<SEC-DOCUMENT>0001950047-23-003994.txt : 20230913
<SEC-HEADER>0001950047-23-003994.hdr.sgml : 20230913
<ACCEPTANCE-DATETIME>20230913161858
ACCESSION NUMBER:		0001950047-23-003994
CONFORMED SUBMISSION TYPE:	144
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20230913
DATE AS OF CHANGE:		20230913

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FIRST INTERSTATE BANCSYSTEM INC
		CENTRAL INDEX KEY:			0000860413
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				810331430
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		144
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	001-34653
		FILM NUMBER:		231252925

	BUSINESS ADDRESS:	
		STREET 1:		401 NO 31ST STREET
		CITY:			BILLINGS
		STATE:			MT
		ZIP:			59101
		BUSINESS PHONE:		4062555311

	MAIL ADDRESS:	
		STREET 1:		401 NO 31ST STREET
		CITY:			BILLINGS
		STATE:			MT
		ZIP:			59101

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FIRST INTERSTATE BANCSYSTEM OF MONTANA INC
		DATE OF NAME CHANGE:	19930615

REPORTING-OWNER:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Julie A Scott Rose Trustee of the Julie A Scott Rose Trust Dated 5-14-2002
		CENTRAL INDEX KEY:			0001908851
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			WY
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		144

	BUSINESS ADDRESS:	
		STREET 1:		31 BUSBEE ROAD
		CITY:			ASHEVILLE
		STATE:			NC
		ZIP:			28803
		BUSINESS PHONE:		307-752-5605

	MAIL ADDRESS:	
		STREET 1:		31 BUSBEE ROAD
		CITY:			ASHEVILLE
		STATE:			NC
		ZIP:			28803
</SEC-HEADER>
<DOCUMENT>
<TYPE>144
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:ns2="http://www.sec.gov/edgar/common">
    <headerData>
        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001908851</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0000860413</issuerCik>
            <issuerName>FIRST INTERSTATE BANCSYSTEM INC.</issuerName>
            <secFileNumber>001-34653</secFileNumber>
            <issuerAddress>
                <ns2:street1>401 North 31st Street</ns2:street1>
                <ns2:city>Billings</ns2:city>
                <ns2:stateOrCountry>MT</ns2:stateOrCountry>
                <ns2:zipCode>59101</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>(406) 255-5311</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>JULIE SCOTT ROSE TRUST</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Family Ownership</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>38th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>20000</noOfUnitsSold>
            <aggregateMarketValue>501807.25</aggregateMarketValue>
            <noOfUnitsOutstanding>105018309</noOfUnitsOutstanding>
            <approxSaleDate>09/13/2023</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>09/11/2023</acquiredDate>
            <natureOfAcquisitionTransaction>Distribution from a Trust or an Estate</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Tom and Joan Scott</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>20000</amountOfSecuritiesAcquired>
            <paymentDate>09/11/2023</paymentDate>
            <natureOfPayment>Estate Settlement</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>Julie Scott Rose Trust</name>
                <address>
                    <ns2:street1>401 North 31st Street</ns2:street1>
                    <ns2:city>Billings</ns2:city>
                    <ns2:stateOrCountry>MT</ns2:stateOrCountry>
                    <ns2:zipCode>59101</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>09/12/2023</saleDate>
            <amountOfSecuritiesSold>11928</amountOfSecuritiesSold>
            <grossProceeds>298654.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>Julie Scott Rose Trust</name>
                <address>
                    <ns2:street1>401 North 31st Street</ns2:street1>
                    <ns2:city>Billings</ns2:city>
                    <ns2:stateOrCountry>MT</ns2:stateOrCountry>
                    <ns2:zipCode>59101</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>09/11/2023</saleDate>
            <amountOfSecuritiesSold>8072</amountOfSecuritiesSold>
            <grossProceeds>201450.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>09/13/2023</noticeDate>
            <planAdoptionDates/>
            <signature>/s/ Julie Scott Rose, Trustee</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
