Form 4 Filing by Kristina Robbins

Kristina Robbins, EVP, Chief Operations Officer of FIRST INTERSTATE BANCSYSTEM INC (FIBK), acquired 4,044 shares of Common Stock on March 15, 2026, at a price of $33.13 per share. This transaction, reported on Form 4, resulted in a post-transaction holding of 20,128 shares. The shares were acquired upon vesting of restricted stock units granted under the company's 2023 Equity and Incentive Plan. These units vest in three equal annual installments starting March 15, 2027, contingent upon continued employment. The filing was signed by Kirk D. Jensen as attorney in fact for Robbins on March 17, 2026.