Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

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

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(Print or Type Responses)

1. Name and Address of Reporting Person * Splaine Thomas Jr 2. Issuer Name and Ticker or Trading Symbol Columbia Financial, Inc. [CLBK] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) EVP, CFO (Last) (First) (Middle) 19-01 ROUTE 208 NORTH 3. Date of Earliest Transaction (Month/Day/Year) 03/02/2026 (Street) FAIR LAWN, NJ 07410 4. If Amendment, Date Original Filed (Month/Day/Year) 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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 03/02/2026 A 9,475 A $ 0 9,475 I Stock Award II(1) Common Stock 1,177 I By Stock Award(2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

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 (Month/Day/Year)

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

Stock Options (right to buy)

$18.28

03/02/2026

A

16,098

03/02/2027(3)

03/02/2036

Common Stock

16,098

$ 0

16,098

D

Stock Options (right to buy)

$16.23

03/03/2026(4)

03/03/2035

Common Stock

9,176

9,176

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Splaine Thomas Jr 19-01 ROUTE 208 NORTH FAIR LAWN, NJ 07410			EVP, CFO

Signatures

/s/ Dennis E. Gibney, Power of Attorney		03/04/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Stock Awards granted pursuant to the Columbia Financial, Inc. 2019 Equity Incentive plan, which vest upon achievement of certain specified performance-based vesting criteria, which if achieved, such Awards would vest three years after the date of the Award on March 2, 2029.
(2)	Stock Awards granted pursuant to the Columbia Financial, Inc. 2019 Equity Incentive Plan which vest in three approximately equal annual installments commencing on March 3, 2026.
(3)	Stock Options granted pursuant to the Columbia Financial, Inc. 2019 Equity Incentive Plan vest in three approximately equal annual installments commencing on March 2, 2027.
(4)	Stock Options granted pursuant to the Columbia Financial, Inc. 2019 Equity Incentive Plan vest in three approximately equal annual installments commencing on March 3, 2026.

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