<div id="readability-page-1"><div><p><span>Heyneman Susan Scott Trust Susan Heyneman &amp; First Interstate Wealth Management Co-Ttes Beneficial Owner of First Interstate Bancsystem Inc/MT [FIBK] filed a Form 4 on December 1, 2025 with the Securities and Exchange Commission disclosing the following changes in ownership:</span></p><div><table><tbody><tr><td><span>Date</span></td><td><span>12/1/25</span></td></tr><tr><td><span>Transaction</span></td><td><span>Sale</span></td></tr><tr><td><span>Shares</span></td><td><span>10,000</span></td></tr><tr><td><span>Price</span></td><td><span>$32.75</span></td></tr><tr><td><span>Value</span></td><td><span>$327,500</span></td></tr></tbody></table></div><p><span>Ending Holdings: 224,460 - Indirect</span></p><p><span>For a free trial, or to learn more about our insider trading analysis and data services, please visit http://www.washingtonservice.com or contact us at (301) 913-5100 or send an email to info@washingtonservice.com.</span></p><p><span>Founded in 1970, The Washington Service provides securities professionals with financial, economic and public policy research and data.</span></p><span> </span></div></div>

FIBK

<p>Susan Heyneman, a beneficial owner of First Interstate Bancsystem Inc, sold 10,000 shares at $32.75 each, totaling $327,500, as disclosed in a Form 4 filed with the SEC on December 1, 2025. Her ending holdings are 224,460 shares indirectly.</p>

Owner Heyneman Susan TR Sells 10,000 ($327.5K) Of First Interstate Bancsystem Inc/MT [FIBK]