---
schema_version: "secwatch.filing_event.v1"
accession: "0000860413-25-000036"
form_type: "8-K"
ticker: "FIBK"
cik: "0000860413"
company_name: "FIRST INTERSTATE BANCSYSTEM INC"
filed_at: "2025-03-19T23:59:59+00:00"
generated_at: "2026-05-24T12:40:27.408169+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.4
calibrated_materiality_score: 0.4
confidence: "high"
source: SEC EDGAR
---

# First Interstate BancSystem announces two director retirements effective at 2025 annual meeting

## Summary
- Thomas E. Henning resigned per retirement age policy (age 72) as Class II director effective at 2025 annual meeting.
- Frances P. Grieb voluntarily retired from board effective at 2025 annual meeting; will not stand for re-election.
- Both directors joined board via Great Western Bancorp acquisition in 2022; will continue in current roles until effective date.
- Neither resignation relates to any disagreement with the company's operations, policies, or practices.

## SEC filing metadata
- accession: 0000860413-25-000036
- form_type: 8-K
- ticker: FIBK
- cik: 0000860413
- company_name: FIRST INTERSTATE BANCSYSTEM INC
- filed_at: 2025-03-19T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.4
- calibrated_materiality_score: 0.4
- confidence: high
- sec_items: 5.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/860413/000086041325000036/0000860413-25-000036-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/860413/000086041325000036/fibk-20250314.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000860413-25-000036
- JSON: https://secwatch.observer/filing/0000860413-25-000036.json
- Plain text: https://secwatch.observer/filing/0000860413-25-000036.txt

## Key facts
- Executive change
  Frances P. Grieb retired as Director at FIRST INTERSTATE BANCSYSTEM INC.
  - Action: retired
  - Role: Director
  source text: Ms. Frances P. Grieb, an incumbent Class I director, informed the Board of her decision to retire from the Board effective at the 2025 annual meeting of stockholders and as a result to not seek to stand for re-election at the 2025 meeting.
  evidence_url: https://www.sec.gov/Archives/edgar/data/860413/000086041325000036/0000860413-25-000036-index.htm
- Executive change
  Thomas E. Henning resigned as Director at FIRST INTERSTATE BANCSYSTEM INC.
  - Action: resigned
  - Role: Director
  source text: Mr. Thomas E. Henning, having reached the retirement age of 72 on March 14, 2025, resigned from the registrant’s Board of Directors (the “Board”), with such resignation to become effective as of the registrant’s 2025 annual meeting of stockholders as provided in the guidelines.
  evidence_url: https://www.sec.gov/Archives/edgar/data/860413/000086041325000036/0000860413-25-000036-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.