---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-25-058170"
form_type: "8-K"
ticker: "FIBK"
cik: "0000860413"
company_name: "FIRST INTERSTATE BANCSYSTEM INC"
filed_at: "2025-06-10T23:59:59+00:00"
generated_at: "2026-05-19T16:33:54.857008+00:00"
event_type: "debt"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# First Interstate BancSystem closes $125M offering of 7.625% subordinated notes due 2035

## Summary
- Completed public offering of $125M in 7.625% fixed-to-floating rate subordinated notes due 2035.
- Notes initially treated as Tier 2 capital for regulatory purposes.
- Interest: 7.625% fixed through June 15, 2030, then floating at 3M Term SOFR + 398 bps quarterly.
- Company may redeem notes in whole/part starting June 15, 2030, or upon tax/Tier 2 capital events.
- Notes are unsecured, subordinated, and structurally subordinate to liabilities of bank subsidiary.

## SEC filing metadata
- accession: 0001104659-25-058170
- form_type: 8-K
- ticker: FIBK
- cik: 0000860413
- company_name: FIRST INTERSTATE BANCSYSTEM INC
- filed_at: 2025-06-10T23:59:59+00:00
- event_type: debt
- sentiment: neutral
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 1.01, 2.03, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/860413/000110465925058170/0001104659-25-058170-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/860413/000110465925058170/tm258437d8_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-25-058170
- JSON: https://secwatch.observer/filing/0001104659-25-058170.json
- Plain text: https://secwatch.observer/filing/0001104659-25-058170.txt

## Key facts
- Debt Financings
  FIRST INTERSTATE BANCSYSTEM INC incurred senior notes of $125,000,000 aggregate principal amount with U.S. Bank Trust Company, National Association at 7.625% Fixed-to-Floating Rate maturing 2035.
  - Instrument: senior notes
  - Principal: $125,000,000 aggregate principal amount
  - Counterparty: U.S. Bank Trust Company, National Association
  - Rate: 7.625% Fixed-to-Floating Rate
  - Maturity: 2035
  - Event: incurrence
  source text: On June 10, 2025, First Interstate BancSystem, Inc. (the “Company”) completed its previously announced public offering of $125,000,000 aggregate principal amount of its 7.625% Fixed-to-Floating Rate Subordinated Notes due 2035
  evidence_url: https://www.sec.gov/Archives/edgar/data/860413/000110465925058170/0001104659-25-058170-index.htm

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