FIRST INTERSTATE BANCSYSTEM INC

(1) BASIS OF PRESENTATION

The accompanying unaudited consolidated financial statements of First Interstate BancSystem, Inc., and its consolidated subsidiaries, including its wholly-owned subsidiary, First Interstate Bank (“FIB”) (collectively, the “Company”) contain all adjustments (all of which are of a normal recurring nature) necessary to present fairly the financial position of the Company at September 30, 2025 and December 31, 2024, the results of operations, changes in stockholders’ equity, and cash flows for each of the three and the nine months ended September 30, 2025 and 2024, in conformity with U.S. generally accepted accounting principles (“GAAP”). The balance sheet information at December 31, 2024 is derived from audited consolidated financial statements. The unaudited consolidated financial statements have been prepared in conformity with the required interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X; and therefore, do not include all of the information and footnotes required by GAAP for a complete set of financial statements. Certain reclassifications, none of which were material, have been made to conform the Company’s prior year financial statements to the financial statements as of September 30, 2025. These reclassifications did not change previously reported net income, financial condition, cash flows, or stockholders’ equity.

The Company has identified one reporting unit and one operating segment, community banking, which encompasses commercial and consumer banking services to serve a similar base of clients utilizing company-wide offerings of similar products and services managed through similar processes and platforms offered to individuals, businesses, municipalities, and other entities, whose primary sources of revenue are interest income on loans, investment securities and other interest-earning assets and fee income earned on its products and services. Its expenses consist of interest expense on deposits and borrowed funds, provision for credit losses, other operating expenses and income taxes, as further described below. The Company manages its business activities on a consolidated basis.

The Company’s chief operating decision maker (“CODM”) is its Chief Executive Officer who is charged with management of the Company and is responsible for the evaluation of operating performance and decision making about the allocation of capital and resources.

The CODM regularly assesses performance of the single operating and reporting segment and decides how to allocate resources based on net income calculated on the same basis as is net income reported in the Company’s consolidated statements of income. The CODM is also regularly provided with expense information at a level consistent with that disclosed in the Company’s consolidated statements of income.

The Company’s principal expenses include: (i) interest expense on deposit accounts and other borrowings; (ii) salaries and employee benefits; (iii) information technology and communication costs primarily associated with maintaining loan and deposit functions; (iv) furniture, equipment, and occupancy expenses for maintaining our facilities; (v) professional fees, including FDIC insurance assessments; (vi) income tax expense; (vii) provisions for credit losses; (viii) intangible amortization; (ix) other real estate owned expenses; and (x) other segment expenses including legal expenses, advertising and promotion, donations, credit card rewards expense, fees associated with originating and closing loans, insurance, and other expenses necessary to support our employees and service our clients. See the consolidated financial statements for other financial information regarding the Company’s operating segment.

The accounting policies of the segment are the same as those described in "Note 1 - Summary of Significant Accounting Policies" of the Company's Annual Report on Form 10-K for the year ended December 31, 2024.

These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024, which includes a description of significant accounting policies. Operating results for the three and the nine months ended September 30, 2025 are not necessarily indicative of the results that may be expected for the year ending December 31, 2025.

(2) INVESTMENT SECURITIES

The amortized cost and the approximate fair values of investment securities are summarized as follows:

The following tables show the gross unrealized losses and fair values of available-for-sale investment securities and the length of time individual investment securities have been in an unrealized loss position as of September 30, 2025 and December 31, 2024.

The Company determines the allowance for credit losses on both available-for-sale and held-to-maturity investment securities by a discounted cash flow approach when needed, using each security’s effective interest rate at the time of purchase or upon acquisition. The allowance for credit losses for available-for-sale investment securities is measured as the amount by which an investment security’s amortized cost exceeds the net present value of expected future cash flows, however, the amount of credit losses is limited to the amount of a security’s unrealized loss. The allowance for credit loss on held-to-maturity investment securities is representative of current expected credit losses that management expects to be incurred over the life of the investment and established through a charge to provision for credit losses in current period earnings. For held-to-maturity investment securities, the Company has the intent and ability to hold these investment securities to maturity.

The investment securities portfolio primarily contains securities that are guaranteed by a sovereign entity or are generally considered to have non-credit related risks, such as interest rate risk or liquidity factors. The Company considers whether the securities are issued by the federal government or its agencies and whether downgrades by bond rating agencies have occurred.

As of September 30, 2025 and December 31, 2024, the Company had 633 and 670 individual available-for-sale investment securities, respectively, that were in an unrealized loss position, which was related primarily to fluctuations in current interest rates. As of September 30, 2025, the Company does not intend to sell nor is it more likely than not the Company will be required to sell any available-for-sale securities with unrealized losses.

The Company hadno allowance for credit losses on available-for-sale investment securities as of September 30, 2025 and December 31, 2024.

On a quarterly basis, the Company refreshes the credit quality indicator of each held-to-maturity security. As of September 30, 2025 and December 31, 2024, the held-to-maturity portfolio is primarily composed of investment grade or better securities. The Company had a $0.7 million and a $0.9 million allowance for credit losses for held-to-maturity corporate and state, county, and municipal investment securities as of September 30, 2025 and December 31, 2024, respectively.

As of September 30, 2025 and December 31, 2024, the Company had $23.2 million and $29.6 million, respectively, of accrued interest receivable from investment securities on the consolidated balance sheets. Accrued interest receivable is presented as a separate line item on the consolidated balance sheets and is not included in the carrying value of our securities.

During the three months ended September 30, 2025 and 2024, there were no gross realized gains or losses on the disposition of available-for-sale investment securities.

The following schedule represents the amortized cost of debt securities by contractual maturity except for maturities of mortgage-backed securities, which have been adjusted to reflect shorter maturities based upon estimated prepayments of principal.

As of September 30, 2025, the Company held investment securities callable within one year having amortized costs and estimated fair values of $682.2 million and $654.1 million, respectively. These investment securities are primarily included in the “after five year” categories in the table above.

As of September 30, 2025 and December 31, 2024, the Company had securities with carrying values of $2,877.5 million and $3,460.2 million, respectively, for investment securities pledged to secure public deposits, derivatives, and securities sold under repurchase agreements that had estimated fair values as of September 30, 2025 and December 31, 2024, of $2,664.0 million and $3,092.6 million, respectively. All securities sold under repurchase agreements are with clients and mature on the next banking day. The Company retains possession of the underlying securities sold under repurchase agreements.

As of September 30, 2025 and December 31, 2024, the Company held $106.8 million and $177.4 million, respectively, in equity securities primarily in a combination of Federal Reserve Bank and Federal Home Loan Bank (“FHLB”) stocks, which are restricted nonmarketable securities acquired to meet regulatory requirements and related to outstanding borrowings. These securities are carried at cost.

(3) LOANS HELD FOR SALE

Residential mortgage loans that the Company originated with the intent to sell are recorded at fair value. The following table presents (i) residential mortgage loans recorded at fair value and (ii) other loans held for sale at lower of cost or market by class of receivable related to the sale of the Arizona and Kansas branches (which was pending as of September 30, 2025), net of a $6.1 million valuation allowance, in addition to the pending sale of approximately $645.0 million in deposits, for the dates indicated:

(4) LOANS HELD FOR INVESTMENT

The following table presents loans by class of receivable and portfolio segment as of the dates indicated:

Allowance for Credit Losses

The following tables represent, by loan portfolio segments, the activity in the allowance for credit losses for loans held for investment:

Collateral-Dependent Loans

A collateral-dependent loan relies substantially on the operation or sale of the collateral securing the loan for repayment. A loan may become collateral-dependent when foreclosure is probable or the borrower is experiencing financial difficulty and its sources of repayment become inadequate over time.

The following tables present the principal balance of collateral-dependent loans by class of receivable as of the dates indicated:

Loans are considered past due if the required principal and interest payments have not been received 30 days or more past the contractual payment due date. Loans classified in the following table as 90 days or more past due continue to accrue interest. The following tables present the contractual aging of the Company’s recorded principal balance of loans by class of receivable as of the dates indicated:

(1) As of September 30, 2025 and December 31, 2024, none of our non-accrual loans were earning interest income. Additionally, $2.0 million and $3.5 million interest income was recognized on non-accrual loans during the three and the nine months ended September 30, 2025, respectively, and $1.0 million and $1.8 million interest income was recognized on non-accrual loans during the three and the nine months ended September 30, 2024, respectively. There were $0.4 million and $2.9 million in reversals of accrued interest during the three and the nine months ended September 30, 2025, respectively, and $0.4 million and $2.4 million in reversals of accrued interest during the three and the nine months ended September 30, 2024, respectively.

(2) As of September 30, 2025 and December 31, 2024, there were approximately $101.0 million and $56.9 million, respectively, of non-accrual loans for which there was no related allowance for credit loss, as these loans had sufficient collateral securing the loan for repayment.

(3) As of September 30, 2025, there were approximately $13.0 million, $5.5 million, and $88.6 million of non-accrual loans that were 30-59 days past due, 60-89 days past due, and 90 days or more past due, respectively. As of December 31, 2024, there were approximately $13.5 million, $6.2 million, and $40.5 million of non-accrual loans that were 30-59 days past due, 60-89 days past due, and 90 days or more past due, respectively.

Modifications to Borrowers Experiencing Financial Difficulty

Modifications of loans are made in the ordinary course of business and are completed on a case-by-case basis through negotiation with the borrower in connection with the ongoing loan collection processes. Loan modifications are made to provide payment relief to borrowers experiencing financial difficulty.

From time to time, we may modify certain loans to borrowers who are experiencing financial difficulty. In some cases, these modifications may result in new loans. Loan modifications to borrowers experiencing financial difficulty may be in the form of principal forgiveness, an interest rate reduction, an other-than-insignificant payment delay, a term extension, or a combination thereof, among other things.

The following tables present the amortized cost basis of loans, by class and by type of modification, at September 30, 2025 and 2024 that were both experiencing financial difficulty and modified during the periods indicated. The percentage of the principal balance of loans that were modified to borrowers in financial distress as compared to the principal balance of each class of receivable is also presented below:

(1) Based on the principal balance as of period end, divided by the period end principal balance of the corresponding class of receivables.

(2) As of September 30, 2025 and 2024, the Company excluded $0.7 million and $1.1 million, respectively, in accrued interest from the amortized cost of the identified loans.

The following tables present the financial effect of the loan modifications presented above to borrowers experiencing financial difficulty during the periods indicated:

(1) Balances based on loan original contractual terms.

The Company monitors the performance of loan modifications to borrowers experiencing financial difficulty to understand the effectiveness of its modification efforts. Of the accruing loans that were modified during the twelve-months ended September 30, 2025 and 2024, there were $0.8 million and $0.5 million of loans classified as past due 30 days or more, respectively, with the remaining accruing loans performing in accordance with the modified terms and classified as current at September 30, 2025 and 2024. Of the non-accrual loans that were modified during the twelve-months ended September 30, 2025 and 2024, there were $10.5 million and $9.2 million of loans classified as past due 30 days or more, respectively, with the remaining non-accrual loans performing in accordance with the modified terms and classified as current at September 30, 2025 and 2024.

There were no commitments to lend additional funds related to the loan modifications to borrowers experiencing financial difficulty during the three months ended September 30, 2025 and 2024.

There were $2.1 million and $1.3 million of payment defaults on these loans subsequent to their modifications during the twelve-months ended September 30, 2025 and 2024. The Company considers a payment default to occur when the loan is 90 days or more past due or the loan is placed on non-accrual status after the modification. The Company monitors the performance of modified loans on an ongoing basis. In the event of subsequent default, the allowance for credit losses continues to be reassessed based on an individual evaluation of each loan. The modifications made during the periods presented did not significantly impact the Company’s determination of the allowance for credit losses.

Credit Quality Indicators

As part of the on-going and continuous monitoring of the credit quality of the Company’s loan portfolio, management tracks internally assigned risk classifications of loans based on relevant information about the ability of borrowers to service their debt. The factors considered by the Company include, among other factors, the borrower’s current financial information, historical payment experience, credit documentation, public information, and current economic trends. The Company analyzes loans individually to classify the credit risk of the loans. This analysis generally includes loans with an outstanding balance greater than $1.0 million, which are generally considered non-homogeneous loans, such as commercial loans and commercial real estate loans. This analysis is performed no less than on an annual basis, depending upon the size of exposure and the contractual obligations governing the borrower’s financial reporting frequency. Homogeneous loans, including small business loans, are typically monitored by payment performance. The Company internally risk rates its loans in accordance with a Uniform Classification System developed jointly by the various bank regulatory agencies. The Uniform Classification System defines three broad categories of criticized assets, which the Company uses as credit quality indicators in addition to the 6 Pass ratings in its 10-point rating scale:

Special Mention — includes loans that exhibit a potential weakness in financial condition, loan structure, or documentation that warrants management’s close attention. If not promptly corrected, the potential weaknesses may result in deterioration of the repayment prospects for the loan or of the institution’s credit position at some future date.

Substandard — includes loans that are inadequately protected by the current net worth and paying capacity of the borrower which have well-defined weaknesses that jeopardize the liquidation of the debt. Although the primary source of repayment for a substandard loan may not currently be sufficient, collateral or other sources of repayment are sufficient to satisfy the debt.

Doubtful — includes loans that exhibit pronounced weaknesses based on currently existing facts, conditions, and values to a point where collection or liquidation for full repayment is highly questionable and improbable. Doubtful loans are required to be placed on non-accrual status and are assigned specific loss exposure.

Loans not meeting the criteria above that are analyzed individually as part of the above-described process are considered pass-rated loans. A pass-rated loan can be assets where there is virtually no credit risk, such as cash secured loans with funds on deposit with the Bank. Pass-rated loans also include loans that are on our watch lists; these loans are currently performing but are subject to closer monitoring due to certain risk factors or emerging weaknesses that could, if not corrected, result in future deterioration of repayment capacity. These loans do not meet the criteria for classification as Special Mention or a criticized asset, but are included on the bank’s internal watch list to ensure proactive management and early identification of potential credit issues.

The Company evaluates the credit quality and loan performance for the allowance for credit losses of the following class of receivables by origination year using the origination date or the loan’s subsequent renewal or modification date based on the aforementioned risk scale as of and for the periods ended:

The Company evaluates the credit quality, loan performance, and the allowance for credit losses of its residential and consumer loan portfolios based primarily on the aging status of the loan and borrower payment activity. Accordingly, loans on non-accrual status and loans past due 90 days or more and still accruing interest are considered nonperforming for purposes of credit quality evaluation. The following tables present the recorded investment of these loan portfolios based on the credit risk profile of loans that are performing and loans that are nonperforming as of the periods indicated:

The following table summarizes the current-period gross charge-offs by class of receivable and portfolio segment as of the dates indicated:

In the normal course of business, there wereno material purchases of portfolio loans andno material sales of loans held for investment during the three and the nine months ended September 30, 2025 or 2024.

(5) DERIVATIVES AND HEDGING ACTIVITIES

The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through the management of its business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of its assets and liabilities and derivative financial instruments. The Company enters into derivative financial instruments, such as interest rate swap contracts to manage or hedge exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates and interest rate exposures. The Company does not enter into interest rate swap agreements for trading or speculative purposes.

The Company sells residential mortgage loans on either a best efforts or mandatory delivery basis. The Company mitigates the effect of the interest rate risk inherent in providing interest rate lock commitments by entering into forward loan sales contracts. The forward loan sales contracts are recorded at fair value with changes in fair value recorded through earnings and are not designated as accounting hedges. Exclusive of the fair value component associated with the projected cash flows from the loan delivery to the investor, the changes in fair value related to movements in market rates of the interest rate lock commitments and the forward loan sales contracts generally move in opposite directions, and the net impact of changes in these valuations on net income during the loan commitment period is generally inconsequential. When the loan is funded to the borrower, the interest rate lock commitment expires, and the Company records a loan held for sale. The forward loan sales contract acts as a hedge against movements in the market interest rates from the time the Company enters into the interest rate lock commitment. The changes in measurement of the estimated fair values of the interest rate lock commitments and forward loan sales contracts are included in mortgage banking revenues in the accompanying consolidated statements of income. The Company charges a fee for these transactions, which is included in mortgage banking revenues on the consolidated statements of income which werenot material for the periods ended September 30, 2025 and 2024.

The Company also enters into derivative contracts related to transactions in which the Company enters into an interest rate swap with a client while at the same time entering into an offsetting interest rate swap with a third-party financial institution. Because the Company acts as an intermediary for the client, changes in the fair value of the underlying derivative contracts primarily offset each other and do not significantly impact the Company’s results of operations. The Company charges a fee for these transactions, which is included in other service charges, commissions, and fees on the consolidated statements of income which werenot material for the periods ended September 30, 2025 and 2024.

Cash Flow Hedges of Interest Rate Risk

The Company’s objectives in using interest rate derivatives are to add stability to interest income (expense) and to manage its exposure to interest rate movements. To accomplish these objectives, the Company primarily uses interest rate swaps and collars as part of its interest rate risk management strategy.

As of September 30, 2025, the Company does not have any active interest rate derivatives designated as cash flow hedges. Amounts previously deferred in AOCI will be reclassified to income over time as the previously hedged, forecasted transactions remain probable of occurring. The Company continues to monitor its interest rate risk exposure and may enter into new derivative contracts in the future as part of its ongoing risk management activities.

Fair Value Hedges of Interest Rate Risk

The Company is exposed to changes in the fair value of fixed-rate assets due to changes in benchmark interest rates. The Company uses interest rate swaps to manage its exposure to changes in fair value on these instruments attributable to changes in the designated benchmark interest rate. Interest rate swaps designated as fair value hedges involve the payment of fixed-rate amounts to a counterparty in exchange for the Company receiving variable-rate payments over the life of the agreements.

For derivatives designated and that qualify as fair value hedges, the gain or loss on the derivative as well as the offsetting loss or gain on the hedged item attributable to the hedged risk are recognized in interest income. As of September 30, 2025, the Company does not have any active derivatives designated as fair value hedges.

Derivatives Not Designated as Accounting Hedges

Derivative instruments not designated as accounting hedges are not speculative and result from a service the Company provides to certain customers. The Company executes interest rate swaps with commercial banking customers to facilitate their respective risk management strategies. Those interest rate swaps are simultaneously economically hedged by offsetting derivatives that the Company executes with a third party, such that the Company minimizes its net risk exposure resulting from such transactions. As the interest rate derivatives associated with this program do not meet the strict hedge accounting requirements, changes in the fair value of both the customer derivatives and the offsetting derivatives are recognized in other income.

Risk Participation Agreements

The Company acquired, from Great Western Bank, risk participation agreements under which it assumed credit risk associated with a borrower’s performance related to derivative contracts. The Company only entered into these credit risk participation agreements in instances in which the Company was also a party to the related loan participation agreements for such borrowers. The Company manages its credit risk under risk participation agreements by monitoring the creditworthiness of the borrower, based on its normal credit review process.

The following table summarizes the fair values of our derivative instruments on a gross and net basis for the periods indicated. The derivative asset and liability balances are presented on a gross basis, prior to the application of bilateral collateral and master netting agreements, but after the variation margin payments with central clearing organizations have been applied as settlement, as applicable. Total derivative assets and liabilities are adjusted to account for the impact of legally enforceable master netting agreements that allow us to settle all derivative contracts with a single counterparty on a net basis and to offset the net derivative position with the related cash collateral. Securities collateral related to legally enforceable master netting agreements is not offset on the consolidated balance sheets.

There wasno unrealized fair value gain or loss on cash flow hedging derivative instruments recognized in other comprehensive income during the three months ended September 30, 2025 and an unrealized fair value loss of $1.9 million for the nine months ended September 30, 2025, and an unrealized fair value gain of $12.4 million and an unrealized fair value loss of $10.1 million for the three and the nine months ended September 30, 2024. All derivatives are carried at fair value in either other assets or other liabilities and all related cash flows are reported in the operating section of the consolidated statements of cash flows.

The tables below present the gross presentation, the effects of offsetting, and a net presentation of the Company’s derivatives as of the dates indicated:

Credit-risk-related Contingent Feature

The Company has agreements with certain of its derivative counterparties that contain a provision where if the Company defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender, then the Company could also be declared in default on its derivative obligations. In addition, the Company could be declared in default on its derivative obligations if repayment of the underlying indebtedness is accelerated by the lender due to the Company's default on the indebtedness.

The Company has agreements with certain of its derivative counterparties that contain a provision where if the Company fails to maintain its status as a well / adequately capitalized institution, then the counterparty could terminate the derivative positions and the Bank would be required to settle its obligations. Similarly, the Bank could be required to settle its obligations under certain of its agreements if specific regulatory events occur, such as a publicly issued prompt corrective action directive, cease and desist order, or a capital maintenance agreement that required the Bank to maintain a specific capital level. If the Bank had breached any of these provisions at September 30, 2025 or December 31, 2024 it could have been required to settle its obligations under the agreements at the termination value.

As of September 30, 2025 and December 31, 2024, the fair value of derivatives in a net liability position that have contingent features described above waszero. As of September 30, 2025 and December 31, 2024, the Company has minimum collateral posting thresholds with certain of its derivative counterparties and hasnot posted excess collateral. At September 30, 2025 and December 31, 2024, the Company had not breached any of the settlement acceleration provisions.

(6) LONG-TERM DEBT AND OTHER BORROWED FUNDS

A summary of long-term debt follows:

On August 15, 2025, the Company redeemed in full the outstanding $100.0 million of aggregate principal amount of 5.25% fixed-to-floating rate subordinated notes due 2030 (the “2020 Subordinated Notes”) set forth in the table above without any prepayment penalty, at a redemption price of 100% of the principal amount plus accrued and unpaid interest to, but excluding, August 15, 2025.

On June 10, 2025, the Company completed a public offering of $125.0 million fixed-to-floating rate subordinated notes due June 15, 2035 (the “Notes”). The Company may elect to redeem the Notes, in whole or in part, on any early redemption date which is any interest payment date on or after June 15, 2030 at a redemption price equal to 100% of the principal amount plus any accrued and unpaid interest. The Company may also redeem the Notes, in whole but not in part, upon certain conditions as defined in the indenture governing the Notes. Any early redemption of the Notes will be subject to regulatory approval to the extent then required under applicable laws or regulations, including capital regulations. Unamortized debt issuance costs of $2.8 million, as of September 30, 2025, are being amortized to maturity.

From and including the date of issuance to, but excluding, June 15, 2030, or earlier redemption date, the Notes will bear interest at an initial fixed rate of 7.625% per annum, payable semi-annually in arrears on June 15 and December 15 of each year, commencing on December 15, 2025. From and including June 15, 2030 to, but excluding, June 15, 2035, or earlier redemption date, the Notes will bear interest at a floating rate per annum equal to a benchmark rate, which is expected to be Three-Month Term Secured Overnight Financing Rate (“SOFR”) (as defined in the indenture governing the Notes), plus 398.0 basis points, payable quarterly in arrears on March 15, June 15, September 15 and December 15 of each year, commencing on September 15, 2030. Notwithstanding the foregoing, if the benchmark rate is less than zero, then the benchmark rate shall be deemed to be zero.

At September 30, 2025, the Company hadno outstanding FHLB borrowings as compared to $1,567.5 million of outstanding FHLB fixed rate borrowings at an average rate of 4.77% at December 31, 2024. As of September 30, 2025 and December 31, 2024, the Company had no other material outstanding borrowings classified as other borrowed funds.

At September 30, 2025, the Company has remaining available lines of credit with the FHLB of approximately $5,057.3 million, subject to collateral availability. The available line of credit and outstanding borrowings with the FHLB are collateralized by certain loans and securities with an advance equivalent collateral value of $5,061.2 million.

(7) CAPITAL STOCK

The Company’s common stock is traded on the NASDAQ stock market under the symbol “FIBK.”

As of September 30, 2025, the Company is authorized to issue an aggregate of 150,100,000 shares of capital stock, of which 150,000,000 shares are designated as common stock, and 100,000 are designated as preferred stock. Our common stock is uncertificated and hasone vote per share.

The Company had 103,967,257 shares and 104,585,964 shares of common stock outstanding as of September 30, 2025 and December 31, 2024, respectively, andno shares of preferred stock outstanding as of September 30, 2025 and December 31, 2024.

During the nine months ended September 30, 2025, the Company issued 39,058 restricted stock units to directors for their annual service on the Company's board of directors. The aggregate value of the restricted stock units issued to directors of $1.1 million is amortized into stock-based compensation expense in the accompanying consolidated statements of changes in stockholders’ equity over a one-year service-based period.

On August 28, 2025, the board of directors of the Company adopted a new stock repurchase program, pursuant to which the Company has been authorized to repurchase up to $150.0 million of its issued and outstanding shares of common stock on or prior to March 31, 2027, which is the expiration date of the program. Any repurchased shares will be returned to authorized but unissued shares of common stock, as permitted under applicable Delaware law.

During the three and nine months ended September 30, 2025,842,903 shares of common stock were repurchased under the new stock repurchase program at a total cost of $27.5 million or at a weighted average price of $32.58 per share. As of September 30, 2025, following these repurchases, approximately $122.5 million remained available for future purchases under the program. The additional stock repurchases during the three and nine months ended September 30, 2025 and 2024, were redemptions of vested restricted shares tendered in lieu of cash for payment of income tax withholding amounts by participants in the Company’s equity compensation plans.

(8) EARNINGS PER COMMON SHARE

Basic earnings per common share is calculated by dividing net income by the weighted average number of common shares outstanding during the period presented, excluding unvested restricted stock. Diluted earnings per share is calculated by dividing net income by the weighted average number of common shares determined for the basic earnings per share computation plus the dilutive effects of stock-based compensation using the treasury stock method.

The following table sets forth the computation of basic and diluted earnings per share for the periods presented:

The Company had 768,247 and 773,563 shares of unvested restricted stock as of September 30, 2025 and 2024, respectively, that were not included in the computation of diluted earnings per common share because performance conditions for vesting had not been met.

(9) REGULATORY CAPITAL

As of September 30, 2025 and December 31, 2024, the Company exceeded all capital adequacy requirements to which it is subject. Actual capital amounts and ratios for the Company and its subsidiary Bank, as of September 30, 2025 and December 31, 2024 are presented in the following tables:

(1) The capital conservation buffer is an additional 2.5% of the amount necessary to meet the minimum risk-based capital requirements for total, tier 1, and common equity tier 1 risk-based capital.

(2) The ratios to meet the requirements to be deemed “well-capitalized” are only applicable to FIB. However, the Company manages its capital position as if the requirements apply to the consolidated company and has presented the ratios as if they also applied on a consolidated basis.

(10) COMMITMENTS AND CONTINGENCIES

In the normal course of business, the Company is involved in various claims and litigation. The Company establishes accruals for legal matters when potential losses associated with the actions become probable and the amount of loss can be reasonably estimated. There is no assurance that the ultimate resolution of these matters will not significantly exceed the amounts that the Company has accrued. Accruals for legal matters are based on management’s best judgment after consultation with counsel and others. In the opinion of management, following consultation with legal counsel, the ultimate liability or disposition of all such claims and litigation is not expected to have a material adverse effect on the consolidated financial condition, results of operations, or liquidity of the Company.

As of September 30, 2025, the Company had commitments under construction contracts of $8.6 million.

Based on the specific terms stated in the agreements, the Company didnot have a significant amount of sold residential mortgage loans with recourse provisions still in effect as of September 30, 2025. The Company did not repurchase a significant amount of loans from secondary market investors under the terms of loan sales agreements during the period ended September 30, 2025. In the opinion of management, the risk of recourse and the subsequent requirement of loan repurchase to the Company is not significant, and accordingly no liabilities have been established related to such. In addition, the Company made various representations and warranties associated with the sale of loans. The Company has not incurred significant losses resulting from these provisions during the period ended September 30, 2025.

(11) FINANCIAL INSTRUMENTS WITH OFF-BALANCE SHEET RISK

In the normal course of business, the Company is a party to financial instruments with off-balance sheet risk to meet the financing needs of its clients. These financial instruments include commitments to extend credit and standby letters of credit. These instruments involve, to varying degrees, elements of credit and interest rate risk in excess of amounts recorded in the consolidated balance sheets. Commitments to extend credit are agreements to lend to a client so long as there is no violation of any condition established in the commitment contract. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. Standby letters of credit are conditional commitments issued by the Company to guarantee the performance of a client to a third party. The credit risk involved in issuing letters of credit is essentially the same as the credit risk involved in extending loan facilities to clients. The Company’s policy for obtaining collateral, and determining the nature of such collateral, is essentially the same as in the Company’s policies for making commitments to extend credit. The estimated fair value of the obligation undertaken by the Company in issuing standby letters of credit is included in accounts payable and accrued expenses in the Company’s consolidated balance sheets.

The following table presents our financial instruments with off-balance sheet risk, as well as the activity in the allowance for off-balance sheet credit losses related to those financial instruments:

(12) OTHER COMPREHENSIVE INCOME

The gross amounts of each component of other comprehensive loss and the related tax effects for the periods indicated are as follows:

The components of accumulated other comprehensive loss, net of related tax effects, are as follows:

(13) FAIR VALUE MEASUREMENTS

Fair value is defined as the price that would be received to sell an asset or be paid to transfer a liability in an orderly transaction between market participants at the measurement date. There is a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value.

The three levels of inputs to measure fair value are as follows:

•Level 1 - Quoted prices in active markets for identical assets or liabilities

•Level 2 - Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities

•Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of assets or liabilities

The methodologies used by the Company in determining the fair values of each class of financial instruments are based primarily on independent, market-based data to reflect a value that would be reasonably expected in an orderly transaction between market participants at the measurement date, and therefore, are classified within Level 2 of the valuation hierarchy. There have been no significant changes in the valuation techniques during the three and the nine months ended September 30, 2025 and 2024.

The Company’s policy is to recognize transfers between levels as of the end of the reporting period. Transfers in and out of Level 1, Level 2, and Level 3 are recognized on the actual transfer date. There wereno significant transfers between fair value hierarchy levels during the three and the nine months ended September 30, 2025 and 2024.

Further details on the methods used to estimate the fair value of each class of financial instruments above are discussed below:

Investment Debt Securities Available-for-Sale. The Company obtains fair value measurements for investment securities from an independent pricing service, and these securities are classified as level 2. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information, and the investment’s terms and conditions, among others. Vendors chosen by the Company are widely recognized vendors whose evaluations support the pricing functions of financial institutions, investment and mutual funds, and portfolio managers. If needed, a broker may be utilized to determine the reported fair value of investment securities. The Company also compares the reasonableness of the pricing quarterly through a validation process involving additional independent third parties.

Loans Held for Sale. Fair value measurements for residential mortgage loans held for sale are obtained from an independent pricing service and are classified as level 2. The fair value measurements consider observable data that may include binding contracts or quotes or bids from third party investors as well as loan level pricing adjustments. Commercial and agricultural loans held for sale are derived from quotes or bids from third party investors.

Interest Rate Collars: The fair values of interest rate collars are obtained from an independent third party and are classified as level 2. The values are determined using the market standard methodology of discounting the future expected cash receipts that would occur if variable interest rates fell below (rise above) the strike rate of the floors (caps). The variable interest rates used in the calculation of projected receipts on the collars are based on an expectation of future interest rates derived from observable market interest rate curves and volatilities. The Company also compares the reasonableness of the pricing quarterly through a validation process involving additional independent third parties.

Interest Rate Swap Contracts. Fair values for derivative interest rate swap contracts are obtained from an independent third party and are classified as level 2. The values are based upon the estimated amounts to settle the contracts considering current interest rates and are calculated using discounted cash flows that are observable, or that can be corroborated by observable market data. The inputs used to determine fair value include the United States Dollar – Secured Overnight Financing Rate (“SOFR”) and Prime forward curves to estimate variable rate cash inflows and SOFR to estimate the discount rate. The estimated variable rate cash inflows are compared to the fixed rate outflows and such difference is discounted to a present value to estimate the fair value of the interest rate swaps. The Company also compares the reasonableness of the pricing quarterly through a validation process involving additional independent third parties.

For purposes of potential valuation adjustments to our derivative positions, we evaluate both our credit risk and the credit risk of our counterparties. Accordingly, we have considered factors such as the likelihood of our default and the default of our counterparties, our net exposures and remaining contractual life, among other things, in determining if any fair value adjustments related to credit risk are required. The change in value of derivative assets and derivative liabilities attributable to credit risk was not significant during the reported periods.

Interest Rate Lock Commitments. Fair value measurements for interest rate lock commitments are obtained from an independent pricing service and are classified as level 2. The fair value measurements consider observable data that may include prices available from secondary market investors taking into consideration various characteristics of the loan, including the loan amount, interest rate, value of the servicing, and loan to value ratio, among other things. Observable data is then adjusted to reflect changes in interest rates, the Company’s estimated pull-through rate, and estimated direct costs necessary to complete the commitment into a closed loan net of origination, and processing fees collected from the borrower.

Forward Loan Sales Contracts. The fair value measurements for forward loan sales contracts are obtained from an independent pricing service and are classified as level 2. The fair value measurements consider observable data that includes sales of similar loans.

Deferred Compensation Plan Assets and Liabilities. The fair values of deferred compensation plan assets and liabilities are based primarily on quoted market prices for identical instruments traded in active markets at the measurement date and are classified as level 1. These investments are in the same funds and purchased in the same amounts as the participants’ selected investments, which represent the underlying liabilities to plan participants. Deferred compensation plan liabilities are recorded at amounts due to participants, based on the fair value of participants’ selected investments.

Financial assets and financial liabilities measured at fair value on a recurring basis are as follows:

Additionally, from time to time, certain assets are measured at fair value on a non-recurring basis. Adjustments to fair value generally result from the application of lower-of-cost-or-market accounting or write-downs of individual assets due to credit deterioration. The following table presents information about the Company’s assets and liabilities measured at fair value on a non-recurring basis with an adjustment during the period presented. The fair values may not be current as of the reporting date but represent fair values as of the most recent fair value change that occurred with the reporting period. Accordingly, carrying values may not equal the current fair value:

Collateral-dependent Loans. Collateral-dependent loans are reported at the fair value of the underlying collateral if repayment is expected solely from collateral. The collateral-dependent loans are reported at fair value through specific valuation allowance allocations. When it is determined that the fair value of a collateral-dependent loan is less than the recorded investment in the loan, an allowance for credit losses is recognized on the loan for the difference between the recorded investment and the fair value of the collateral less costs to sell. Collateral values are estimated using independent appraisals and management estimates of current market conditions. As of September 30, 2025 and December 31, 2024, the Company had collateral-dependent loans with a carrying value of $147.6 million and $97.6 million, respectively.

Long-lived Assets to be Disposed of by Sale. Long-lived assets to be disposed of by sale are carried at the lower of carrying value or fair value less estimated costs to sell. The fair values of long-lived assets to be disposed of by sale are based upon observable market data and management estimates of current market conditions. As of September 30, 2025, the Company had long-lived assets to be disposed of by sale with carrying and fair values aggregating $10.3 million. As of December 31, 2024, the Company had long-lived assets to be disposed of by sale with carrying and fair values aggregating $0.8 million.

The following table presents additional quantitative information about assets measured at fair value on a non-recurring basis and for which the Company has utilized Level 3 inputs to determine fair values:

The Company is required to disclose the fair value of financial instruments for which it is practical to estimate fair value. The methodologies for estimating the fair value of financial instruments that are measured at fair value on a recurring or non-recurring basis are discussed above. The methodologies for estimating the fair value of other financial instruments are discussed below. For financial instruments bearing a variable interest rate where no credit risk exists, it is presumed that recorded book values are reasonable estimates of fair value.

Financial Assets. Carrying values of cash, cash equivalents, and accrued interest receivable approximate fair values due to the liquid and/or short-term nature of these instruments. Fair values for investment securities held-to-maturity are obtained from an independent pricing service, which considers observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, trading levels, trade execution data, market consensus prepayment speeds, credit information, and the investment’s terms and conditions, among other things. Fair values of fixed rate loans and variable rate loans that reprice on an infrequent basis are estimated by discounting future cash flows using current interest rates at which similar loans with similar terms would be made to borrowers of similar credit quality using an exit price notion. Carrying values of variable rate loans that reprice frequently, and with no change in credit risk, approximate the fair values of these instruments. The estimated fair values for all loans are then reduced by the estimated life-of-the-loan aggregate credit losses in the loan portfolio.

Financial Liabilities. The fair values of demand deposits, savings accounts, securities sold under repurchase agreements, and accrued interest payable are the amounts that are payable on demand at the reporting date. The fair values of fixed-maturity certificates of deposit are estimated using external market rates that are currently offered for deposits that have similar remaining maturities. The fixed and floating rate subordinated debentures, floating rate subordinated term loan, other borrowed funds, fixed rate subordinated term debt, and capital lease obligation are estimated by discounting future cash flows using current rates for advances that have similar characteristics.

Commitments to Extend Credit and Standby Letters of Credit. The fair value of commitments to extend credit and standby letters of credit, based on fees currently charged to enter into similar agreements, is not significant.

The estimated fair values of financial instruments that are reported in the Company’s consolidated balance sheets, and are segregated by the level of the valuation inputs within the fair value hierarchy that are utilized to measure fair value, are as follows:

(14) RECENT AUTHORITATIVE ACCOUNTING GUIDANCE

ASU 2023-06, “Disclosure Improvements—Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative”In October 2023, the FASB issued ASU 2023-06, Disclosure Improvements—Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative that amends the ASC to incorporate certain disclosure requirements from SEC Release No. 33-10532 - Disclosure Update and Simplification that was issued in 2018. The effective date for each amendment will be the date on which the SEC’s removal of that related disclosure from Regulation S-X or Regulation S-K becomes effective, with early adoption prohibited. The Company does not anticipate the adoption of ASU 2023-06 will have a significant impact on the Company’s financial position, results of operations, or liquidity.

ASU 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures”In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures that require public business entities to annually disclose (1) specific categories in their rate reconciliation; (2) additional information for reconciling items that meet a quantitative threshold; (3) the amount of income taxes paid (net of refunds received) disaggregated by federal, state, and foreign taxes; (4) the amount of income taxes paid (net of refunds received) disaggregated by individual jurisdictions in which the income taxes paid that meet a quantitative threshold; (5) income (or loss) from continuing operations before income tax expense (or benefit) disaggregated between domestic and foreign; and (6) income tax expense (or benefit) from continuing operations disaggregated by federal, state, and foreign. The ASU eliminates the requirement to disclose the nature and estimate of the range of the reasonably possible change in the unrecognized tax benefits balance in the next 12 months and to disclose the cumulative amount of each type of temporary difference when a deferred tax liability is not recognized because of the exceptions to comprehensive recognition of deferred taxes related to subsidiaries and corporate joint ventures. For public business entities, the amendments are effective for annual periods beginning after December 15, 2024. The amendments should be applied on a prospective basis, but retrospective application is permitted. The adoption of ASU 2023-09 did not have a material impact on the Company’s financial position, results of operations, or liquidity.

ASU 2024-03, “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of income statement expenses”In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of income statement expenses that require public business entities to disclose additional information about specific expense categories in the notes to financial statements at interim and annual reporting periods. The amendments in this Update do not change or remove current expense disclosure requirements. The amendments in this Update are effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027. Early adoption is permitted. The amendments in this Update should be applied either (1) prospectively to financial statements issued for reporting periods after the effective date of this Update or (2) retrospectively to any or all prior periods presented in the financial statements. The Company is currently evaluating the impact of the standard and does not anticipate it will have a significant impact on the Company’s financial position, results of operations, or liquidity.

(15) SUBSEQUENT EVENTS

Subsequent events have been evaluated for potential recognition and disclosure through the date the Company’s financial statements were filed with the SEC. On October 28, 2025, the Company declared a quarterly dividend to common shareholders of $0.47 per share, to be paid on November 20, 2025 to shareholders of record as of November 10, 2025.

On October 7, 2025, the Company redeemed in full the trust securities of HF Financial Capital Trust III (“Trust XI”) at a redemption price of 100% of the principal amount of the issued and outstanding debt securities plus accrued and unpaid interest through October 6, 2025. The redemption included all of the outstanding debt securities ($5.2 million aggregate principal amount) which obligated the issuer trust to concurrently redeem all of the outstanding trust securities ($5.0 million aggregate principal amount of capital securities and $0.2 million aggregate principal amount of common securities).

On October 8, 2025, the Company redeemed in full the trust securities of HF Trust IV (“Trust XII”) at a redemption price of 100% of the principal amount of the issued and outstanding debt securities plus accrued and unpaid interest through October 7, 2025. The redemption included all of the outstanding debt securities ($7.2 million aggregate principal amount) which obligated the issuer trust to concurrently redeem all of the outstanding trust securities ($7.0 million aggregate principal amount of capital securities and $0.2 million aggregate principal amount of common securities).

On October 10, 2025, the Bank closed the previously disclosed transaction with Enterprise Bank & Trust (“Enterprise Bank”), a wholly-owned subsidiary of Enterprise Financial Services Corp, pursuant to which Enterprise Bank acquired twelve branches from the Bank, including approximately $645 million in deposits and certain commercially-oriented loans with outstanding balances of $305 million, and the owned real estate and fixed and other assets associated with the branches. The branches sold in the transaction included all of the Bank’s Kansas and Arizona locations, with ten branches in Arizona and two branches in Kansas. The Company anticipates recognizing an approximately $60 million pre-tax gain related to this transaction.

On October 16, 2025, the Bank entered into a Purchase and Assumption Agreement with Security First Bank (“Security First”) pursuant to which Security First will acquire from the Bank the eleven Nebraska branches previously identified. The Purchase and Assumption Agreement provides for the transfer by the Bank to Security First of the facilities and other associated assets of the branches, approximately $280 million in deposits, and loans with outstanding balances of roughly $70 million. Consummation of the transaction is subject to regulatory approvals and other customary conditions to closing. It is currently anticipated that the closing of the transaction will take place in early 2026.

On October 30, 2025, the Company announced the expected closure of four additional branches located in Nebraska in the first quarter of 2026.

As of October 31, 2025, the Company purchased 1.1 million shares of common stock during October 2025, for a total repurchase, under the stock repurchase program since the program was adopted on August 28, 2025 of approximately 1.9 million shares for a total approximate cost of $60.2 million.

No other undisclosed events requiring recognition or disclosure were identified.