and the shareholders of the Company have approved,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 25, 2026 Commission File N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 25, 2026 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Summary of 2026 Incentive Plans

Exhibit 10.11 Summary of 2026 Incentive Plans On February 17, 2026, the Human Resources Committee (the “Committee”) of the Pinnacle West Capital Corporation (“Pinnacle West”) Board of Directors (the “Board”) approved the portion of the Arizona Public Service Company (“APS”) 2026 Annual Incentive Award Plan (the “APS Plan”) that provides an incentive award opportunity for Theodore N. Geisler, Chair

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact name of registrant

PINNACLE WEST REPORTS 2025 FULL-YEAR AND FOURTH-QUARTER RESULTS

Exhibit 99.1 FOR IMMEDIATE RELEASE February 25, 2026 Media Contact: Alan Bunnell (602) 250-3376 Analyst Contacts: Amanda Ho (602) 250-3334 Website: pinnaclewest.com PINNACLE WEST REPORTS 2025 FULL-YEAR AND FOURTH-QUARTER RESULTS •Full-year financial results positively impacted by robust customer and sales growth •Operating performance, customer reliability remain strong •Company continues prioriti

DESCRIPTION OF THE REGISTRANTS’ SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 Pinnacle West Capital Corporation (“Pinnacle West”)

Exhibit 4.5 DESCRIPTION OF THE REGISTRANTS’ SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 Pinnacle West Capital Corporation (“Pinnacle West”) The following description of Pinnacle West’s securities registered pursuant to Section 12 of the Securities Exchange Act of 1934 is a summary and does not purport to be complete. The description is subject to, and qualif

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 25, 2026 Commission File N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 25, 2026 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 17, 2026 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

U.S. $300,000,000 THIRD AMENDED AND RESTATED FIVE-YEAR CREDIT AGREEMENT Dated as of February 18, 2026 PINNACLE WEST CAPITAL CORPORATION, as Borrower, THE LENDERS PARTY HERETO, BARCLAYS BANK PLC, as Agent and Issuing Bank, PNC BANK, NATIONAL ASSOCIATI

Exhibit 10.1 U.S. $300,000,000 THIRD AMENDED AND RESTATED FIVE-YEAR CREDIT AGREEMENT Dated as of February 18, 2026 among PINNACLE WEST CAPITAL CORPORATION, as Borrower, THE LENDERS PARTY HERETO, BARCLAYS BANK PLC, as Agent and Issuing Bank, PNC BANK, NATIONAL ASSOCIATION and WELLS FARGO BANK, NATIONAL ASSOCIATION, as Co-Syndication Agents, PNC BANK, NATIONAL ASSOCIATION, WELLS FARGO BANK, NATIONAL

U.S. $300,000,000 THIRD AMENDED AND RESTATED FIVE-YEAR CREDIT AGREEMENT Dated as of February 18, 2026 PINNACLE WEST CAPITAL CORPORATION, as Borrower, THE LENDERS PARTY HERETO, BARCLAYS BANK PLC, as Agent and Issuing Bank, PNC BANK, NATIONAL ASSOCIATI

Exhibit 10.1 U.S. $300,000,000 THIRD AMENDED AND RESTATED FIVE-YEAR CREDIT AGREEMENT Dated as of February 18, 2026 among PINNACLE WEST CAPITAL CORPORATION, as Borrower, THE LENDERS PARTY HERETO, BARCLAYS BANK PLC, as Agent and Issuing Bank, PNC BANK, NATIONAL ASSOCIATION and WELLS FARGO BANK, NATIONAL ASSOCIATION, as Co-Syndication Agents, PNC BANK, NATIONAL ASSOCIATION, WELLS FARGO BANK, NATIONAL

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 17, 2026 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

U.S. $1,700,000,000 AMENDED AND RESTATED FIVE-YEAR CREDIT AGREEMENT Dated as of February 18, 2026 ARIZONA PUBLIC SERVICE COMPANY, as Borrower, THE LENDERS PARTY HERETO, BARCLAYS BANK PLC, as Agent and Issuing Bank, PNC BANK, NATIONAL ASSOCIATION WELL

Exhibit 10.2 U.S. $1,700,000,000 AMENDED AND RESTATED FIVE-YEAR CREDIT AGREEMENT Dated as of February 18, 2026 among ARIZONA PUBLIC SERVICE COMPANY, as Borrower, THE LENDERS PARTY HERETO, BARCLAYS BANK PLC, as Agent and Issuing Bank, PNC BANK, NATIONAL ASSOCIATION and WELLS FARGO BANK, NATIONAL ASSOCIATION, as Co-Syndication Agents, PNC BANK, NATIONAL ASSOCIATION, WELLS FARGO BANK, NATIONAL ASSOCI

U.S. $1,700,000,000 AMENDED AND RESTATED FIVE-YEAR CREDIT AGREEMENT Dated as of February 18, 2026 ARIZONA PUBLIC SERVICE COMPANY, as Borrower, THE LENDERS PARTY HERETO, BARCLAYS BANK PLC, as Agent and Issuing Bank, PNC BANK, NATIONAL ASSOCIATION WELL

Exhibit 10.2 U.S. $1,700,000,000 AMENDED AND RESTATED FIVE-YEAR CREDIT AGREEMENT Dated as of February 18, 2026 among ARIZONA PUBLIC SERVICE COMPANY, as Borrower, THE LENDERS PARTY HERETO, BARCLAYS BANK PLC, as Agent and Issuing Bank, PNC BANK, NATIONAL ASSOCIATION and WELLS FARGO BANK, NATIONAL ASSOCIATION, as Co-Syndication Agents, PNC BANK, NATIONAL ASSOCIATION, WELLS FARGO BANK, NATIONAL ASSOCI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 7, 2025 Commission File Nu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 7, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Registrant's telephone Number, Including Area Code) IRS Employer Identification No.

Powering Arizona’s Future November Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking st

novemberinvestordeck Powering Arizona’s Future November Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact name of re

Powering Arizona’s Future Third-Quarter Financial Results November 3, 2025 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. Th

q32025earningsfinal Powering Arizona’s Future Third-Quarter Financial Results November 3, 2025 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

PINNACLE WEST REPORTS 2025 THIRD-QUARTER FINANCIAL RESULTS

Exhibit 99.1 FOR IMMEDIATE RELEASE November 3, 2025 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Website: pinnaclewest.com PINNACLE WEST REPORTS 2025 THIRD-QUARTER FINANCIAL RESULTS •Customer growth, summer heat drive increase in sales and usage •Operating performance, customer reliability remain strong •Company expands support for community and utility bill

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 3, 2025 Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 3, 2025 Commission File Number Exact name of registrant as specified in its charter; State or other jurisdiction of incorporation or organization; Address of principal execut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): October 14, 2025 Commission File Nu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): October 14, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Registrant's telephone Number, Including Area Code) IRS Employer Identification No.

Renewed, Reliable and Resilient October Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looki

octoberinvestordeck Renewed, Reliable and Resilient October Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 28, 2025 Commission File Num

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 28, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Registrant's telephone Number, Including Area Code) IRS Employer Identification No.

Renewed, Reliable and Resilient September Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-loo

septemberinvestordeck Renewed, Reliable and Resilient September Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Very truly yours,

Exhibit 10.1 To: Pinnacle West Capital Corporation (“Party B”) 400 North Fifth Street, Mail Station 9996 Phoenix, Arizona 85004 From: Wells Fargo Bank, National Association (“Party A”) 30 Hudson Yards, 14th Floor New York, NY 10001-2170 Re: Amendment to Share Forward Transactions Date: August 28, 2025 Ladies and Gentlemen: This letter agreement (this “Amendment”) amends each of the Confirmation da

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): September 2, 2025 Commission File N

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): September 2, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Registrant's telephone Number, Including Area Code) IRS Employer Identification No.

ARIZONA PUBLIC SERVICE COMPANY 5.90% Note due 2055

Exhibit 4.4 UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO ARIZONA PUBLIC SERVICE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAY

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 15, 2025 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Item 14. Other Expenses of Issuance and Distribution.

Exhibit 99.1 Item 14. Other Expenses of Issuance and Distribution. The expenses, other than underwriting discounts and commissions, to be incurred by Arizona Public Service Company (“APS”) relating to the offering of $250,000,000 principal amount of its 5.70% Notes due 2034 and $700,000,000 principal amount of its 5.90% Notes due 2055, under APS’s Registration Statement on Form S-3 (No. 333-277448

ARIZONA PUBLIC SERVICE COMPANY 5.70% Note due 2034

Exhibit 4.3 UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO ARIZONA PUBLIC SERVICE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAY

ARIZONA PUBLIC SERVICE COMPANY $250,000,000 5.70% Notes due 2034 $700,000,000 5.90% Notes due 2055 UNDERWRITING AGREEMENT

Exhibit 1.1 ARIZONA PUBLIC SERVICE COMPANY $250,000,000 5.70% Notes due 2034 $700,000,000 5.90% Notes due 2055 UNDERWRITING AGREEMENT August 12, 2025 Barclays Capital Inc. PNC Capital Markets LLC 745 Seventh Avenue 300 Fifth Avenue, Floor 10 New York, New York 10019 Pittsburgh, Pennsylvania 15222 BMO Capital Markets Corp. TD Securities (USA) LLC 151 W. 42nd St. 1 Vanderbilt Avenue, 11th Floor New

ARIZONA PUBLIC SERVICE COMPANY

  Exhibit 4.2     ARIZONA PUBLIC SERVICE COMPANY   TO   THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.   As Trustee under Arizona Public Service Company’s Indenture dated as of January 15, 1998   Thirty-Second Supplemental Indenture   Dated as of August 15, 2025   5.90% Notes due 2055       This THIRTY-SECOND SUPPLEMENTAL INDENTURE, dated as of August 15, 2025, is between Arizona Public Service C

Renewed, Reliable and Resilient Second-Quarter Financial Results August 6, 2025 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goal

q22025xearningsxfinal Renewed, Reliable and Resilient Second-Quarter Financial Results August 6, 2025 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 6, 2025 Commission File Numb

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 6, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Registrant's telephone Number, Including Area Code) IRS Employer Identification No.

Renewed, Reliable and Resilient August Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-lookin

augustinvestordeck Renewed, Reliable and Resilient August Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Pinnacle West Articles of Incorporation, restated as of May 2

Exhibit 3.1 RESTATED ARTICLES OF INCORPORATION OF PINNACLE WEST CAPITAL CORPORATION (RESTATED AS OF MAY 22, 2025) FIRST: The name of the corporation is Pinnacle West Capital Corporation. SECOND: The corporation is organized for the purpose of transacting any or all lawful business for which corporations may be incorporated under Chapter 1 of Title 10, Arizona Revised Statutes, as at any time in ef

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 6, 2025 Commission File Numb

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 6, 2025 Commission File Number Exact name of each registrant as specified in its charter; State or other jurisdiction of incorporation or organization; Address of principal executive offices, including zip code; and Registrant's telephone number, including area code IRS Employer Identification No.

APS Articles of Incorporation, restated as of May 16, 2012

Exhibit 3.3 ARTICLES OF INCORPORATION OF ARIZONA PUBLIC SERVICE COMPANY (RESTATED AS OF MAY 16, 2012) FIRST: The name of the Corporation is Arizona Public Service Company. SECOND: The purposes for which this Corporation is organized include the transaction of any or all lawful business for which corporations may be incorporated under Chapter 1 of Title 10, Arizona Revised Statutes, on or at any ti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact name of each re

PINNACLE WEST REPORTS LOWER 2025 SECOND-QUARTER FINANCIAL RESULTS COMPARED TO A YEAR AGO

Exhibit 99.1 FOR IMMEDIATE RELEASE August 6, 2025 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Website: pinnaclewest.com PINNACLE WEST REPORTS LOWER 2025 SECOND-QUARTER FINANCIAL RESULTS COMPARED TO A YEAR AGO •Milder weather drives quarter-over-quarter earnings decrease •Operating performance, reliability remain strong amidst robust customer and sales growt

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): July 22, 2025 Commission File Numbe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): July 22, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Telephone Number, Including Area Code) IRS Employer Identification No.

Renewed, Reliable and Resilient July Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking

julyinvestordeck Renewed, Reliable and Resilient July Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 13, 2025 C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K/A (Amendment No.

Regulation FD Disclosure, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 13, 2025 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

APS REQUESTS RATE ADJUSTMENT TO SUPPORT RELIABLE SERVICE FOR CUSTOMERS New rates would not go into effect until the second half of 2026, if approved by the ACC

Exhibit 99.1 FOR IMMEDIATE RELEASE June 13, 2025 Media Contact: Investor Relations: Ann Porter Amanda Ho 602-538-0588 602-250-3334 Page 1 of 3 Website: aps.com/newsroom APS REQUESTS RATE ADJUSTMENT TO SUPPORT RELIABLE SERVICE FOR CUSTOMERS New rates would not go into effect until the second half of 2026, if approved by the ACC PHOENIX – Arizona Public Service (APS) today filed an application with

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 (Mark One) ý ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. For the fiscal year ended December 31, 2024 OR o TRANSITION REPORT PURSUANT TO 15(d) OF

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 27, 2025 Commission File Number

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 27, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Telephone Number, Including Area Code) IRS Employer Identification No.

Renewed, Reliable and Resilient May Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking s

mayinvestordeck Renewed, Reliable and Resilient May Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 21, 2025 Commission File Number

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 21, 2025 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Sixth Supplemental Indenture relating to the issuance of $400,000,000 of 4.90% Senior Notes Due 2028 and $400,000,000 of 5.15% Senior Notes Due 2030

Exhibit 4.1 PINNACLE WEST CAPITAL CORPORATION TO THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. As Trustee under Pinnacle West Capital Corporation’s Indenture dated as of December 1, 2000 (For Senior Securities) Sixth Supplemental Indenture Dated as of May 15, 2025 4.90% Senior Notes due 2028 5.15% Senior Notes due 2030 This SIXTH SUPPLEMENTAL INDENTURE, dated as of May 15, 2025, is between Pinna

Specimen Note of 4.90% Senior Notes due 2028

Exhibit 4.2 UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO PINNACLE WEST CAPITAL CORPORATION OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY

Specimen Note of 5.15% Senior Notes due 2030

Exhibit 4.3 UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO PINNACLE WEST CAPITAL CORPORATION OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY

Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 12, 2025 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Underwriting Agreement dated May 12, 2025, in connection with the offering of $400,000,000 of 4.90% Senior Notes Due 2028 and 5.15% Senior Notes Due 2030

Exhibit 1.1 PINNACLE WEST CAPITAL CORPORATION $400,000,000 4.90% Senior Notes due 2028 $400,000,000 5.15% Senior Notes due 2030 UNDERWRITING AGREEMENT May 12, 2025 Citigroup Global Markets Inc. 388 Greenwich Street New York, New York 10013 J.P. Morgan Securities LLC 383 Madison Avenue New York, New York 10179 RBC Capital Markets, LLC Brookfield Place 200 Vesey Street, 8th Floor New York, New York

Item 14. Other Expenses of Issuance and Distribution.

Exhibit 99.1 Item 14. Other Expenses of Issuance and Distribution. The expenses, other than underwriting discounts and commissions, to be incurred by Pinnacle West Capital Corporation (the “Company”) relating to the offering of $400,000,000 principal amount of its 4.90% Senior Notes due 2028 and of $400,000,000 principal amount of its 5.15% Senior Notes due 2030, under the Company’s Registration S

Table 1: Newly Registered and Carry Forward Securities

Calculation of Filing Fee Tables S-3 PINNACLE WEST CAPITAL CORP Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Debt 4.

PROSPECTUS SUPPLEMENT (To Prospectus Dated February 28, 2024) Pinnacle West Capital Corporation $400,000,000 4.90% Senior Notes due 2028 $400,000,000 5.15% Senior Notes due 2030

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(2)  Registration No. 333-277448 PROSPECTUS SUPPLEMENT (To Prospectus Dated February 28, 2024) $800,000,000 Pinnacle West Capital Corporation $400,000,000 4.90% Senior Notes due 2028 $400,000,000 5.15% Senior Notes due 2030 This is an offering by Pinnacle West Capital Corporation of $400,000,000 of its 4.90% Senior Notes due 2028, referred to in this

Final Term Sheet Pinnacle West Capital Corporation $400,000,000 4.90% Senior Notes due 2028 $400,000,000 5.15% Senior Notes due 2030 May 12, 2025

Filed under Rule 433 File No. 333-277448 Final Term Sheet Pinnacle West Capital Corporation $400,000,000 4.90% Senior Notes due 2028 $400,000,000 5.15% Senior Notes due 2030 May 12, 2025 Issuer: Pinnacle West Capital Corporation Expected Ratings (Moody’s / S&P / Fitch): Baa2 (stable) / BBB (stable) / BBB (stable) Note: A securities rating is not a recommendation to buy, sell or hold securities and

SUBJECT TO COMPLETION, DATED MAY 12, 2025 PRELIMINARY PROSPECTUS SUPPLEMENT (To Prospectus Dated February 28, 2024) Pinnacle West Capital Corporation $    % Senior Notes due 20   $    % Senior Notes due 20  

TABLE OF CONTENTS The information in this preliminary prospectus supplement is not complete and may be changed.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact name of each r

PINNACLE WEST REPORTS LOWER FIRST-QUARTER FINANCIAL RESULTS

Exhibit 99.1 FOR IMMEDIATE RELEASE May 1, 2025 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Website: pinnaclewest.com PINNACLE WEST REPORTS LOWER FIRST-QUARTER FINANCIAL RESULTS •Results in line with company's expectations; full year 2025 earnings guidance affirmed •Planned power plant outages contribute to higher operations and maintenance expenses versus a

Renewed, Reliable and Resilient First-Quarter Financial Results May 1, 2025 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. T

Renewed, Reliable and Resilient First-Quarter Financial Results May 1, 2025 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 1, 2025 Commission File Number Exact name of each registrant as specified in its charter; State or other jurisdiction of incorporation or organization; Address of principal executive offices, including zip code; and Telephone number, including area code IRS Employer Identification No.

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. )

Back to Content 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.

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. )

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.

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. )

Back to Content 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.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 3, 2025 Commission File Numbe

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 3, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Telephone Number, Including Area Code) IRS Employer Identification No.

Renewed, Reliable and Resilient March Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking

marchinvestordeck Renewed, Reliable and Resilient March Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 25, 2025 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

ARS

2024 ANNUAL REPORT PINNACLE WEST CAPITAL CORPORATIONArizona continues to be a highly attractive destination for both residents and businesses.

Summary of 2025 Variable Incentive Plan and Officer Variable Incentive Plan

Exhibit 10.6(4) Summary of 2025 Incentive Plans On December 10, 2024, the Human Resources Committee (the “Committee”) of the Pinnacle West Capital Corporation (“Pinnacle West”) Board of Directors (the “Board”) approved the portion of the Arizona Public Service Company (“APS”) 2025 Annual Incentive Award Plan (the “APS Plan”) that provides an incentive award opportunity for Jeffrey B. Guldner, Chai

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact Name of Each Regist

PINNACLE WEST REPORTS 2024 FULL-YEAR AND FOURTH-QUARTER RESULTS

Exhibit 99.1 FOR IMMEDIATE RELEASE February 25, 2025 Media Contact: Alan Bunnell (602) 250-3376 Analyst Contacts: Amanda Ho (602) 250-3334 Website: pinnaclewest.com PINNACLE WEST REPORTS 2024 FULL-YEAR AND FOURTH-QUARTER RESULTS •New customer rates, retail sales growth of 5.7% and an exceptionally hot summer contribute to an increase in retail revenue and full-year financial results •Annual retail

Securities Trading Policy of Pinnacle West

Exhibit 19.1 SECURITIES TRADING POLICY 1.PURPOSE AND APPLICABILITY 1.1This policy ensures that our Directors, officers, employees, and contractors comply with federal and state securities laws and avoid even the appearance of questionable or improper conduct in connection with securities transactions. 1.2This policy covers members of the Board of Directors (“Directors”), officers, employees, and c

Description of Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934

Exhibit 4.9 DESCRIPTION OF THE REGISTRANTS’ SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 Pinnacle West Capital Corporation (“Pinnacle West”) The following description of Pinnacle West’s securities registered pursuant to Section 12 of the Securities Exchange Act of 1934 is a summary and does not purport to be complete. The description is subject to, and qualif

Renewed, Reliable and Resilient Fourth-Quarter and Full-Year 2024 Financial Results February 25, 2025 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and fina

Renewed, Reliable and Resilient Fourth-Quarter and Full-Year 2024 Financial Results February 25, 2025 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Subsidiaries of Pinnacle West

Exhibit 21.1 SUBSIDIARIES LIST Arizona Public Service Company *All other subsidiaries of Pinnacle West Capital Corporation and all subsidiaries of Arizona Public Service Company have been omitted as they do not constitute significant subsidiaries within the meaning of Rule 1-02(w) of Regulation S-X.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 19, 2025 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Renewed, Reliable and Resilient January Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looki

Renewed, Reliable and Resilient January Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 6, 2025 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Telephone Number, Including Area Code) IRS Employer Identification No.

PINNACLE WEST AND APS ANNOUNCE LEADERSHIP SUCCESSION

EX-99.1 2 ex991.htm EX-99.1 Exhibit 99.1 FOR IMMEDIATE RELEASE December 12, 2024 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Media Hotline (602) 250-2277 Amanda Ho (602) 250-3334 Page 1 of 2 Website: pinnaclewest.com PINNACLE WEST AND APS ANNOUNCE LEADERSHIP SUCCESSION PHOENIX – Pinnacle West Capital Corp. (NYSE: PNW) announced today that Pinnacle West and Arizona Public Service (A

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 11, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 10, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

PNW / Pinnacle West Capital Corporation / BARROW HANLEY MEWHINNEY & STRAUSS LLC - SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Pinnacle West Capital Corp (Name of Issuer) Common Stock (Title of Class of Securities) 723484101 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Statement) Check appropriate box to designate the rule pursuant to which this

PNW / Pinnacle West Capital Corporation / Capital Research Global Investors - SEC SCHEDULE 13G Passive Investment

SC 13G/A 1 SEC13GFiling.htm SEC SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2 )* Pinnacle West Capital Corp. (Name of Issuer) Common Stock (Title of Class of Securities) 723484101 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Statement) Check the appropria

Equity Distribution Agreement, dated November 8, 2024, among Pinnacle West Capital Corporation and 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, Bank of America, N.A., Barclays Bank PLC, JPMorgan Chase Bank, National Association, Mizuho Markets Americas LLC, MUFG Securities EMEA plc, The Toronto-Dominion Bank, Truist Bank and Wells Fargo Bank, National Association or one or more of their respective affiliates, as forward purchasers, and 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 forward sellers.

Exhibit 1.1 PINNACLE WEST CAPITAL CORPORATION COMMON STOCK (NO PAR VALUE) EQUITY DISTRIBUTION AGREEMENT NOVEMBER 8, 2024 November 8, 2024 To: BofA Securities, Inc. One Bryant Park New York, New York 10036 Bank of America, N.A. One Bryant Park New York, New York 10036 BofA Securities, Inc. One Bryant Park New York, New York 10036 Barclays Capital Inc. 745 Seventh Avenue New York, New York 10019 Bar

Pinnacle West Capital Corporation Shares of Common Stock Having an Aggregate Gross Sales Price of Up To $900,000,000

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(5)  Registration No. 333-277448 PROSPECTUS SUPPLEMENT (To Prospectus dated February 28, 2024) Pinnacle West Capital Corporation Shares of Common Stock Having an Aggregate Gross Sales Price of Up To $900,000,000 We have entered into an equity distribution agreement with BofA Securities, Inc., Barclays Capital Inc., J.P. Morgan Securities LLC, Mizuho

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 8, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Telephone Number, Including Area Code) IRS Employer Identification No.

Renewed, Reliable and Resilient November Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-look

Renewed, Reliable and Resilient November Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Table 1: Newly Registered and Carry Forward Securities

Calculation of Filing Fee Tables S-3 PINNACLE WEST CAPITAL CORP Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Newly Registered Securities Fees to be Paid 1 Equity Common Stock 457(r) $ 900,000,000.

Equity Distribution Agreement, dated November 8, 2024, among Pinnacle West Capital Corporation and 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, Bank of America, N.A., Barclays Bank PLC, JPMorgan Chase Bank, National Association, Mizuho Markets Americas LLC, MUFG Securities EMEA plc, The Toronto-Dominion Bank, Truist Bank and Wells Fargo Bank, National Association or one or more of their respective affiliates, as forward purchasers, and 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 forward sellers.

Exhibit 1.1 PINNACLE WEST CAPITAL CORPORATION COMMON STOCK (NO PAR VALUE) EQUITY DISTRIBUTION AGREEMENT NOVEMBER 8, 2024 November 8, 2024 To: BofA Securities, Inc. One Bryant Park New York, New York 10036 Bank of America, N.A. One Bryant Park New York, New York 10036 BofA Securities, Inc. One Bryant Park New York, New York 10036 Barclays Capital Inc. 745 Seventh Avenue New York, New York 10019 Bar

Entry into a Material Definitive Agreement, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K/A (Amendment No.

Entry into a Material Definitive Agreement, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 8, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Offices, and Zip Code; and Telephone Number, Including Area Code) IRS Employer Identification No.

PNW / Pinnacle West Capital Corporation / BlackRock, Inc. Passive Investment

SC 13G/A 1 us7234841010110724.txt us7234841010110724.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 16) PINNACLE WEST CAPITAL CORP - (Name of Issuer) Common Stock - (Title of Class of Securities) 723484101 - (CUSIP Number) October 31, 2024 - (Date of Event Which Requires Filing of this Statement) Check the appropr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact Name of Ea

PINNACLE WEST REPORTS SLIGHTLY LOWER 2024 THIRD-QUARTER RESULTS COMPARED TO A YEAR AGO

Exhibit 99.1 FOR IMMEDIATE RELEASE November 6, 2024 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Website: pinnaclewest.com PINNACLE WEST REPORTS SLIGHTLY LOWER 2024 THIRD-QUARTER RESULTS COMPARED TO A YEAR AGO •Record-setting summer heat drives increase in customer sales and usage •Operating performance, reliability remain strong for customers •Creative appr

Renewed, Reliable and Resilient Third-Quarter 2024 Financial Results November 6, 2024 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook an

q32024xearnings Renewed, Reliable and Resilient Third-Quarter 2024 Financial Results November 6, 2024 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 6, 2024 Commission File Nu

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 6, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Telephone Number, Including Area Code) IRS Employer Identification No.

Renewed, Reliable and Resilient October Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looki

Renewed, Reliable and Resilient October Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): September 30, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Telephone Number, Including Area Code) IRS Employer Identification No.

Renewed, Reliable and Resilient September Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-loo

Renewed, Reliable and Resilient September Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): September 3, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Telephone Number, Including Area Code) IRS Employer Identification No.

ive-Year Credit Agreement, dated as of April 10, 2023, among APS, as Borrower, Barclays Bank PLC, as Agent, Co-Sustainability Structuring Agent and Issuing Bank, and the lenders and other parties thereto

Exhibit 10.2 AMENDMENT NO. 1 TO FIVE-YEAR CREDIT AGREEMENT THIS AMENDMENT NO. 1 TO FIVE-YEAR CREDIT AGREEMENT (this “Amendment”) is made as of August 2, 2024, by and among ARIZONA PUBLIC SERVICE COMPANY (the “Borrower”), the lenders listed on the signature pages hereof (the “Lenders”), and BARCLAYS BANK PLC (“Barclays”), as Agent (the “Agent”), under that certain Five-Year Credit Agreement, dated

econd Amended and Restated Five-Year Credit Agreement, dated as of April 10, 2023, among Pinnacle West, as Borrower, Barclays Bank PLC, as Agent, Co-Sustainability Structuring Agent and Issuing Bank, and the lenders and other parties thereto

Exhibit 10.1 AMENDMENT NO. 1 TO SECOND AMENDED AND RESTATED FIVE-YEAR CREDIT AGREEMENT THIS AMENDMENT NO. 1 TO SECOND AMENDED AND RESTATED FIVE-YEAR CREDIT AGREEMENT (this “Amendment”) is made as of August 2, 2024, by and among PINNACLE WEST CAPITAL CORPORATION (the “Borrower”), the lenders listed on the signature pages hereof (the “Lenders”), and BARCLAYS BANK PLC (“Barclays”), as Agent (the “Age

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 2, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Telephone Number, Including Area Code) IRS Employer Identification No.

Renewed, Reliable and Resilient Second-Quarter 2024 Financial Results August 1, 2024 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and

Renewed, Reliable and Resilient Second-Quarter 2024 Financial Results August 1, 2024 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

PINNACLE WEST REPORTS IMPROVED SECOND-QUARTER FINANCIAL RESULTS

Exhibit 99.1 FOR IMMEDIATE RELEASE August 1, 2024 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Website: pinnaclewest.com PINNACLE WEST REPORTS IMPROVED SECOND-QUARTER FINANCIAL RESULTS •New customer rates, record heat positively impact quarter-over-quarter earnings •Customer and sales growth continue to reflect a strong Arizona economy •Expanded bill assista

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 1, 2024 Commission File Number Exact Name of Registrant as Specified in Charter; State or Other Jurisdiction of Incorporation; Address of Principal Executive Officers, and Zip Code; and Telephone Number, Including Area Code) IRS Employer Identification No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact Name of Each Re

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 19, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

PINNACLE WEST APPOINTS THREE NEW MEMBERS TO ITS BOARD OF DIRECTORS Additions Butler, Eicher & Flanagan bring diverse experience, financial acumen

Exhibit 99.1 FOR IMMEDIATE RELEASE June 20, 2024 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Website: pinnaclewest.com PINNACLE WEST APPOINTS THREE NEW MEMBERS TO ITS BOARD OF DIRECTORS Additions Butler, Eicher & Flanagan bring diverse experience, financial acumen PHOENIX – Pinnacle West Capital Corp. (NYSE: PNW) announced today that its board of directors

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 (Mark One) ý ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. For the fiscal year ended December 31, 2023 OR o TRANSITION REPORT PURSUANT TO 15(d) OF

Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 5, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Underwriting Agreement dated June 5, 2024, in connection with the offering of $350,000,000 of Floating Rate Notes Due 2026

Exhibit 1.1 PINNACLE WEST CAPITAL CORPORATION $350,000,000 Floating Rate Senior Notes due 2026 UNDERWRITING AGREEMENT June 5, 2024 Truist Securities, Inc. 3333 Peachtree Road NE, 11th Floor Atlanta, Georgia 30326 Ladies and Gentlemen: 1.             Introduction. Pinnacle West Capital Corporation, an Arizona corporation (the “Company”), proposes to issue and sell to Truist Securities, Inc. (the “U

Fifth Supplemental Indenture relating to the issuance of $350,000,000 of Floating Rate Senior Notes Due 2026

Exhibit 4.1 PINNACLE WEST CAPITAL CORPORATION TO THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. As Trustee under Pinnacle West Capital Corporation’s Indenture dated as of December 1, 2000 (For Senior Securities) Fifth Supplemental Indenture Dated as of June 10, 2024 Floating Rate Senior Notes due 2026 This FIFTH SUPPLEMENTAL INDENTURE, dated as of June 10, 2024, is between Pinnacle West Capital C

Item 14. Other Expenses of Issuance and Distribution.

Exhibit 99.1 Item 14. Other Expenses of Issuance and Distribution. The expenses, other than underwriting discounts and commissions, to be incurred by Pinnacle West Capital Corporation (the “Company”) relating to the offering of $350,000,000 principal amount of its Floating Rate Senior Notes due 2026, under the Company’s Registration Statement on Form S-3 (No. 333-277448) and a related prospectus s

Calculation of Filing Fee Table(1) (Form Type) Pinnacle West Capital Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities

Exhibit 107 Calculation of Filing Fee Table(1) 424(b)(2) (Form Type) Pinnacle West Capital Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Newly Registered Securities Fees to Be Paid Debt Floating Rate Senior Notes due 2026 Rule 457(r) $350,000,000 100% $350,000,000 $147.

Indenture, dated as of June 6, 2024, between Pinnacle West and The Bank of New York Mellon Trust Company, N.A., as trustee

Exhibit 4.1 Execution Version PINNACLE WEST CAPITAL CORPORATION AND THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., as Trustee INDENTURE Dated as of June 6, 2024 4.75% Convertible Senior Notes due 2027 TABLE OF CONTENTS Page Article 1 Definitions Section 1.01. Definitions 1 Section 1.02. References to Interest 13 Article 2 Issue, Description, Execution, Registration and Exchange of Notes Section

Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 6, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

$350,000,000 Pinnacle West Capital Corporation Floating Rate Senior Notes due 2026

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(2)  Registration No. 333-277448 PROSPECTUS SUPPLEMENT (To Prospectus Dated February 28, 2024) $350,000,000 Pinnacle West Capital Corporation Floating Rate Senior Notes due 2026 This is an offering by Pinnacle West Capital Corporation of $350,000,000 of its Floating Rate Senior Notes due 2026, referred to in this prospectus supplement as the “notes.”

Final Term Sheet Pinnacle West Capital Corporation $350,000,000 Floating Rate Senior Notes due 2026 June 5, 2024

Filed under Rule 433 File No. 333-277448 Final Term Sheet Pinnacle West Capital Corporation $350,000,000 Floating Rate Senior Notes due 2026 June 5, 2024 Issuer: Pinnacle West Capital Corporation Expected Ratings (Moody’s / S&P / Fitch): Baa2 (Stable) / BBB (Stable) / BBB (Stable) Note: A securities rating is not a recommendation to buy, sell or hold securities and may be subject to revision or wi

SUBJECT TO COMPLETION, DATED JUNE 5, 2024

TABLE OF CONTENTS The information in this preliminary prospectus supplement is not complete and may be changed.

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 4, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

PINNACLE WEST UPSIZES AND PRICES OFFERING OF $475 MILLION OF 4.75% CONVERTIBLE SENIOR NOTES DUE 2027

Exhibit 99.1 FOR IMMEDIATE RELEASE June 4, 2024 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho   (602) 250-3334 Page 1 of 2 PINNACLE WEST UPSIZES AND PRICES OFFERING OF $475 MILLION OF 4.75% CONVERTIBLE SENIOR NOTES DUE 2027 PHOENIX – Pinnacle West Capital Corp. (NYSE: PNW) (“Pinnacle West”) announced the pricing of its offering of $475 million aggregate principal amount of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 3, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Renewed, Reliable and Resilient June Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking

Renewed, Reliable and Resilient June Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): June 3, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

PINNACLE WEST ANNOUNCES PROPOSED OFFERING OF $450 MILLION OF CONVERTIBLE SENIOR NOTES DUE 2027

Exhibit 99.1 FOR IMMEDIATE RELEASE June 3, 2024 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Page 1 of 2 PINNACLE WEST ANNOUNCES PROPOSED OFFERING OF $450 MILLION OF CONVERTIBLE SENIOR NOTES DUE 2027 PHOENIX – Pinnacle West Capital Corp. (NYSE: PNW) (“Pinnacle West”) announced today that it intends to offer, subject to market and other conditions, $450 milli

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 22, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Item 14. Other Expenses of Issuance and Distribution.

Exhibit 99.1 Item 14. Other Expenses of Issuance and Distribution. The expenses, other than underwriting discounts and commissions, to be incurred by Arizona Public Service Company (“APS”) relating to the offering of $450,000,000 principal amount of its 5.70% Notes due 2034, under APS’s Registration Statement on Form S-3 (No. 333-277448-01) and a related prospectus supplement filed with the Securi

Underwriting Agreement dated May 6, 2024, in connection with the offering of $450,000,000 of 5.70% Notes due 2034

Exhibit 1.1 ARIZONA PUBLIC SERVICE COMPANY $450,000,000 5.70% Notes due 2034 UNDERWRITING AGREEMENT May 6, 2024 MUFG Securities Americas Inc. 1221 Avenue of the Americas, 6th Floor New York, New York 10020 PNC Capital Markets LLC 300 Fifth Avenue, Floor 10 Pittsburgh, Pennsylvania 15222 As Representatives of the several Underwriters named in Exhibit A hereto Ladies and Gentlemen: 1.            Int

Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 9, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Thirty-First Supplemental Indenture relating to the issuance of $450,000,000 of 5.70 Notes due 2034

Exhibit 4.1 ARIZONA PUBLIC SERVICE COMPANY TO THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. As Trustee under Arizona Public Service Company’s Indenture dated as of January 15, 1998 Thirty-First Supplemental Indenture Dated as of May 9, 2024 5.70% Notes due 2034 This THIRTY-FIRST SUPPLEMENTAL INDENTURE, dated as of May 9, 2024, is between Arizona Public Service Company, a corporation duly organiz

Specimen Note of 5.70% Notes due 2034

Exhibit 4.2 UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO ARIZONA PUBLIC SERVICE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAY

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 7, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Renewed, Reliable and Resilient May Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking s

Renewed, Reliable and Resilient May Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

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. )

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.

PINNACLE WEST REPORTS 2024 FIRST-QUARTER RESULTS

Exhibit 99.1 FOR IMMEDIATE RELEASE May 2, 2024 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Website: pinnaclewest.com PINNACLE WEST REPORTS 2024 FIRST-QUARTER RESULTS •Improved quarterly results impacted by customer growth, increased sales and new rates •APS employees focus on summer preparedness, reliability and resilience •Company reaffirms full-year 2024

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 2, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact Name of Each R

Summary of 2024 Variable Incentive Plan and Officer Variable Incentive Plan

Exhibit 10.1 Summary of 2024 Incentive Plans On March 20, 2024, the Human Resources Committee (the “Committee”) of the Pinnacle West Capital Corporation (“Pinnacle West”) Board of Directors (the “Board”) approved the portion of the Arizona Public Service Company (“APS”) 2024 Annual Incentive Award Plan (the “APS Plan”) that provides an incentive award opportunity for Jeffrey B. Guldner, Chairman o

Renewed, Reliable and Resilient First-Quarter 2024 Financial Results May 2, 2024 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goa

Renewed, Reliable and Resilient First-Quarter 2024 Financial Results May 2, 2024 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): April 8, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Renewed, Reliable and Resilient April Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking

aprilinvestordeck Renewed, Reliable and Resilient April Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

COURTESY PDF OF PROXY STATEMENT

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.

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. )

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.

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. )

Back to Contents 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.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 20, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

PNW / Pinnacle West Capital Corporation / Capital Research Global Investors - SEC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1 )* Pinnacle West Capital Corp. (Name of Issuer) Common Stock (Title of Class of Securities) 723484101 (CUSIP Number) February 29, 2024 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 28, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Forward Sale Agreement, dated February 28, 2024, between Pinnacle West and Mizuho Markets Americas LLC (with Mizuho Securities USA LLC acting as its agent)

Exhibit 10.3 February 28, 2024 To: Pinnacle West Capital Corporation 400 North Fifth Street, Mail Station 9996 Phoenix, Arizona 85004 From: Mizuho Markets Americas LLC c/o Mizuho Securities USA LLC 1271 Avenue of the Americas New York, NY 10020 Dear Sirs, The purpose of this letter agreement (this “Forward Confirmation”) is to confirm the terms and conditions of the transaction entered into betwee

Underwriting Agreement, dated February 28, 2024, among Pinnacle West Capital Corporation, Barclays Capital Inc., Citigroup Global Markets Inc., Mizuho Securities USA LLC and Wells Fargo Securities, LLC, as representatives of the several underwriters named therein, Mizuho Securities USA LLC, as a forward seller, Mizuho Markets Americas LLC, as a forward purchaser, Wells Fargo Securities, LLC, as a forward seller and Wells Fargo Bank, National Association, as a forward purchaser.

Exhibit 1.1 PINNACLE WEST CAPITAL CORPORATION Common Stock UNDERWRITING AGREEMENT February 28, 2024 Barclays Capital Inc. 745 Seventh Avenue New York, New York 10019 Citigroup Global Markets Inc. 388 Greenwich Street New York, New York 10013 Mizuho Securities USA LLC 1271 Avenue of the Americas New York, New York 10020 Wells Fargo Securities, LLC 500 West 33rd Street, 14th Floor New York, New York

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): March 4, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Additional Forward Sale Agreement, dated February 28, 2024, between Pinnacle West and Wells Fargo Bank, National Association

Exhibit 10.2 February 29, 2024 To: Pinnacle West Capital Corporation 400 North Fifth Street, Mail Station 9996 Phoenix, Arizona 85004 From: Wells Fargo Bank, National Association 30 Hudson Yards New York, NY 10001-2170 Dear Sirs, The purpose of this letter agreement (this “Forward Confirmation”) is to confirm the terms and conditions of the transaction entered into between Party A and Party B on t

Additional Forward Sale Agreement, dated February 28, 2024, between Pinnacle West and Mizuho Markets Americas LLC (with Mizuho Securities USA LLC acting as its agent)

Exhibit 10.4 February 29, 2024 To: Pinnacle West Capital Corporation 400 North Fifth Street, Mail Station 9996 Phoenix, Arizona 85004 From: Mizuho Markets Americas LLC c/o Mizuho Securities USA LLC 1271 Avenue of the Americas New York, NY 10020 Dear Sirs, The purpose of this letter agreement (this “Forward Confirmation”) is to confirm the terms and conditions of the transaction entered into betwee

Renewed, Reliable and Resilient March Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward-looking

Renewed, Reliable and Resilient March Investor Meetings 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Forward Sale Agreement, dated February 28, 2024, between Pinnacle West and Wells Fargo Bank, National Association

Exhibit 10.1 February 28, 2024 To: Pinnacle West Capital Corporation 400 North Fifth Street, Mail Station 9996 Phoenix, Arizona 85004 From: Wells Fargo Bank, National Association 30 Hudson Yards New York, NY 10001-2170 Dear Sirs, The purpose of this letter agreement (this “Forward Confirmation”) is to confirm the terms and conditions of the transaction entered into between Party A and Party B on t

9,774,436 Shares Pinnacle West Capital Corporation Common Stock

TABLE OF CONTENTS  Filed Pursuant to Rule 424(b)(5)  Registration No. 333-277448 PROSPECTUS SUPPLEMENT (To Prospectus dated February 28, 2024) 9,774,436 Shares Pinnacle West Capital Corporation Common Stock Pinnacle West Capital Corporation is entering into separate forward sale agreements with Mizuho Markets Americas LLC and Wells Fargo Bank, National Association, which are referred to as the for

Calculation of Filing Fee Tables 424(b)(5) (Form Type) Pinnacle West Capital Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities

Exhibit 107 Calculation of Filing Fee Tables 424(b)(5) (Form Type) Pinnacle West Capital Corporation (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered(1) Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price(1)(2) Fee Rate Amount of Registration Fee Newly Registered Securities Fees to be Paid Equity Common Stock, no par value 457(r) 11,240,601 $66.

Pinnacle West Announces PRiCING OF A Public Offering of 9,774,436 Shares of Common Stock

Exhibit 99.1 FOR IMMEDIATE RELEASE February 29, 2024 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Page 1 of 2 Website: pinnaclewest.com Pinnacle West Announces PRiCING OF A Public Offering of 9,774,436 Shares of Common Stock PHOENIX – Pinnacle West Capital Corp. (NYSE: PNW) (“Pinnacle West”) announced today that it has priced its registered public offering o

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 29, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Resolutions of APS Board of Directors re Powers of Attorney

Exhibit 24.3 ARIZONA PUBLIC SERVICE COMPANY RESOLUTIONS FOR FILING REGISTRATION STATEMENTS FOR THE FEBRUARY 21, 2024 BOARD OF DIRECTORS MEETING RESOLVED, that each of the proper officers of Arizona Public Service Company (the “Company”), acting on its behalf, is hereby authorized to prepare, execute and file with the Securities and Exchange Commission an appropriate registration statement or regis

Resolutions of Pinnacle West Board of Directors re Powers of Attorney

Exhibit 24.2 PINNACLE WEST CAPITAL CORPORATION RESOLUTIONS FOR FILING REGISTRATION STATEMENTS FOR THE FEBRUARY 21, 2024 BOARD OF DIRECTORS MEETING RESOLVED, that each of the proper officers of Pinnacle West Capital Corporation (the “Company”), acting on its behalf, is hereby authorized to prepare, execute and file with the Securities and Exchange Commission an appropriate registration statement or

As filed with the Securities and Exchange Commission on February 28, 2024

TABLE OF CONTENTS As filed with the Securities and Exchange Commission on February 28, 2024 Registration Nos.

SUBJECT TO COMPLETION, DATED FEBRUARY 28, 2024

TABLE OF CONTENTS The information in this preliminary prospectus supplement is not complete and may be changed.

Form T-1 Statement of Eligibility under the Trust Indenture Act of 1939, as amended, for the Indenture dated as of January 15, 1998 relating to the APS Senior Unsecured Debt Securities

Exhibit 25.3 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO SECTION 305(b)(2) ¨ THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. (Exact name of trustee as specified in its charter) (Ju

Form T-1 Statement of Eligibility under the Trust Indenture Act of 1939, as amended, for the Indenture dated as of December 1, 2000 relating to the Pinnacle West Senior Unsecured Debt Securities

Exhibit 25.1 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO SECTION 305(b)(2) ¨ THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. (Exact name of trustee as specified in its charter) (Ju

Form T-1 Statement of Eligibility under the Trust Indenture Act of 1939, as amended, for the Indenture dated as of December 1, 2000 relating to the Pinnacle West Subordinated Unsecured Debt Securities

Exhibit 25.2 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM T-1 STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939 OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO SECTION 305(b)(2) ¨ THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. (Exact name of trustee as specified in its charter) (Ju

Opinion of Pillsbury Winthrop Shaw Pittman LLP for APS Unsecured Debt Securities

Exhibit 5.4 Pillsbury Winthrop Shaw Pittman LLP 31 West 52nd Street | New York, NY 10019-6131 | tel 212.858.1000 | fax 212.858.1500 February 24, 2024 Arizona Public Service Company 400 North Fifth Street, PO Box 53999 Phoenix, Arizona 85072-3999 Ladies and Gentlemen: We will be acting as counsel to any underwriters, dealers, purchasers or agents in connection with the offer and sale, from time to

Opinion of Robert E. Smith, APS Executive Vice President, General Counsel, and Chief Development Officer for APS Unsecured Debt Securities

Exhibit 5.3 February 28, 2024 Arizona Public Service Company 400 North Fifth Street Phoenix, Arizona 85004 Ladies and Gentlemen: I have supervised lawyers who have acted as in-house counsel for Arizona Public Service Company, an Arizona corporation (the “Company”), in connection with the Company’s preparation and filing with the Securities and Exchange Commission (the “Commission”) of a registrati

Filing Fee Table

Exhibit 107 Calculation of Filing Fee Table Form S-3 (Form Type) Pinnacle West Capital Corporation (Exact Name of Registrant as Specified in its Charter) Arizona Public Service Company (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price

ARS

PINNACLE WEST CAPITAL CORPORATION 2023 ANNUAL REPORT DELIVERING ON OUR PROMISE1 2 25% 0% 50% 75% 100% 2020 2019 2021 2023 2022 $ 1 $ 2 $ 3 $ 4 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 ~5% CAGR APS Customer Satisfaction Ranking Employee Engagement Strong Dividend Track Record Annualized Dividends per Share Arizona Top-Ranking Corporate Philanthropy and Volunteer Programs Delivering on Our Promise to.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact Name of Each Regist

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): February 27, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Renewed, Reliable and Resilient Fourth-Quarter and Full-Year 2023 Financial Results, and Future Outlook February 27, 2024 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnin

Renewed, Reliable and Resilient Fourth-Quarter and Full-Year 2023 Financial Results, and Future Outlook February 27, 2024 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Policy Relating to Recovery of Erroneously Awarded Compensation

Exhibit 97 PINNACLE WEST CAPITAL CORPORATION CLAWBACK POLICY Recoupment of Incentive-Based Compensation It is the policy of Pinnacle West Capital Corporation (the “Company”) that, in the event the Company is required to prepare an accounting restatement of the Company’s financial statements due to material non-compliance with any financial reporting requirement under the federal securities laws (i

Subsidiaries of Pinnacle West

Exhibit 21.1 SUBSIDIARIES LIST Arizona Public Service Company *All other subsidiaries of Pinnacle West Capital Corporation and all subsidiaries of Arizona Public Service Company have been omitted as they do not constitute significant subsidiaries within the meaning of Rule 1-02(w) of Regulation S-X.

PINNACLE WEST REPORTS 2023 FULL-YEAR AND FOURTH-QUARTER RESULTS, SHARES 2024 FINANCIAL OUTLOOK

FOR IMMEDIATE RELEASE February 27, 2024 Media Contact: Alan Bunnell (602) 250-3376 Analyst Contacts: Amanda Ho (602) 250-3334 Website: pinnaclewest.

Description of Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934

Exhibit 4.9 DESCRIPTION OF THE REGISTRANTS’ SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 Pinnacle West Capital Corporation (“Pinnacle West”) The following description of Pinnacle West’s securities registered pursuant to Section 12 of the Securities Exchange Act of 1934 is a summary and does not purport to be complete. The description is subject to, and qualif

PNW / Pinnacle West Capital Corporation / LAZARD ASSET MANAGEMENT LLC Passive Investment

SC 13G/A 1 PINNACLEWESTCAPITALCORP.htm SCHEDULE 13G/A CUSIP No: 723484101 1) NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON: Lazard Asset Management LLC 2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) o (b) x 3) SEC USE ONLY 4) CITIZENSHIP OR PLACE OF ORGANIZATION: Delaware NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH: 5) SOLE VOTING POWER:

PNW / Pinnacle West Capital Corporation / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv0113-pinnaclewestcapitalco.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 14)* Name of issuer: Pinnacle West Capital Corp Title of Class of Securities: Common Stock CUSIP Number: 723484101 Date of Event Which Requires Filing of this Statement: December 29, 2023 Check the appropriate bo

PNW / Pinnacle West Capital Corporation / BARROW HANLEY MEWHINNEY & STRAUSS LLC - SCHEDULE 13G Passive Investment

SC 13G 1 pnw13g02132024.htm SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Pinnacle West Capital Corp (Name of Issuer) Common Stock (Title of Class of Securities) 723484101 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Check appropriate box to de

PNW / Pinnacle West Capital Corporation / Capital Research Global Investors - SEC SCHEDULE 13G Passive Investment

SC 13G 1 SEC13GFiling.htm SEC SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Pinnacle West Capital Corp. (Name of Issuer) Common Stock (Title of Class of Securities) 723484101 (CUSIP Number) December 29, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate bo

PNW / Pinnacle West Capital Corporation / STATE STREET CORP Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G UNDER THE SECURITIES EXCHANGE ACT OF 1934 AMENDED FILING PINNACLE WEST CAPITAL CORP (NAME OF ISSUER) COMMON STOCK (TITLE OF CLASS OF SECURITIES) 723484101 (CUSIP NUMBER) 12/31/2023 (DATE OF EVENT WHICH REQUIRES FILING OF THIS STATEMENT) CHECK THE APPROPRIATE BOX TO DESIGNATE THE RULE PURSUANT TO WHICH THIS SCHEDUL

PNW / Pinnacle West Capital Corporation / BlackRock Inc. Passive Investment

SC 13G/A 1 us7234841010012524.txt us7234841010012524.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 15) PINNACLE WEST CAPITAL CORP - (Name of Issuer) Common Stock - (Title of Class of Securities) 723484101 - (CUSIP Number) December 31, 2023 - (Date of Event Which Requires Filing of this Statement) Check the approp

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): January 10, 2024 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

January Investor Meetings January 2024 Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forwa

January Investor Meetings January 2024 Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): December 1, 2023 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

December Investor Meetings December 2023 Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These for

December Investor Meetings December 2023 Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

EEI Investor Meetings November 12-14 2023 Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These fo

EEI Investor Meetings November 12-14 2023 Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 9, 2023 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): November 2, 2023 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

PINNACLE WEST REPORTS 2023 THIRD-QUARTER RESULTS

FOR IMMEDIATE RELEASE November 2, 2023 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Website: pinnaclewest.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Exact Name of Ea

POWERING GROWTH DELIVERING VALUE Third Quarter 2023 Results November 2, 2023 1 Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and

POWERING GROWTH DELIVERING VALUE Third Quarter 2023 Results November 2, 2023 1 Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and f inancial outlook and goals.

Investor Presentation September 2023 Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals. These forward

Investor Presentation September 2023 Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): September 5, 2023 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

PINNACLE WEST REPORTS LOWER 2023 SECOND-QUARTER FINANCIAL RESULTS

FOR IMMEDIATE RELEASE August 3, 2023 Media Contact: Analyst Contact: Alan Bunnell (602) 250-3376 Amanda Ho (602) 250-3334 Website: pinnaclewest.

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): August 3, 2023 Commission File Number Exact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone Number IRS Employer Identification No.

POWERING GROWTH DELIVERING VALUE Second Quarter 2023 Results August 3, 2023 1 Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and f

a2q2023earningsdeckfinal POWERING GROWTH DELIVERING VALUE Second Quarter 2023 Results August 3, 2023 1 Forward Looking Statements 2 This presentation contains forward-looking statements based on current expectations, including statements regarding our earnings guidance and financial outlook and goals.