FIBK

SEC source: 0000860413-24-000028 · wk-form4_1710887489.xml · nonDerivative · entry 3

Robbins Kristina · CIK 0001930719 · EVP, Chief Operations Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,390

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000028 · wk-form4_1710887489.xml · nonDerivative · entry 2

Robbins Kristina · CIK 0001930719 · EVP, Chief Operations Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,755

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000028 · wk-form4_1710887489.xml · nonDerivative · entry 1

Robbins Kristina · CIK 0001930719 · EVP, Chief Operations Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,933

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000026 · wk-form4_1710881160.xml · nonDerivative · entry 4

Jensen Kirk D · CIK 0001697127 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 27,351

F2 · shares: Shares issuable upon vesting of restricted stock units granted to the reporting person pursuant to the Registrant's 2024 Equity and Incentive Plan. The restricted stock units vest in three equal annual installments beginning on March 15, 2025, subject to the reporting person's continued employment through each applicable vesting date.

SEC source: 0000860413-24-000026 · wk-form4_1710881160.xml · nonDerivative · entry 3

Jensen Kirk D · CIK 0001697127 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,417

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000026 · wk-form4_1710881160.xml · nonDerivative · entry 2

Jensen Kirk D · CIK 0001697127 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,845

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000026 · wk-form4_1710881160.xml · nonDerivative · entry 1

Jensen Kirk D · CIK 0001697127 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,117

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000024 · wk-form4_1710880953.xml · nonDerivative · entry 4

Meyer Lori · CIK 0002003084 · EVP, Chief Information Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 10,330

F2 · shares: Shares issuable upon vesting of restricted stock units granted to the reporting person pursuant to the Registrant's 2024 Equity and Incentive Plan. The restricted stock units vest in three equal annual installments beginning on March 15, 2025, subject to the reporting person's continued employment through each applicable vesting date.

SEC source: 0000860413-24-000024 · wk-form4_1710880953.xml · nonDerivative · entry 3

Meyer Lori · CIK 0002003084 · EVP, Chief Information Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,013

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000024 · wk-form4_1710880953.xml · nonDerivative · entry 2

Meyer Lori · CIK 0002003084 · EVP, Chief Information Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,102

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000024 · wk-form4_1710880953.xml · nonDerivative · entry 1

Meyer Lori · CIK 0002003084 · EVP, Chief Information Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,185

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000022 · wk-form4_1710880522.xml · nonDerivative · entry 4

Asker Lorrie F · CIK 0001965779 · Chief Banking Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,782

F2 · shares: Shares issuable upon vesting of restricted stock units granted to the reporting person pursuant to the Registrant's 2024 Equity and Incentive Plan. The restricted stock units vest in three equal annual installments beginning on March 15, 2025, subject to the reporting person's continued employment through each applicable vesting date.

SEC source: 0000860413-24-000022 · wk-form4_1710880522.xml · nonDerivative · entry 3

Asker Lorrie F · CIK 0001965779 · Chief Banking Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,339

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000022 · wk-form4_1710880522.xml · nonDerivative · entry 2

Asker Lorrie F · CIK 0001965779 · Chief Banking Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,643

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000022 · wk-form4_1710880522.xml · nonDerivative · entry 1

Asker Lorrie F · CIK 0001965779 · Chief Banking Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,795

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000044 · wk-form4a_1711491938.xml · nonDerivative · entry 2

Robbins Kristina · CIK 0001930719 · EVP, Chief Operations Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 13,477

F2 · shares: Shares issuable upon vesting of restricted stock units granted to the reporting person pursuant to the Registrant's 2024 Equity and Incentive Plan. The restricted stock units vest in three equal annual installments beginning on March 15, 2025, subject to the reporting person's continued employment through each applicable vesting date.

SEC source: 0000860413-24-000044 · wk-form4a_1711491938.xml · nonDerivative · entry 1

Robbins Kristina · CIK 0001930719 · EVP, Chief Operations Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,426

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000042 · wk-form4a_1711491727.xml · nonDerivative · entry 3

KNIERIEM KARLYN M · CIK 0001741432 · EVP, Chief Risk Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 25,171

F2 · shares: Shares issuable upon vesting of restricted stock units granted to the reporting person pursuant to the Registrant's 2024 Equity and Incentive Plan. The restricted stock units vest in three equal annual installments beginning on March 15, 2025, subject to the reporting person's continued employment through each applicable vesting date.

SEC source: 0000860413-24-000042 · wk-form4a_1711491727.xml · nonDerivative · entry 2

KNIERIEM KARLYN M · CIK 0001741432 · EVP, Chief Risk Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,079

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000042 · wk-form4a_1711491727.xml · nonDerivative · entry 1

KNIERIEM KARLYN M · CIK 0001741432 · EVP, Chief Risk Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,383

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000040 · wk-form4a_1711491539.xml · nonDerivative · entry 4

Mutch Marcy D · CIK 0001653911 · Exec. Vice Pres. & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 61,747

F2 · shares: Shares issuable upon vesting of restricted stock units granted to the reporting person pursuant to the Registrant's 2024 Equity and Incentive Plan. The restricted stock units vest in three equal annual installments beginning on March 15, 2025, subject to the reporting person's continued employment through each applicable vesting date.

SEC source: 0000860413-24-000040 · wk-form4a_1711491539.xml · nonDerivative · entry 3

Mutch Marcy D · CIK 0001653911 · Exec. Vice Pres. & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 51,388

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000040 · wk-form4a_1711491539.xml · nonDerivative · entry 2

Mutch Marcy D · CIK 0001653911 · Exec. Vice Pres. & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 52,066

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000040 · wk-form4a_1711491539.xml · nonDerivative · entry 1

Mutch Marcy D · CIK 0001653911 · Exec. Vice Pres. & CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 52,518

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000038 · wk-form4a_1711491184.xml · nonDerivative · entry 3

Jensen Kirk D · CIK 0001697127 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 27,453

F2 · shares: Shares issuable upon vesting of restricted stock units granted to the reporting person pursuant to the Registrant's 2024 Equity and Incentive Plan. The restricted stock units vest in three equal annual installments beginning on March 15, 2025, subject to the reporting person's continued employment through each applicable vesting date.

SEC source: 0000860413-24-000038 · wk-form4a_1711491184.xml · nonDerivative · entry 2

Jensen Kirk D · CIK 0001697127 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,519

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000038 · wk-form4a_1711491184.xml · nonDerivative · entry 1

Jensen Kirk D · CIK 0001697127 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,875

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000036 · wk-form4a_1711490891.xml · nonDerivative · entry 4

Asker Lorrie F · CIK 0001965779 · Chief Banking Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,870

F2 · shares: Shares issuable upon vesting of restricted stock units granted to the reporting person pursuant to the Registrant's 2024 Equity and Incentive Plan. The restricted stock units vest in three equal annual installments beginning on March 15, 2025, subject to the reporting person's continued employment through each applicable vesting date.

SEC source: 0000860413-24-000036 · wk-form4a_1711490891.xml · nonDerivative · entry 3

Asker Lorrie F · CIK 0001965779 · Chief Banking Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,427

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000036 · wk-form4a_1711490891.xml · nonDerivative · entry 2

Asker Lorrie F · CIK 0001965779 · Chief Banking Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,685

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000036 · wk-form4a_1711490891.xml · nonDerivative · entry 1

Asker Lorrie F · CIK 0001965779 · Chief Banking Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,814

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-25-000074 · wk-form4_1748625714.xml · nonDerivative · entry 2

Scott James R. Jr · CIK 0001675872 · Director · 10% owner

First Interstate Bank TTEE for Dana S Andersson GST Exempt Trust No 1 Dtd 12/11/2020 · CIK 0001910215 · 10% owner

First Interstate Bank TTEE for James R Scott Jr. GST Exempt Trust No 1 Dtd 12/11/2020 · CIK 0001910352 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 76,178

F2 · shares: 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.

SEC source: 0000860413-24-000020 · wk-form4_1709944011.xml · nonDerivative · entry 1

KNIERIEM KARLYN M · CIK 0001741432 · EVP, Chief Risk Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,599

F1 · price: The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $26.67 to $26.88. 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.

SEC source: 0000860413-24-000018 · wk-form4_1709845463.xml · nonDerivative · entry 1

Asker Lorrie F · CIK 0001965779 · Chief Banking Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,909

F1 · price: The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $26.04 to $26.05. 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.

SEC source: 0000860413-24-000014 · wk-form4_1708469592.xml · nonDerivative · entry 1

KNIERIEM KARLYN M · CIK 0001741432 · EVP, Chief Risk Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 23,499

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000008 · wk-form4_1707769827.xml · nonDerivative · entry 1

Asker Lorrie F · CIK 0001965779 · Chief Banking Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,830

F1 · shares: Disposition to the issuer of issuer securities in payment of minimum required withholding taxes due upon vesting of unvested shares.

SEC source: 0000860413-24-000006 · wk-form4_1707429733.xml · nonDerivative · entry 1

Robbins Kristina · CIK 0001930719 · EVP, Chief Operations Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,047

SEC source: 0001493152-23-045114 · ownership.xml · nonDerivative · entry 1

Homer Scott Jr Trust, Homer Scott Jr. & First Interstate Wealth Management Co Trustees · CIK 0001910945 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 950,753

F1 · balance_after: Composed of 950,753 shares held of record by Homer Scott Jr Trust, First Interstate Wealth Management, Trustee, over which Sandra Scott Suzor has sole voting power and First Interstate Wealth Management has sole dispositive power over the same shares.

F1 · ownership.nature: Composed of 950,753 shares held of record by Homer Scott Jr Trust, First Interstate Wealth Management, Trustee, over which Sandra Scott Suzor has sole voting power and First Interstate Wealth Management has sole dispositive power over the same shares.

F2 · ownership.nature: As a result of certain agreements entered into by and among the reporting person, the Issuer, and certain other stockholders of the Issuer, the reporting person may be deemed a member of a group with the other signatories thereto. The reporting person disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein.

SEC source: 0001493152-24-000011 · ownership.xml · nonDerivative · entry 2

Scott Jeremy · CIK 0001803925 · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · Trust

Disclosed balance after: 69,892

SEC source: 0000860413-23-000198 · wk-form4_1702514106.xml · nonDerivative · entry 5

SCOTT JAMES R · CIK 0001198533 · Director · 10% owner

J.S. Investments Limited Partnership · CIK 0001506291 · 10% owner

James R Scott Trust, James R Scott & First Interstate Wealth Management Co-TTEEs · CIK 0001908712 · 10% owner

Foundation for Community Vitality · CIK 0001908742 · 10% owner

James F Heyneman Conservatorship, James Scott, Conservator · CIK 0001908854 · 10% owner

James F Heyneman Trust, James Scott & First Interstate Wealth Management Co-Trustees · CIK 0001908844 · 10% owner

James R & Christine M Scott Foundation · CIK 0001909853 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · see footnote

Disclosed balance after: 4,388,017

F5 · balance_after: Shares disposed of by James R. Scott's spouse to Foundation for Community Vitality, and shares acquired by Foundation for Community Vitality from James R. Scott's spouse as a bona fide gift.

F3 · ownership.nature: 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 with the indication of direct or indirect ownership in Tables I and II being made from James R. Scott's perspective unless expressly noted otherwise by footnote. The nature of beneficial ownership is described in detail by footnote for all reporting persons.

F6 · ownership.nature: Composed of 1,970,031 shares held of record by James R Scott Trust, James R Scott & First Interstate Wealth Management Co-TTEEs, 15,661 shares held of record by James R Scott's 401k, 35,240 shares held of record by James R and Christine M Scott Foundation, 1,901,036 shares held of record by JS Investments Limited Partnership, 343,599 shares held of record by Foundation for Community Vitality, 73,002 shares held of record by James F Heyneman Conservatorship, James Scott, Conservator, 7,096 shares held of record by James F Heyneman Trust, James Scott & First Interstate Wealth Management Co-Trustees, and 42,352 shares held of record by James R. Scott's spouse.

SEC source: 0000860413-23-000198 · wk-form4_1702514106.xml · nonDerivative · entry 4

SCOTT JAMES R · CIK 0001198533 · Director · 10% owner

J.S. Investments Limited Partnership · CIK 0001506291 · 10% owner

James R Scott Trust, James R Scott & First Interstate Wealth Management Co-TTEEs · CIK 0001908712 · 10% owner

Foundation for Community Vitality · CIK 0001908742 · 10% owner

James F Heyneman Conservatorship, James Scott, Conservator · CIK 0001908854 · 10% owner

James F Heyneman Trust, James Scott & First Interstate Wealth Management Co-Trustees · CIK 0001908844 · 10% owner

James R & Christine M Scott Foundation · CIK 0001909853 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · see footnote

Disclosed balance after: 4,387,092

F5 · balance_after: Shares disposed of by James R. Scott's spouse to Foundation for Community Vitality, and shares acquired by Foundation for Community Vitality from James R. Scott's spouse as a bona fide gift.

F3 · ownership.nature: 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 with the indication of direct or indirect ownership in Tables I and II being made from James R. Scott's perspective unless expressly noted otherwise by footnote. The nature of beneficial ownership is described in detail by footnote for all reporting persons.

F6 · ownership.nature: Composed of 1,970,031 shares held of record by James R Scott Trust, James R Scott & First Interstate Wealth Management Co-TTEEs, 15,661 shares held of record by James R Scott's 401k, 35,240 shares held of record by James R and Christine M Scott Foundation, 1,901,036 shares held of record by JS Investments Limited Partnership, 343,599 shares held of record by Foundation for Community Vitality, 73,002 shares held of record by James F Heyneman Conservatorship, James Scott, Conservator, 7,096 shares held of record by James F Heyneman Trust, James Scott & First Interstate Wealth Management Co-Trustees, and 42,352 shares held of record by James R. Scott's spouse.

SEC source: 0000860413-23-000198 · wk-form4_1702514106.xml · nonDerivative · entry 3

SCOTT JAMES R · CIK 0001198533 · Director · 10% owner

J.S. Investments Limited Partnership · CIK 0001506291 · 10% owner

James R Scott Trust, James R Scott & First Interstate Wealth Management Co-TTEEs · CIK 0001908712 · 10% owner

Foundation for Community Vitality · CIK 0001908742 · 10% owner

James F Heyneman Conservatorship, James Scott, Conservator · CIK 0001908854 · 10% owner

James F Heyneman Trust, James Scott & First Interstate Wealth Management Co-Trustees · CIK 0001908844 · 10% owner

James R & Christine M Scott Foundation · CIK 0001909853 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · see footnote

Disclosed balance after: 4,388,017

F1 · balance_after: Shares disposed of by James R. Scott Trust, James R Scott & First Interstate Wealth Managment Co-TTEEs's to Foundation for Community Vitality, and shares acquired by Foundation for Community Vitality from James R. Scott Trust, James R Scott & First Interstate Wealth Managment Co-TTEEs's, as a bona fide gift.

F3 · ownership.nature: 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 with the indication of direct or indirect ownership in Tables I and II being made from James R. Scott's perspective unless expressly noted otherwise by footnote. The nature of beneficial ownership is described in detail by footnote for all reporting persons.

F4 · ownership.nature: Composed of 1,970,031 shares held of record by James R Scott Trust, James R Scott & First Interstate Wealth Management Co-TTEEs, 15,661 shares held of record by James R Scott's 401k, 35,240 shares held of record by James R and Christine M Scott Foundation, 1,901,036 shares held of record by JS Investments Limited Partnership, 342,674 shares held of record by Foundation for Community Vitality, 73,002 shares held of record by James F Heyneman Conservatorship, James Scott, Conservator, 7,096 shares held of record by James F Heyneman Trust, James Scott & First Interstate Wealth Management Co-Trustees, and 43,277 shares held of record by James R. Scott's spouse.

SEC source: 0000860413-23-000198 · wk-form4_1702514106.xml · nonDerivative · entry 2

SCOTT JAMES R · CIK 0001198533 · Director · 10% owner

J.S. Investments Limited Partnership · CIK 0001506291 · 10% owner

James R Scott Trust, James R Scott & First Interstate Wealth Management Co-TTEEs · CIK 0001908712 · 10% owner

Foundation for Community Vitality · CIK 0001908742 · 10% owner

James F Heyneman Conservatorship, James Scott, Conservator · CIK 0001908854 · 10% owner

James F Heyneman Trust, James Scott & First Interstate Wealth Management Co-Trustees · CIK 0001908844 · 10% owner

James R & Christine M Scott Foundation · CIK 0001909853 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · see footnote

Disclosed balance after: 4,387,092

F1 · balance_after: Shares disposed of by James R. Scott Trust, James R Scott & First Interstate Wealth Managment Co-TTEEs's to Foundation for Community Vitality, and shares acquired by Foundation for Community Vitality from James R. Scott Trust, James R Scott & First Interstate Wealth Managment Co-TTEEs's, as a bona fide gift.

F2 · balance_after: Total Indirect Holdings in James R. Scott's 401(k) dropped by 656 shares due to a distribution mandated by the Internal Revenue Code.

F3 · ownership.nature: 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 with the indication of direct or indirect ownership in Tables I and II being made from James R. Scott's perspective unless expressly noted otherwise by footnote. The nature of beneficial ownership is described in detail by footnote for all reporting persons.

F4 · ownership.nature: Composed of 1,970,031 shares held of record by James R Scott Trust, James R Scott & First Interstate Wealth Management Co-TTEEs, 15,661 shares held of record by James R Scott's 401k, 35,240 shares held of record by James R and Christine M Scott Foundation, 1,901,036 shares held of record by JS Investments Limited Partnership, 342,674 shares held of record by Foundation for Community Vitality, 73,002 shares held of record by James F Heyneman Conservatorship, James Scott, Conservator, 7,096 shares held of record by James F Heyneman Trust, James Scott & First Interstate Wealth Management Co-Trustees, and 43,277 shares held of record by James R. Scott's spouse.

SEC source: 0001493152-23-045376 · ownership.xml · nonDerivative · entry 2

SCOTT JULIE A · CIK 0001234619 · 10% owner

Julie A Scott Rose Trustee of the Julie A Scott Rose Trust Dated 5-14-2002 · CIK 0001908851 · 10% owner

IXL Ltd Liability Co · CIK 0001909090 · 10% owner

Juliana Sarah Scott Rose Trust · CIK 0001909078 · 10% owner

Elizabeth Lauren Scott Rose Trust · CIK 0001908961 · 10% owner

Harper Grace Scott Trust · CIK 0001908895 · 10% owner

Harrison William Scott Trust · CIK 0001908873 · 10% owner

Holland Elizabeth Scott Trust · CIK 0001908953 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 1,149,700

F2 · price: The price reported in column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $28.27 to $28.51. The reporting person undertakes to provide to First Interstate BancSystem, Inc., any security holders 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.

F4 · balance_after: Composed of 520,281 shares held of record by Julie A Scott-Rose Trustee of the Julie A Scott Rose Trust Dated 5-14-02, 209,678 shares held of record by IXL Limited Liability Company, 58,537 shares held of record by Holland Elizabeth Scott Trust, 58,537 shares held of record by Harper GraceScott Trust, 58,538 shares held of record by Harrison William Scott Trust, 122,065 shares held of record by Juliana Sarah Scott Rose Trust, 122,064 shares held of record by Elizabeth Lauren Scott Rose Trust.

F3 · ownership.nature: Composed of 530,281 shares held of record by Julie A Scott-Rose Trustee of the Julie A Scott Rose Trust Dated 5-14-02, 209,678 shares held of record by IXL Limited Liability Company, 58,537 shares held of record by Holland Elizabeth Scott Trust, 58,537 shares held of record by Harper GraceScott Trust, 58,538 shares held of record by Harrison William Scott Trust, 122,065 shares held of record by Juliana Sarah Scott Rose Trust, 122,064 shares held of record by Elizabeth Lauren Scott Rose Trust.

F5 · ownership.nature: 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 Julie Scott Rose with the indication of direct or indirect ownership in Table I and Table II being made from Julie Scott Rose's perspective. The nature of beneficial ownership is described in detail by footnote for all reporting persons.

SEC source: 0001493152-23-045376 · ownership.xml · nonDerivative · entry 1

SCOTT JULIE A · CIK 0001234619 · 10% owner

Julie A Scott Rose Trustee of the Julie A Scott Rose Trust Dated 5-14-2002 · CIK 0001908851 · 10% owner

IXL Ltd Liability Co · CIK 0001909090 · 10% owner

Juliana Sarah Scott Rose Trust · CIK 0001909078 · 10% owner

Elizabeth Lauren Scott Rose Trust · CIK 0001908961 · 10% owner

Harper Grace Scott Trust · CIK 0001908895 · 10% owner

Harrison William Scott Trust · CIK 0001908873 · 10% owner

Holland Elizabeth Scott Trust · CIK 0001908953 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 1,159,700

F1 · price: The price reported in column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $26.03 to $26.29. The reporting person undertakes to provide to First Interstate BancSystem, Inc., any security holders 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.

F3 · balance_after: Composed of 530,281 shares held of record by Julie A Scott-Rose Trustee of the Julie A Scott Rose Trust Dated 5-14-02, 209,678 shares held of record by IXL Limited Liability Company, 58,537 shares held of record by Holland Elizabeth Scott Trust, 58,537 shares held of record by Harper GraceScott Trust, 58,538 shares held of record by Harrison William Scott Trust, 122,065 shares held of record by Juliana Sarah Scott Rose Trust, 122,064 shares held of record by Elizabeth Lauren Scott Rose Trust.

F2 · ownership.nature: The price reported in column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $28.27 to $28.51. The reporting person undertakes to provide to First Interstate BancSystem, Inc., any security holders 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.

F5 · ownership.nature: 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 Julie Scott Rose with the indication of direct or indirect ownership in Table I and Table II being made from Julie Scott Rose's perspective. The nature of beneficial ownership is described in detail by footnote for all reporting persons.

SEC source: 0000860413-24-000012 · wk-form5_1707946650.xml · nonDerivative · entry 3

RILEY KEVIN P · CIK 0001408733 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Indirect · As Custodian under UTMA -1

Disclosed balance after: 1,100

F1 · shares: Shares acquired pursuant to broker-administered dividend reinvestment program.

SEC source: 0001493152-23-038568 · ownership.xml · nonDerivative · entry 1

SCOTT JULIE A · CIK 0001234619 · 10% owner

Julie A Scott Rose Trustee of the Julie A Scott Rose Trust Dated 5-14-2002 · CIK 0001908851 · 10% owner

IXL Ltd Liability Co · CIK 0001909090 · 10% owner

Juliana Sarah Scott Rose Trust · CIK 0001909078 · 10% owner

Elizabeth Lauren Scott Rose Trust · CIK 0001908961 · 10% owner

Harper Grace Scott Trust · CIK 0001908895 · 10% owner

Harrison William Scott Trust · CIK 0001908873 · 10% owner

Holland Elizabeth Scott Trust · CIK 0001908953 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 1,169,700

F1 · price: The price reported in column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $23.24 to $23.44. The reporting person undertakes to provide to First Interstate BancSystem, Inc., any security holders 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 · balance_after: Composed of 540,281 shares held of record by Julie A Scott-Rose Trustee of the Julie A Scott Rose Trust Dated 5-14-02, 209,678 shares held ofrecord by IXL Limited Liability Company, 58,537 shares held of record by Holland Elizabeth Scott Trust, 58,537 shares held of record by Harper GraceScott Trust, 58,538 shares held of record by Harrison William Scott Trust, 122,065 shares held of record by Juliana Sarah Scott Rose Trust, 122,064 shares held of record by Elizabeth Lauren Scott Rose Trust.

F2 · ownership.nature: Composed of 540,281 shares held of record by Julie A Scott-Rose Trustee of the Julie A Scott Rose Trust Dated 5-14-02, 209,678 shares held ofrecord by IXL Limited Liability Company, 58,537 shares held of record by Holland Elizabeth Scott Trust, 58,537 shares held of record by Harper GraceScott Trust, 58,538 shares held of record by Harrison William Scott Trust, 122,065 shares held of record by Juliana Sarah Scott Rose Trust, 122,064 shares held of record by Elizabeth Lauren Scott Rose Trust.

F3 · ownership.nature: 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 Julie Scott Rose with the indication of direct or indirect ownership in Table I and Table II being made from Julie Scott Rose's perspective. The nature of beneficial ownership is described in detail by footnote for all reporting persons.

SEC source: 0000860413-23-000178 · wk-form4_1695055264.xml · nonDerivative · entry 1

RILEY KEVIN P · CIK 0001408733 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 57,956

SEC source: 0001493152-23-032532 · ownership.xml · nonDerivative · entry 5

SCOTT JULIE A · CIK 0001234619 · 10% owner

Julie A Scott Rose Trustee of the Julie A Scott Rose Trust Dated 5-14-2002 · CIK 0001908851 · 10% owner

IXL Ltd Liability Co · CIK 0001909090 · 10% owner

Exempt Thomas W Scott Marital Trust 2 · CIK 0001909336 · 10% owner

Juliana Sarah Scott Rose Trust · CIK 0001909078 · 10% owner

Elizabeth Lauren Scott Rose Trust · CIK 0001908961 · 10% owner

Harper Grace Scott Trust · CIK 0001908895 · 10% owner

Harrison William Scott Trust · CIK 0001908873 · 10% owner

Holland Elizabeth Scott Trust · CIK 0001908953 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 1,183,100

F8 · price: The price reported in column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $25.07 to $25.12. The reporting person undertakes to provide to First Interstate BancSystem, Inc., any security holders 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.

F9 · balance_after: Composed 553681 of shares held of record by Julie A Scott-Rose Trustee of the Julie A Scott Rose Trust Dated 5-14-02, 209,678 shares held of record by IXL Limited Liability Company, 58,537 shares held of record by Holland Elizabeth Scott Trust, 58,537 shares held of record by Harper Grace Scott Trust, 58,538 shares held of record by Harrison William Scott Trust, 122,065 shares held of record by Juliana Sarah Scott Rose Trust, 122,064 shares held of record by Elizabeth Lauren Scott Rose Trust.

F9 · ownership.nature: Composed 553681 of shares held of record by Julie A Scott-Rose Trustee of the Julie A Scott Rose Trust Dated 5-14-02, 209,678 shares held of record by IXL Limited Liability Company, 58,537 shares held of record by Holland Elizabeth Scott Trust, 58,537 shares held of record by Harper Grace Scott Trust, 58,538 shares held of record by Harrison William Scott Trust, 122,065 shares held of record by Juliana Sarah Scott Rose Trust, 122,064 shares held of record by Elizabeth Lauren Scott Rose Trust.

F10 · ownership.nature: 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 Julie Scott Rose with the indication of direct or indirect ownership in Table I and Table II being made from Julie Scott Rose's perspective. The nature of beneficial ownership is described in detail by footnote for all reporting persons.

SEC source: 0000860413-23-000176 · wk-form4_1694731668.xml · nonDerivative · entry 4

Scott Jonathan R · CIK 0001361935 · Director · 10% owner

IXL Ltd Liability Co · CIK 0001909090 · 10% owner

Jonathan Scott as Trustee of the Jonathan R Scott Trust Dated as of 4/21/04 · CIK 0001908962 · 10% owner

Harrison William Scott Trust · CIK 0001908873 · 10% owner

Holland Elizabeth Scott Trust · CIK 0001908953 · 10% owner

Harper Grace Scott Trust · CIK 0001908895 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 1,051,162

F5 · price: The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.78 to $25.01. 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 · ownership.nature: 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.

F6 · ownership.nature: Composed of 615,872 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, 58,537 shares held of record by Holland Elizabeth Scott Trust, 58,537 shares held of record by Harper Grace Scott Trust, 58,538 shares held of record by Harrison William Scott Trust and 50,000 shares held of record by Jonathan Scott's spouse.