Columbia Banking (COLB) EVP updates share holdings after RSU performance and tax events

Rhea-AI Filing Summary

Columbia Banking System executive Kumi Yamamoto Baruffi reported routine stock adjustments tied to performance awards and taxes. On January 20, 2026, 632 shares of common stock were forfeited at $0 under performance-based restricted stock units granted on February 21, 2023, after a total shareholder return target was not achieved at the target level. The same day, 1,508 shares were withheld at $28.35 per share to cover tax obligations from the vesting of restricted stock units. Following these transactions, the executive directly owned 52,123 shares of Columbia Banking common stock.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider BARUFFI KUMI YAMAMOTO

Role EVP General Counsel, Corp Sec

Type	Security	Shares	Price	Value
Disposition	Common Stock	632	$0.00	--
Tax Withholding	Common Stock	1,508	$28.35	$43K

Holdings After Transaction: Common Stock — 53,631 shares (Direct)

Footnotes (1)

1. Shares forfeited pursuant to the terms of the performance restricted stock units granted on February 21, 2023 and reported on the reporting person's Form 4 filed on February 21, 2023 (in accordance with Rule 16b-3(e)) due to the issuer's total shareholder return performance target not being met at target. Represents withholding of shares of common stock to satisfy the reporting person's tax withholding obligations in connection with the vesting of previously issued restricted stock units.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

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
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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 for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

BARUFFI KUMI YAMAMOTO

(Last) (First) (Middle)

C/O COLUMBIA BANKING SYSTEM, INC.

1301 A STREET

(Street)

TACOMA WA 98402

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
COLUMBIA BANKING SYSTEM, INC. [ COLB ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP General Counsel, Corp Sec

3. Date of Earliest Transaction (Month/Day/Year)
01/20/2026

4. If Amendment, Date of 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

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	01/20/2026		D		632(1)	D	$0	53,631	D
Common Stock	01/20/2026		F		1,508(2)	D	$28.35	52,123	D

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 Securities Underlying Derivative Security (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: 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

Explanation of Responses:

1. Shares forfeited pursuant to the terms of the performance restricted stock units granted on February 21, 2023 and reported on the reporting person's Form 4 filed on February 21, 2023 (in accordance with Rule 16b-3(e)) due to the issuer's total shareholder return performance target not being met at target.

2. Represents withholding of shares of common stock to satisfy the reporting person's tax withholding obligations in connection with the vesting of previously issued restricted stock units.

Remarks:

	/s/ Andrea M. Newburn, Attorney-in-fact	01/22/2026
	** Signature of Reporting Person	Date
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.

FAQ

What insider activity did COLB report for EVP General Counsel Kumi Yamamoto Baruffi?

The executive reported two non-derivative transactions in Columbia Banking common stock on January 20, 2026: a forfeiture of 632 shares and tax withholding of 1,508 shares tied to equity awards.

Why were 632 COLB shares forfeited by the executive?

The 632 shares were forfeited under performance restricted stock units granted on February 21, 2023 because Columbia Banking’s total shareholder return performance target was not met at target.

Why were 1,508 COLB shares withheld at $28.35 per share?

The 1,508 shares of Columbia Banking common stock were withheld at $28.35 per share to satisfy the executive’s tax withholding obligations related to vesting of previously issued restricted stock units.

How many COLB shares does the executive own after these transactions?

After the January 20, 2026 transactions, EVP General Counsel Kumi Yamamoto Baruffi directly beneficially owned 52,123 shares of Columbia Banking common stock.

Are these COLB Form 4 transactions open-market sales?

No. The filing describes a forfeiture of 632 shares due to performance conditions not being met and a 1,508 share withholding to cover taxes on vesting restricted stock units, rather than open-market sales.

Does the COLB Form 4 show any derivative securities for the executive?

Table II for derivative securities in this Form 4 does not list any derivative stock option or similar transactions for the reporting executive in the provided excerpt.