FIRST INTERSTATE BANCSYSTEM INC — Director's Dealing 2025

Oct 9, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: FIRST INTERSTATE BANCSYSTEM INC (FIBK)
CIK: 0000860413
Period of Report: 2025-10-09

Reporting Person: Scott Jonathan R (10% Owner)
Reporting Person: Jonathan Scott as Trustee of the Jonathan R Scott Trust Dated as of 4/21/04 (10% Owner)
Reporting Person: Harrison William Scott Trust (10% Owner)
Reporting Person: Harper Grace Scott Trust (10% Owner)
Reporting Person: Holland Elizabeth Scott Trust (10% Owner)
Reporting Person: IXL Ltd Liability Co (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-10-09	Common Stock	S	685	$31.66	Disposed	952824	Indirect

Footnotes

F1: The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $31.52 to $31.76. The reporting person undertakes to provide to First Interstate BancSystem, Inc., any security holder of First Interstate BancSystem, Inc., or the staff of the Securities and Exchange Commission, upon, request, the full information regarding the number of shares sold at each separate price within the ranges set forth above.

F2: Composed of 589,086 shares held of record by Jonathan Scott as Trustee of the Jonathan R Scott Trust Dated as of 4/21/04, 209,678 shares held of record by IXL Limited Liability Company, 36,553 shares held of record by Holland Elizabeth Scott Trust, 36,553 shares held of record by Harper Grace Scott Trust, 36,554 shares held of record by Harrison William Scott Trust and 50,000 shares held of record by Jonathan Scott's spouse.

F3: As a result of certain agreements entered into by and among the reporting persons, the Issuer, and certain other stockholders of the Issuer, the reporting persons may be deemed members of a group with the other signatories thereto and may be deemed to share beneficial ownership of the securities reported herein. Each of the reporting persons disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. The reporting persons expect to file future Forms 4 and 5, if any, together with Jonathan R. Scott with the indication of direct or indirect ownership in Table I and Table II being made from Jonathan R. Scott's perspective. The nature of beneficial ownership is described in detail by footnote for all reporting persons.