BlackRock (NYSE: BLK) discloses 12.9% holding in First Interstate

Rhea-AI Filing Summary

BlackRock, Inc. filed an amended Schedule 13G reporting passive ownership of Class A stock of First Interstate BancSystem Inc. as of 12/31/2025. BlackRock reports beneficial ownership of 13,290,004 Class A shares, representing 12.9% of the class. It has sole voting power over 13,073,231 shares and sole dispositive power over 13,290,004 shares, with no shared voting or dispositive power.

The filing explains that these holdings are attributed to certain BlackRock business units, and that one holder, iShares Core S&P Small-Cap ETF, has an interest in more than five percent of the issuer’s common stock. BlackRock certifies the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of the company.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 10)

FIRST INTERSTATE BANCSYSTEM INC

(Name of Issuer)

Class A Stock

(Title of Class of Securities)

32055Y201

(CUSIP Number)

12/31/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 32055Y201

1

Names of Reporting Persons

BlackRock, Inc.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 13,073,231.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 13,290,004.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

13,290,004.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

12.9 %

12

Type of Reporting Person (See Instructions)

HC

SCHEDULE 13G

Item 1.
(a)	Name of issuer: FIRST INTERSTATE BANCSYSTEM INC
(b)	Address of issuer's principal executive offices: 401 NORTH 31ST STREET BILLINGS MT 59101
Item 2.
(a)	Name of person filing: BlackRock, Inc. In accordance with SEC Release No. 34-39538 (January 12, 1998), this Schedule 13G reflects the securities beneficially owned, or deemed to be beneficially owned, by certain business units (collectively, the "Reporting Business Units") of BlackRock, Inc. and its subsidiaries and affiliates. It does not include securities, if any, beneficially owned by other business units whose beneficial ownership of securities are disaggregated from that of the Reporting Business Units in accordance with such release.
(b)	Address or principal business office or, if none, residence: BlackRock, Inc., 50 Hudson Yards New York, NY 10001
(c)	Citizenship: See Item 4 of Cover Page
(d)	Title of class of securities: Class A Stock
(e)	CUSIP No.: 32055Y201
Item 4.	Ownership
(a)	Amount beneficially owned: 13290004
(b)	Percent of class: 12.9 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 13073231
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 13290004
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. The interest of 1 such person, iShares Core S&P Small-Cap ETF, in the common stock of FIRST INTERSTATE BANCSYSTEM INC is more than five percent of the total outstanding common stock.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. See Exhibit 99
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

BlackRock, Inc.

Signature:	Spencer Fleming
Name/Title:	Managing Director
Date:	01/08/2026

Exhibit Information

Exhibit 24: Power of Attorney Exhibit 99: Item 7

FAQ

What percentage of First Interstate BancSystem does BlackRock (BLK) report owning?

BlackRock, Inc. reports beneficial ownership of 12.9% of the Class A stock of First Interstate BancSystem Inc. as stated in the Schedule 13G/A.

How many First Interstate BancSystem shares does BlackRock report on its Schedule 13G/A?

BlackRock reports beneficial ownership of 13,290,004 Class A shares of First Interstate BancSystem Inc. in the amended Schedule 13G.

What level of voting and dispositive power does BlackRock have over these First Interstate BancSystem shares?

BlackRock has sole voting power over 13,073,231 shares and sole dispositive power over 13,290,004 shares, with no shared voting or dispositive power reported.

Is BlackRock’s stake in First Interstate BancSystem reported as passive or for control purposes?

BlackRock certifies that the securities were acquired and are held in the ordinary course of business and were not acquired or held for the purpose of changing or influencing control of First Interstate BancSystem.

Which other entity related to BlackRock holds more than 5% of First Interstate BancSystem’s common stock?

The filing notes that iShares Core S&P Small-Cap ETF has an interest in more than five percent of the common stock of First Interstate BancSystem Inc.

Who signed the amended Schedule 13G for BlackRock regarding First Interstate BancSystem?

The statement was signed by Spencer Fleming, identified as a Managing Director of BlackRock, Inc., on 01/08/2026.