{"schema_version":"secwatch.filing_event.v1","accession":"0000860413-26-000088","form_type":"8-K","ticker":"FIBK","cik":"0000860413","company_name":"FIRST INTERSTATE BANCSYSTEM INC","filed_at":"2026-08-21T13:20:20+00:00","discovered_at":"2026-08-21T13:21:19.412587+00:00","generated_at":"2026-08-21T13:21:26.565086+00:00","sec_items":["5.02","9.01"],"event_type":"leadership","sentiment":"neutral","materiality_score":0.35,"calibrated_materiality_score":0.35,"confidence":"high","headline":"First Interstate Bancsystem appoints Jeff Lee as EVP and COO effective Sept 14, 2026","bullets":["Jeff Lee, 57, named EVP and Chief Operations Officer of FIBK and First Interstate Bank, starting Sept 14, 2026.","Initial annual base salary set at $480,000; RSU grant of $200,000 vesting in three equal annual installments from Sept 2027.","Lee brings 20+ years banking ops/tech experience; previously COO/CTO at Seacoast Banking Corp (SBCF) from 2021-2024.","Employment agreement initial one-year term with automatic renewal unless terminated 90 days prior."],"urls":{"canonical":"https://secwatch.observer/filing/0000860413-26-000088","json":"https://secwatch.observer/filing/0000860413-26-000088.json","markdown":"https://secwatch.observer/filing/0000860413-26-000088.md","text":"https://secwatch.observer/filing/0000860413-26-000088.txt","edgar_index":"https://www.sec.gov/Archives/edgar/data/860413/000086041326000088/0000860413-26-000088-index.htm","edgar_primary_document":"https://www.sec.gov/Archives/edgar/data/860413/000086041326000088/fibk-20260821.htm"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-08-21T13:21:26.565086+00:00"},"review":{"review_status":"machine_generated","human_reviewed":false,"corrected":false,"correction_note":null,"correction_timestamp":null,"superseded_by":null,"related_filings":[]},"source_grounded_claims":[{"claim_id":"e8507f45c2","claim":"Jeff Lee was appointed as Executive Vice President and Chief Operations Officer at FIRST INTERSTATE BANCSYSTEM INC.","evidence_excerpt":"On August 21, 2026, the registrant announced the appointment of Mr. Jeff Lee to become Executive Vice President and Chief Operations Officer of the registrant and its wholly owned subsidiary, First Interstate Bank (the “Bank”), with Mr. Lee’s employment starting date expected to begin formally on September 14, 2026 (the “Effective Date”).","evidence_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/860413/000086041326000088/0000860413-26-000088-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"appointed"},{"label":"Role","value":"Executive Vice President and Chief Operations Officer"}],"fact_type":"executive_change"}],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}