Sec Form 4 Filing - Mountain Paul J @ PINNACLE WEST CAPITAL CORP - 2024-02-20

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Mountain Paul J 2. Issuer Name and Ticker or Trading Symbol PINNACLE WEST CAPITAL CORP [ PNW] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) VP, Finance and Treasurer (Last) (First) (Middle) 400 N 5TH ST 3. Date of Earliest Transaction (MM/DD/YY) 02/20/2024 (Street) PHOENIX, AZ85004 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 02/20/2024 A 362 ( 1 ) A $ 0 ( 1 ) 362 D Common Stock 02/20/2024 F( 2 ) 169 D $ 69.1 193 D Common Stock 02/20/2024 A 58 ( 3 ) A $ 0 ( 3 ) 251 D Common Stock 02/20/2024 F( 2 ) 28 D $ 69.1 223 D Common Stock 02/20/2024 M 148 ( 4 ) A $ 0 ( 4 ) 371 D Common Stock 02/20/2024 F( 2 ) 70 D $ 69.1 301 D Common Stock 02/20/2024 M 144 ( 4 ) A $ 0 ( 4 ) 445 D Common Stock 02/20/2024 D 144 D $ 69.1 301 D Common Stock 02/20/2024 M 144 ( 4 ) A $ 0 ( 4 ) 445 D Common Stock 02/20/2024 F( 2 ) 68 D $ 69.1 377 D Common Stock 02/20/2024 M 45 ( 5 ) A $ 0 ( 5 ) 422 D Common Stock 02/20/2024 D( 6 ) 2 D $ 69.1 420 D Common Stock 02/20/2024 F( 2 ) 21 D $ 69.1 399 D Common Stock 02/20/2024 M 451 ( 5 ) A $ 0 ( 5 ) 850 D Common Stock 02/20/2024 D( 6 ) 42 D $ 69.1 808 D Common Stock 02/20/2024 F( 2 ) 191 D $ 69.1 617 D Common Stock 02/20/2024 M 486 ( 5 ) A $ 0 ( 5 ) 1,103 D Common Stock 02/20/2024 D( 6 ) 22 D $ 69.1 1,081 D Common Stock 02/20/2024 F( 2 ) 211 D $ 69.1 870 D Common Stock 02/20/2024 A 55 ( 7 ) A $ 0 ( 7 ) 925 D Common Stock 02/20/2024 F( 2 ) 23 D $ 69.1 902 D Common Stock 02/20/2024 G( 8 ) 902 D $ 0 ( 8 ) 0 D Common Stock 02/20/2024 G( 8 ) 902 A $ 0 ( 8 ) 4,119 ( 9 ) I by Trust Common Stock 278 I by 401(k)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Restricted Stock Units ( 4 ) 02/20/2024 M 148 ( 10 ) ( 10 ) Common Stock 148 $ 0 ( 4 ) 0 D Restricted Stock Units ( 4 ) 02/20/2024 M 288 ( 11 ) ( 11 ) Common Stock 288 $ 0 ( 4 ) 288 D Restricted Stock Units ( 5 ) 02/20/2024 M 45 ( 12 ) ( 13 ) ( 13 ) Common Stock 45 $ 0 ( 5 ) 93 ( 14 ) D Restricted Stock Units ( 5 ) 02/20/2024 M 451 ( 15 ) ( 16 ) ( 16 ) Common Stock 451 $ 0 ( 5 ) 895 ( 17 ) D Restricted Stock Units ( 5 ) 02/20/2024 M 486 ( 18 ) ( 19 ) ( 19 ) Common Stock 486 $ 0 ( 5 ) 1,456 ( 20 ) D Restricted Stock Units ( 5 ) 02/20/2024 A 2,172 ( 21 ) ( 21 ) Common Stock 2,172 ( 5 ) 2,172 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Mountain Paul J 400 N 5TH ST PHOENIX, AZ85004 VP, Finance and Treasurer Signatures /s/ Diane Wood, Attorney-in-Fact 02/22/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Shares acquired upon the vesting of a portion of the performance shares granted in 2021 that were tied to the total shareholder return performance metric. ( 2 )Shares retained by the Company for the purpose of meeting tax withholding requirements. The recipient retained all other shares. ( 3 )Represents shares of common stock received by the individual in settlement of dividend rights that vested in connection with the performance shares that vested on February 20, 2024. ( 4 )Each Restricted Stock Unit represents a contingent right to receive the economic equivalent of one share of the Company's common stock. The Restricted Stock Units will be settled, at the reporting person's election, in 100% shares of common stock, 50% in common stock and 50% in cash, or 100% in cash. ( 5 )Each Restricted Stock Unit represents a contingent right to receive the economic equivalent of one share of the Company's common stock. The Restricted Stock Units will be settled either in 100% shares of common stock or 100% in cash with respect to Restricted Stock Units received in connection with the settlement of dividend equivalent rights. ( 6 )Represents the cash settlement of Restricted Stock Units received in connection with the settlement of dividend equivalent rights. ( 7 )Represents shares of common stock received by the individual in settlement of dividend rights granted in connection with the 2020 and 2021 Restricted Stock Unit grants. ( 8 )The reporting person gifted the shares received on February 20, 2024 to a revocable family trust. ( 9 )This total includes 123 shares that were acquired over time under a dividend reinvestment program and that were not reported on prior Form 4's. ( 10 )The Restricted Stock Unit award was granted and was effective in February 2020, and vests in four equal annual installments beginning on February 20, 2021. ( 11 )The Restricted Stock Units award was granted and was effective in February 2021, and vests in four equal, annual installments beginning on February 20, 2022. ( 12 )The number of derivative securities in Column 5 includes 2 vested Restricted Stock Units received in connection with the settlement of dividend equivalent rights. Dividend equivalent rights accrue with respect to these Restricted Stock Units when and as cash dividends are paid on the Company's common stock. ( 13 )The Restricted Stock Unit award was granted and was effective in May 20, 2022 and vests in four equal, annual installments beginning on February 20, 2023. ( 14 )Includes 7 Restricted Stock Units received in connection with the settlement of dividend equivalent rights. ( 15 )The number of derivative securities in Column 5 includes 42 vested Restricted Stock Units received in connection with the settlement of dividend equivalent rights. Dividend equivalent rights accrue with respect to these Restricted Stock Units when and as cash dividends are paid on the Company's common stock. ( 16 )The Restricted Stock Unit award was granted and was effective in February 2022, and vests in four equal annual installments beginning on February 20, 2023. ( 17 )Includes 77 Restricted Stock Units received in connection with the settlement of dividend equivalent rights. ( 18 )The number of derivative securities in Column 5 includes 22 vested Restricted Stock Units received in connection with the settlement of dividend equivalent rights. Dividend equivalent rights accrue with respect to these Restricted Stock Units when and as cash dividends are paid on the Company's common stock. ( 19 )The Restricted Stock Unit award was granted and was effective in February 2023, and vests in four equal annual installments beginning on February 20, 2024. ( 20 )Includes 64 Restricted Stock Units received in connection with the settlement of dividend equivalent rights. ( 21 )The Restricted Stock Units award was granted and was effective in February 2024, and vests in four equal, annual installments beginning on February 20, 2025.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.