Pinnacle West Capital 8-K 2026-08-10

Filed 2026-08-13. 1 sections, 6K characters. Original on sec.gov · Markdown · JSON

Form 8-K

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 10, 2026
Commission File NumberExact Name of Each Registrant as specified in its charter; State of Incorporation; Address; and Telephone NumberIRS Employer Identification No.
1-8962PINNACLE WEST CAPITAL CORPORATION86-0512431
(an Arizona corporation)
400 North Fifth Street, P.O. Box 53999
Phoenix Arizona85072-3999
(602) 250-1000
1-4473ARIZONA PUBLIC SERVICE COMPANY86-0011170
(an Arizona corporation)
400 North Fifth Street, P.O. Box 53999
Phoenix Arizona85072-3999
(602) 250-1000

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
¨Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
¨Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
¨Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each classTrading Symbol(s)Name of each exchange on which registered
Common StockPNWThe New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2).

Emerging growth company¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

This combined Form 8-K is separately filed or furnished by Pinnacle West Capital Corporation and Arizona Public Service Company. Each registrant is filing or furnishing on its own behalf all of the information contained in this Form 8-K that relates to such registrant and, where required, its subsidiaries. Except as stated in the preceding sentence, neither registrant is filing or furnishing any information that does not relate to such registrant, and therefore makes no representation as to any such information.

Co-Registrant CIK0000007286
Co-Registrant Amendment Flagfalse
Co-Registrant Form Type8-K
Co-Registrant Document Period EndDate2026-08-10
Co-Registrant Written Communicationsfalse
Co-Registrant Solicitating Materialsfalse
Co-Registrant PreCommencement Tender Offerfalse
Co-Registrant PreCommencement Issuer Tender Offerfalse
Co-Registrant Emerging growth companyfalse
Item 9.01.Financial Statements and Exhibits.
(d)Exhibits.

The registrants hereby file the following Exhibits to Registration Statement on Form S-3 (No. 333-277448 and No. 333-277448-01, which became effective on February 28, 2024).

Exhibit No.DescriptionPreviously Filed as ExhibitDate Filed
1.1Underwriting Agreement dated August 10, 2026, in connection with the offering of $100,000,000 of 5.50% Notes due 2035 and $600,000,000 of 6.25% Notes due 2056
4.1Ninth Supplemental Indenture dated as of August 15, 2005, relating to the issuance of 5.50% Notes due 20354.1 to APS August 22, 2005 Form 8-K Report8/22/2005
4.2Thirty-Fourth Supplemental Indenture relating to the issuance of $600,000,000 of 6.25% Notes due 2056
4.3Note of 5.50% Notes due 20354.2 to APS August 22, 2005 Form 8-K Report8/22/2005
4.4Note of 6.25% Notes due 2056
5.1Opinion of Shirley A. Baum, Senior Vice President, General Counsel and Corporate Secretary
99.1Information relating to Item 14 of the Registration Statement on Form S-3 (No. 333-277448-01)
104104 Cover Page Interactive Data File (embedded within the Inline XBRL document)

Pursuant to the requirements of the Securities Exchange Act of 1934, each registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

PINNACLE WEST CAPITAL CORPORATION
(Registrant)
Dated: August 13, 2026By: /s/ Andrew Cooper
Andrew Cooper
Senior Vice President and Chief Financial Officer
ARIZONA PUBLIC SERVICE COMPANY
(Registrant)
Dated: August 13, 2026By: /s/ Andrew Cooper
Andrew Cooper
Senior Vice President and Chief Financial Officer