Columbia Banking (NASDAQ: COLB) EVP exercises 2,506 RSUs, 1,215 shares withheld for taxes

Rhea-AI Filing Summary

COLUMBIA BANKING SYSTEM, INC. executive Drew K. Anderson, EVP Chief Admin Officer, exercised 2,506 Restricted Stock Units into the same number of common shares on March 13, 2026. The RSUs convert to common stock on a one-for-one basis.

To cover tax obligations, 1,215 common shares were withheld at $26.23 per share, a non-market disposition rather than an open-market sale. After these transactions, Anderson directly holds 21,969 common shares. A prior grant of 7,518 RSUs vests in three annual installments beginning on March 13, 2026.

Insider Trade Summary

2,506 shares exercised/converted

Mixed 3 txns

Insider Anderson Drew K

Role EVP Chief Admin Officer

Type	Security	Shares	Price	Value
Exercise	Restricted Stock Unit	2,506	$0.00	--
Exercise	Common Stock	2,506	$26.23	$66K
Tax Withholding	Common Stock	1,215	$26.23	$32K

Holdings After Transaction: Restricted Stock Unit — 50,607 shares (Direct); Common Stock — 23,184 shares (Direct)

Footnotes (1)

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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^*

Anderson Drew K

(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 Chief Admin Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/13/2026

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	03/13/2026		M		2,506	A	$26.23	23,184	D
Common Stock	03/13/2026		F		1,215	D	$26.23	21,969	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
Restricted Stock Unit	(1)	03/13/2026		M			2,506	(1)	(1)	Common Stock	2,506	$0	50,607	D

Explanation of Responses:

1. Restricted Stock Units convert into common stock on a one-for-one basis. On February 25, 2025, the reporting person was granted 7,518 Restricted Stock Units, which vest in three annual installments beginning on March 13, 2026.

Remarks:

	/s/ Andrea M. Newburn, Attorney-in-fact	03/17/2026
	** 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 did COLB executive Drew K. Anderson report in this Form 4?

Drew K. Anderson reported exercising 2,506 Restricted Stock Units into common shares. He then had 1,215 shares withheld to satisfy tax obligations, leaving him with 21,969 common shares held directly after the transactions.

How many Columbia Banking System (COLB) RSUs did Drew Anderson exercise?

Drew Anderson exercised 2,506 Restricted Stock Units, converting them into 2,506 common shares on a one-for-one basis. The exercise occurred on March 13, 2026, as part of his previously granted equity compensation.

Were any of Drew Anderson’s COLB shares sold in the market?

No open-market sales were reported. Instead, 1,215 common shares were withheld at $26.23 per share to cover tax liabilities associated with the RSU exercise, a standard non-market tax-withholding disposition.

How many COLB common shares does Drew Anderson hold after these transactions?

Following the RSU exercise and tax withholding, Drew Anderson directly holds 21,969 shares of Columbia Banking System common stock. This figure reflects his updated post-transaction ownership position as disclosed in the Form 4.

What does the RSU grant footnote disclose for COLB’s Drew Anderson?

The footnote states Anderson was granted 7,518 Restricted Stock Units on February 25, 2025. These RSUs vest in three equal annual installments, beginning on March 13, 2026, providing a staggered equity compensation schedule.

What transaction codes appear in Drew Anderson’s COLB Form 4 and what do they mean?

The filing shows code M for the exercise or conversion of a derivative security, when RSUs became common shares, and code F for shares withheld to pay tax liabilities, indicating a tax-withholding disposition rather than a market sale.