Form 4 Filing for Shepler Christopher L.

This filing details a disposition of 222 shares of Common Stock by Christopher L. Shepler, Chief Banking Officer of FIRST INTERSTATE BANCSYSTEM INC, on September 10, 2026. The transaction, coded as "F" (fee payment), occurred at a price of $36.88 per share. This disposition was made to the issuer to cover minimum required withholding taxes due upon the vesting of unvested shares. Following this transaction, Mr. Shepler owns 13,018 shares of Common Stock directly.