SEC Filing Summary - Form 3 Filing for Lee Jeffery D.

This filing is an initial report on Form 3 for Lee Jeffery D., Chief Operations Officer of FIRST INTERSTATE BANCSYSTEM INC. The report indicates that Lee Jeffery D. did not beneficially own any shares of the company's Common Stock at the time of filing. The filing includes a Power of Attorney (Exhibit 24) authorizing Brian M. Murphy as attorney-in-fact for the reporting person. The ownership details provided are based on information available as of September 14, 2026.