Columbia Banking System (COLB) Proxy Filing summary

Executive summary

• Annual meeting scheduled for May 15, 2025, at 10:00 AM PDT, accessible virtually for shareholders.

• Shareholders are encouraged to review proxy materials and vote by May 14, 2025, for common shares and May 13, 2025, for employee benefit plan shares.

Voting matters and shareholder proposals

• Election of eleven directors is on the agenda, with all nominees recommended for approval.

• Advisory vote on executive compensation is proposed, with board recommending approval.

• Ratification of Deloitte & Touche LLP as independent auditor for fiscal year ending December 31, 2025, is recommended.

• Proxies may vote on other business that arises during the meeting.

Board of directors and corporate governance

• Eleven director nominees are listed, including Maria M. Pope, Mark A. Finkelstein, and others.

• Board recommends voting in favor of all director nominees.