Sec Form 4 Filing - RICE TOM @ PACIFIC PREMIER BANCORP INC - 2025-08-31

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 RICE TOM 2. Issuer Name and Ticker or Trading Symbol PACIFIC PREMIER BANCORP INC [ PPBI] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) SEVP/ Chief Innovation Officer (Last) (First) (Middle) 17901 VON KARMAN AVE., SUITE 1200 3. Date of Earliest Transaction (MM/DD/YY) 08/31/2025 (Street) IRVINE, CA92614 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 PPBI Common Stock 08/31/2025 D 30,657 D 0 D PPBI Common Stock 08/31/2025 D 82,487 D 0 I By The Rice Family Trust

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 PPBI Restricted Stock Unit ( 3 ) 08/31/2025 D( 3 )( 4 ) 16,092 ( 3 ) ( 5 ) PPBI Common Stock 16,092 $ 0 0 D PPBI Restricted Stock Unit ( 3 ) 08/31/2025 D( 3 )( 6 ) 16,136 ( 3 ) ( 5 ) PPBI Common Stock 16,136 $ 0 0 D PPBI Restricted Stock Unit ( 3 ) 08/31/2025 D( 3 )( 7 ) 16,802 ( 3 ) ( 5 ) PPBI Common Stock 16,802 $ 0 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other RICE TOM 17901 VON KARMAN AVE., SUITE 1200 IRVINE, CA92614 SEVP/ Chief Innovation Officer Signatures /s/ Tom Rice 09/03/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Disposed of in connection with the Agreement and Plan of Merger (the "Merger Agreement"), dated April 23, 2025, by and among Columbia Banking System, Inc. ("Columbia"), Pacific Premier Bancorp, Inc. (the "Issuer") and Balboa Merger Sub, Inc., pursuant to which the Issuer was merged with and into Columbia on August 31, 2025 (the "Effective Time"). Pursuant to the Merger Agreement, as of the Effective Time, each share of the Issuer's common stock outstanding immediately prior to the Effective Time was converted into the right to receive 0.9150 of a share of Columbia common stock, with cash (without interest) paid in lieu of fractional shares, if applicable (the "Exchange Ratio"). ( 2 )Includes 30,657 shares of restricted stock ("Issuer RSA"). Pursuant to the Merger Agreement, at the Effective Time, each Issuer RSA was assumed and converted into a restricted stock award in respect of shares of Columbia common stock based on the Exchange Ratio and subject to the same terms and conditions as were applicable to the Issuer RSA immediately prior to the Effective Time. ( 3 )Each Restricted Stock Unit ("Issuer RSU") represents the right to receive one share of common stock. Pursuant to the Merger Agreement, at the Effective Time, each Issuer RSU was assumed and converted into a restricted stock unit award in respect of Columbia common stock ("Columbia RSU"), with the number of shares of Columbia common stock subject to each such Columbia RSU award equal to the product of (i) the number of shares of Issuer common stock subject to such Issuer RSU award immediately prior to the Effective Time based on target performance multiplied by (ii) the Exchange Ratio. Except as specifically provided in the Merger Agreement, each such Columbia RSU award will continue to be subject to the same terms and conditions as were applicable to the applicable Issuer RSU immediately prior to the Effective Time. ( 4 )Includes approximately 2,041 dividend equivalent rights accrued between May 2023 to August 2025. Each dividend equivalent right is the economic equivalent of one share of common stock. ( 5 )Not applicable. ( 6 )Includes approximately 483 dividend equivalent rights accrued between May 2025 to August 2025. Each dividend equivalent right is the economic equivalent of one share of common stock. ( 7 )Includes approximately 1,322 dividend equivalent rights accrued between May 2024 to August 2025. Each dividend equivalent right is the economic equivalent of one share of common stock.

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.