COLUMBIA BANKING SYSTEM, INC. — Form 8-K

Tory Nixon, Co-President of Columbia Bank and Senior EVP of CBSI, will retire effective July 1, 2027 (or mutually agreed date). Through that date, Nixon continues in current role and is eligible for a 2027 equity grant at or above 2026 grant levels. After July 1, 2027, Nixon becomes a full-time senior advisor through December 31, 2027, receiving base salary continuation, health benefits, and equity vesting; the retirement qualifies as a 'qualifying retirement' for equity awards. Non-disparagement and restrictive covenants apply, with full whistleblower protections preserved.