Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Scott Jonathan R 2. Issuer Name and Ticker or Trading Symbol FIRST INTERSTATE BANCSYSTEM INC [FIBK] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) PO BOX 7113 3. Date of Earliest Transaction (Month/Day/Year) 10/07/2025 (Street) BILLINGS, MT 59103 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 10/07/2025 S 13,715 D $32.09(1) 959,109 I See Footnote(2)(3) Common Stock 10/08/2025 S 5,600 D $32.01(4) 953,509 I See Footnote(3)(5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Scott Jonathan R PO BOX 7113 BILLINGS, MT 59103		X
Jonathan Scott as Trustee of the Jonathan R Scott Trust Dated as of 4/21/04 PO BOX 7113 BILLINGS, MT 59103		X
Harrison William Scott Trust PO BOX 7113 BILLINGS, MT 59103		X
Harper Grace Scott Trust PO BOX 7113 BILLINGS, MT 59103		X
Holland Elizabeth Scott Trust PO BOX 7113 BILLINGS, MT 59103		X
IXL Ltd Liability Co PO BOX 7113 BILLINGS, MT 59103		X

Signatures

/s/ Kirk D. Jensen, as attorney in fact for reporting person		10/08/2025
**Signature of Reporting Person		Date
JONATHAN SCOTT AS TRUSTEE OF THE JONATHAN R SCOTT TRUST DATED AS OF 4/21/04, By: +		10/08/2025
**Signature of Reporting Person		Date
IXL Limited Liability Company, By:+		10/08/2025
**Signature of Reporting Person		Date
HOLLAND ELIZABETH SCOTT TRUST, By: +		10/08/2025
**Signature of Reporting Person		Date
HARPER GRACE SCOTT TRUST, By: +		10/08/2025
**Signature of Reporting Person		Date
HARRISON WILLIAM SCOTT TRUST, By: +		10/08/2025
**Signature of Reporting Person		Date
+/s/ Timothy Leuthold, Attorney-in-Fact for Reporting Person		10/08/2025
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $32.00 to $32.33. 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.
(2)	Composed of 589,771 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.
(3)	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.
(4)	The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $32.00 to $32.07. 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.
(5)	Composed of 584,171 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.

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