FIRST INTERSTATE BANCSYSTEM INC — Director's Dealing 2025

May 30, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: FIRST INTERSTATE BANCSYSTEM INC (FIBK)
CIK: 0000860413
Period of Report: 2023-05-24

Reporting Person: Scott James R. Jr (Director, 10% Owner)
Reporting Person: First Interstate Bank TTEE for Dana S Andersson GST Exempt Trust No 1 Dtd 12/11/2020 (10% Owner)
Reporting Person: First Interstate Bank TTEE for James R Scott Jr. GST Exempt Trust No 1 Dtd 12/11/2020 (10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2023-05-24	Common Stock	A	192	—	Acquired	75579	Direct
2024-03-15	Common Stock	A	599	—	Acquired	76178	Direct
2024-03-20	Common Stock	F	23	$25.21	Disposed	76155	Direct
2025-03-15	Common Stock	A	1213	—	Acquired	77368	Direct
2025-03-17	Common Stock	F	23	$29.41	Disposed	77345	Direct
2025-03-17	Common Stock	F	69	$29.41	Disposed	75599	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	51284	Indirect

Footnotes

F1: Shares issuable upon vesting of restricted stock units granted to the reporting person pursuant to the Registrant's Equity and Incentive Plan, which units are scheduled to vest in three equal annual installments beginning on March 15, 2024, subject to the reporting person's continued employment through each applicable vesting date.

F2: Shares issuable upon vesting of restricted stock units granted to the reporting person pursuant to the Registrant's Equity and Incentive Plan, which units are scheduled to vest in three equal annual installments beginning on March 15, 2025, subject to the reporting person's continued employment through each applicable vesting date.

F3: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of restricted stock units.

F4: Shares issuable upon vesting of restricted stock units granted to the reporting person pursuant to the Registrant's Equity and Incentive Plan, which units are scheduled to vest in three equal annual installments beginning on March 15, 2026, subject to the reporting person's continued employment through each applicable vesting date.

F5: Composed of 25,642 shares held of record by First Interstate Bank TTEE for Dana S Andersson GST Exempt Trust No 1 Dtd 12/11/2020 and 25,642 shares held of record by First Interstate Bank TTEE for James R Scott Jr. GST Exempt Trust No 1 Dtd 12/11/2020.

F6: 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 James R. Scott, Jr. with the indication of direct or indirect ownership in Tables I and II being made from James R. Scott Jr.'s perspective unless expressly noted otherwise by footnote. The nature of beneficial ownership is described in detail by footnote for all reporting persons.