BARUFFI KUMI YAMAMOTO 4/A

What Happened

• Kumi Yamamoto Baruffi, EVP, General Counsel and Corporate Secretary of Columbia Banking System, had 937 shares withheld by the issuer to satisfy tax obligations in connection with equity award vesting. The withheld shares were valued at $26.23 each for a total of $24,578. The underlying transaction date was March 13, 2026.

Key Details

• Transaction date and price: March 13, 2026 — 937 shares withheld at $26.23/share (total ~$24,578).
• Transaction type: Tax withholding related to award vesting (SEC Form 4 transaction code F).
• Filing: This is an amended Form 4 (filed Mar 20, 2026) correcting the transaction code from S (sale) to F (withholding). The original Form 4 was filed Mar 17, 2026.
• Shares owned after transaction: Not specified in the provided filing excerpt.
• Timeliness: The initial Form 4 was filed four days after the transaction (Mar 17); this amendment was filed Mar 20. Insiders normally must file within two business days; the amendment corrects the transaction code but does not change the original filing date.

Context

• This was not an open-market sale by the insider but a routine issuer share-withholding to cover tax liabilities when restricted stock or other equity awards vest. Such withholdings are administrative and do not necessarily indicate a change in the insider’s view of the company.