Pinnacle West (NYSE: PNW) adds exhibits for $600M 5.10% 2036 notes

Rhea-AI Filing Summary

Pinnacle West Capital Corporation and its utility subsidiary Arizona Public Service Company (APS) filed a Form 8-K to add exhibits tied to APS’s offering of $600,000,000 principal amount of 5.10% Notes due 2036 under an existing shelf registration.

An underwriting agreement, supplemental indenture, note form, legal opinion and additional information about issuance-related liabilities are included. APS estimates non-underwriting issuance and distribution expenses at $1,494,186, led by rating agency fees of $1,300,000, plus SEC fees, legal, accounting, printing and other administrative costs.

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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.
1-8962		PINNACLE WEST CAPITAL CORPORATION			86-0512431
		(an Arizona corporation)
		400 North Fifth Street, P.O. Box 53999
		Phoenix Arizona	85072-3999
		(602) 250-1000
1-4473		ARIZONA PUBLIC SERVICE COMPANY			86-0011170
		(an Arizona corporation)
		400 North Fifth Street, P.O. Box 53999
		Phoenix Arizona	85072-3999
		(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 class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock	PNW	The 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 CIK	0000007286
Co-Registrant Amendment Flag	false
Co-Registrant Form Type	8-K
Co-Registrant Document Period EndDate	2026-03-10
Co-Registrant Written Communications	false
Co-Registrant Solicitating Materials	false
Co-Registrant PreCommencement Tender Offer	false
Co-Registrant PreCommencement Issuer Tender Offer	false
Co-Registrant Emerging growth company	false

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.		Description		Previously Filed as Exhibit		Date Filed
1.1		Underwriting Agreement dated March 10, 2026, in connection with the offering of $600,000,000 of 5.10% Notes due 2036
4.1		Thirty-Third Supplemental Indenture relating to the issuance of $600,000,000 of 5.10% Notes due 2036
4.2		Note of 5.10% Notes due 2036
5.1		Opinion of Shirley A. Baum, Senior Vice President, General Counsel and Corporate Secretary
99.1		Information relating to Item 14 of the Registration Statement on Form S-3 (No. 333-277448-01)
104		104 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: March 12, 2026		By: /s/ Andrew Cooper
		Andrew Cooper
		Senior Vice President and Chief Financial Officer
		ARIZONA PUBLIC SERVICE COMPANY
		(Registrant)
Dated: March 12, 2026		By: /s/ Andrew Cooper
		Andrew Cooper
		Senior Vice President and Chief Financial Officer

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 Securities and Exchange Commission and dated March 10, 2026 are estimated to be as follows:

Securities and Exchange Commission registration fee		$	82, 686
Printing, engraving, and postage expenses		$	15,000
Legal fees and expenses		$	9,500
Accounting fees and expenses		$	75,000
Rating Agency fees		$	1,300,000
Transfer Agent and Registrar, Trustee and Depository fees and expenses		$	10,000
Blue Sky fees and expenses		$	2,000
Total		$	1,494,186

FAQ

What securities is Pinnacle West (PNW) registering in this Form 8-K?

Arizona Public Service Company is offering $600,000,000 principal amount of 5.10% Notes due 2036. The Form 8-K adds key underwriting, indenture and disclosure exhibits under APS’s existing Form S-3 shelf registration to support this long-term debt issuance.

How much will Pinnacle West (PNW) and APS spend on issuance expenses?

APS estimates non-underwriting issuance and distribution expenses of $1,494,186 for the 5.10% Notes. This total covers SEC registration fees, printing, legal and accounting costs, rating agency fees, transfer agent and trustee charges, and Blue Sky compliance expenses for the offering.

What are the largest individual expenses in APS’s $600 million notes offering?

The largest single item is rating agency fees of $1,300,000. Other estimated costs include an $82,686 SEC registration fee, $75,000 in accounting expenses, $15,000 for printing and postage, $10,000 for transfer and trustee services, and $9,500 for legal fees.

Which companies are covered by this Pinnacle West (PNW) Form 8-K?

The Form 8-K is a combined filing for Pinnacle West Capital Corporation and Arizona Public Service Company. Each registrant provides information relevant to itself under a shared shelf registration structure, with APS as the issuer of the 5.10% Notes due 2036.

What key exhibits are included with the Pinnacle West (PNW) Form 8-K?

Key exhibits include the March 10, 2026 underwriting agreement and a thirty-third supplemental indenture. The filing also attaches the form of the 5.10% Note, a legal opinion from APS’s general counsel, additional liability information, and the cover-page Inline XBRL data file.

Filing Exhibits & Attachments

9 documents

Press Releases

• EX-99.1 EXHIBIT 99.1 6.1 KB

Other Documents

• EX-1.1 EXHIBIT 1.1 183.5 KB
• EX-4.1 EXHIBIT 4.1 101.8 KB
• EX-4.2 EXHIBIT 4.2 37.0 KB
• EX-5.1 EXHIBIT 5.1 9.7 KB
• EX-101 XBRL TAXONOMY EXTENSION SCHEMA 3.4 KB
• EX-101 XBRL TAXONOMY EXTENSION DEFINITION LINKBASE 25.6 KB
• EX-101 XBRL TAXONOMY EXTENSION LABEL LINKBASE 35.0 KB
• EX-101 XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE 24.3 KB