MERCANTILE BANK CORP

NOTE1 - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Principles of Consolidation: The consolidated financial statements include the accounts of Mercantile Bank Corporation (“Mercantile”) and its subsidiaries, Mercantile Bank and Eastern Michigan Bank (collectively "our banks"), and Mercantile Community Partners LLC ("MCP"), and of Mercantile Insurance Center, Inc. (“our insurance company”), a subsidiary of Mercantile Bank, after elimination of significant intercompany transactions and accounts.

Mercantile hasfive separate business trusts: Mercantile Bank Capital Trust I, Firstbank Capital Trust I, Firstbank Capital Trust II, Firstbank Capital Trust III and Firstbank Capital Trust IV (“our trusts”). Our trusts were formed to issue trust preferred securities. We issued subordinated debentures to our trusts in return for the proceeds raised from the issuance of the trust preferred securities. Our trusts arenot consolidated, but instead we report the subordinated debentures issued to the trusts as liabilities.

Nature of Operations: Mercantile was incorporated on* July15,* 1997, to establish and own Mercantile Bank based in Grand Rapids, Michigan. Mercantile Bank began operations on* December15,* 1997. Mercantile Bank completed the merger of Firstbank Corporation, a Michigan corporation with approximately $1.5 billion in total assets and 46 branch locations, into Mercantile as of* June 1, 2014.On December 31, 2025,Mercantile completed the merger of Eastern Michigan Financial Corporation, and its wholly owned banking subsidiary, Eastern Michigan Bank, with approximately $572 million in total assets and 11 branch locations. Mercantile will operate for a period of time as atwo*-bank holding company. The newly acquired Eastern Michigan Bank will operate alongside Mercantile Bank until thefirst quarter of2027, at which time Mercantile plans to consolidate Eastern Michigan Bank into Mercantile Bank.

Mercantile is a financial holding company whose principal activity is the ownership and management of Mercantile Bank and Eastern Michigan Bank. Both Mercantile Bank and Eastern Michigan Bank are community-based financial institutions. Their primary deposit products are checking, saving, and term certificate accounts, and their primary lending products are commercial loans, residential mortgage loans, and instalment loans. Substantially all loans are secured by specific items of collateral, including business assets, real estate or consumer assets. Commercial loans are expected to be repaid from cash flow from operations of businesses. Real estate loans are secured by commercial or residential real estate. We haveno material foreign loans or significant overdraft balances. Our banks' loan accounts and retail deposits are primarily with customers located in the communities in which we have bank office locations. As an alternative source of funds, our banks have also issued certificates of deposit to depositors outside of their primary market areas.

Our insurance company acquired an existing shelf insurance agency effective* April 15, 2002.An Agency and Institution Agreement was entered into among our insurance company, Mercantile Bank and Hub International for the purpose of providing programs of mass marketed personal lines of insurance. Insurance product offerings include private passenger automobile, homeowners, personal inland marine, boat owners, recreational vehicle, dwelling fire, umbrella policies, small business and life insurance products, all of which are provided by and written through companies that have appointed Hub International as their agent. To date, we havenot* provided the insurance products noted above and currently haveno plans to do so.

We have evaluated subsequent events for potential recognition and/or disclosure through the date these financial statements were issued.

Use of Estimates: To prepare financial statements in conformity with accounting principles generally accepted in the United States of America, management makes estimates and assumptions based on available information. These estimates and assumptions affect the amounts reported in the financial statements and the disclosures provided, and actual results could differ. The allowance for credit losses and the fair value measurements are particularly subject to change.

Cash and Cash Equivalents and Cash Flow Reporting: Cash and cash equivalents include cash on hand, demand deposits with other financial institutions, short-term investments and federal funds sold. Cash flows are reported net for customer loan and deposit transactions, interest-earning deposits invested with other financial institutions and short-term borrowings with maturities of90 days or less.

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December 31, 2025

Debt Securities: Debt securities classified as held to maturity are carried at amortized cost when management has the positive intent and ability to hold them to maturity. Debt securities available for sale consist of bonds which might be sold prior to maturity due to a number of factors, including changes in interest rates, prepayment risks, yield, availability of alternative investments or liquidity needs. Debt securities classified as available for sale are reported at their fair value. For available for sale debt securities in an unrealized loss position, wefirst assess whether we intend to sell, or if it is more likely thannot that we will be required to sell the security before recovery of the amortized cost basis. If either of the criteria regarding intent or requirement to sell is met, the debt security’s amortized cost basis is written down to fair value through income with the establishment of an allowance. For debt securities available for sale that donot meet the aforementioned criteria, we evaluate whether any decline in fair value is due to credit loss factors. In making this assessment, we consider any changes to the rating of the security by a rating agency and adverse conditions specifically related to the issuer of the security, among other factors. If this assessment indicates that a credit loss exists, the present value of cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of the cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance is recorded for the credit loss, limited by the amount that the fair value is less than the amortized cost basis. Any impairment that hasnot been recorded through an allowance is recognized in other comprehensive income.

Changes in the allowance are recorded as provisions for (or reversals of) credit loss expense. Losses are charged against the allowance when the collectibility of an available for sale debt security is confirmed or when either of the criteria regarding intent or requirement to sell is met. At* December 31, 2025*, there wasno allowance related to the available for sale debt securities portfolio.

Interest income includes amortization of purchase premiums and accretion of discounts. Premiums and discounts on securities are amortized or accreted on the level-yield method without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated. Gains and losses on sales are recorded on the trade date and determined using the specific identification method.

Accrued interest receivable on available for sale debt securities totaling $5.5 million and $3.6 million at* December 31, 2025and2024*, respectively, was reported in other assets on the Consolidated Balance Sheets. Management has made the accounting policy election to exclude accrued interest receivable on available for sale securities from the estimate of credit losses as accrued interest is written off in a timely manner when deemed uncollectible.

Loans: Loans that we have the intent and ability to hold for the foreseeable future or until maturity or payoff are reported at the principal balance outstanding adjusted for partial charge-offs and the allowance, net of deferred loan fees and costs and purchase premiums and discounts. Interest income on loans is accrued over the term of the loans primarily using the simple interest method based on the principal balance outstanding. Accrued interest is included in other assets in the Consolidated Balance Sheets. Loan origination fees and certain direct costs incurred to extend credit are deferred and amortized over the term of the loan or loan commitment period as an adjustment to the related loan yield.

The* December 31, 2025,*acquisition of Eastern Michigan Bank resulted in the recognition of $1.5 million of net purchased loan discounts. Purchased loan discounts were measured at the time of acquisition based upon the difference between the initial amortized cost basis and the par value of the loan. The premiums and discounts will be amortized into interest income over the life of the loans.

Interest income is accrued on the unpaid principal balance. Loan origination fees, net of certain direct origination costs, are deferred and recognized in interest income using the level-yield method without anticipating prepayments. Net unamortized deferred loan costs amounted to $1.3 million and $2.2 million at* December 31, 2025and2024*, respectively.

Interest income on commercial loans and mortgage loans is discontinued at the time the loan is 90 days delinquent unless the loan is well-secured and in process of collection. Consumer and credit card loans are typically charged offno later than when they are 120 days past due. Past due status is based on the contractual terms of the loan. In all cases, loans are placed on nonaccrual or charged off at an earlier date if collection of principal and interest is considered doubtful. All interest accrued butnot received for loans placed on nonaccrual is reversed against interest income. Interest received on such loans is accounted for on the cash-basis or cost-recovery method, until qualifying for return to accrual. Loans are returned to accrual status when all the principal and interest amounts contractually due are brought current and future payments are reasonably assured.

Commercial Loan Participations: As part of our credit risk administration practices and to manage exposure limits, we engage in commercial loan participations with other financial institutions from time-to-time. In all instances, the commercial loans are participated at par withno loan yield adjustments; therefore,no gain or loss on sale, or servicing right, is recorded. We retain a large portion of the loan exposure and continue to service the lending relationship. Commercial loan participations aggregated $71.8 million and $48.6 million as of* December 31, 2025and2024*, respectively.

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Loans Held for Sale: Mortgage loans originated and intended for sale in the secondary market are carried at the lower of aggregate cost or fair value, as determined by outstanding commitments from investors. Net unrealized losses, if any, are recorded as a valuation allowance and charged to earnings. Mortgage loans held for sale are generally sold with servicing rights retained. Gains and losses on sales of mortgage loans are based on the difference between the selling price and the carrying value of the related mortgage loan sold, which is reduced by the cost allocated to the servicing right.

Year-end mortgage loans held for sale were as follows:

Mortgage Loan Derivatives: We enter into forward contracts and interest rate lock commitments in the ordinary course of business, which are accounted for as derivatives. The derivatives arenot designated as hedges and are carried at fair value. The net gain or loss on derivatives is included in mortgage banking activities in the Consolidated Statements of Income. The net balance of mortgage loan derivatives aggregated to an asset of $0.3 million as of* December 31, 2025*, and an asset of $0.1 million as of* December 31, 2024*.

Mortgage Banking Activities: Income derived from mortgage banking activities include the net gain on sale of mortgage loans, originated mortgage servicing rights, and servicing fee income net of mortgage servicing rights amortization expense. The net gain on sale of mortgage loans represents the premium received in excess of the unpaid principal balance plus net origination fees.

Originated mortgage loan servicing rights are recorded at fair value at the time of sale and amortized in proportion to, and over the period of, estimated net servicing revenues. At each period end, impairment is evaluated based on the fair value of the rights using groupings of the underlying mortgage loans as to interest rates. Any impairment of a grouping is reported as a valuation allowance. We have identifiedfour classes of mortgage servicing rights based on the initial term of the underlying mortgage loans:10 years,15 years,20 years and30 years. We distinguish between these classes based on the differing sensitivities to the change in value from changes in mortgage interest rates. Any impairment of a grouping is reported as a valuation allowance. Servicing fees are earned for servicing mortgage loans and are based on a contractual percentage of the outstanding principal or a fixed amount per loan and are recorded as income when earned.

Interest rate risk, prepayment risk and default risk are inherent in mortgage servicing rights valuations. Interest rate changes largely drive prepayment rates. Refinance activity generally increases as interest rates decline. A significant decrease in interest rates beyond expectation could cause a decline in the value of mortgage servicing rights. On the contrary, borrowers are less likely to refinance or prepay their mortgage loans if interest rates increase, which would extend the duration of the underlying mortgage loans and the associated mortgage servicing rights value would likely rise. Because of these risks, discount rates and prepayment speeds are used to estimate the fair value of mortgage servicing rights.

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Allowance for Credit Losses (“allowance”): The allowance is a valuation account that is deducted from the loans’ amortized cost basis to present the net amount expected to be collected on the loans. The allowance is increased by provision expense and decreased by charge-offs, net of recoveries of amounts previously charged-off. Loans are charged-off against the allowance when we believe the uncollectibility of a loan balance is confirmed. The allowance is measured on a collective pool basis when similar risk characteristics exist and on an individual basis when a loan exhibits unique risk characteristics that differentiate the loan from other loans within the loan segments. Loan segments are further discussed in Note3 - Loans and Allowance for Credit Losses.

The “remaining life methodology” is utilized for substantially all loan pools. This non-discounted cash flow approach projects an estimated future amortized cost basis based on current loan balance and repayment terms. Our historical loss rate is then applied to future loan balances at the instrument level based on remaining contractual life adjusted for amortization, prepayment and default to develop a baseline lifetime loss. The baseline lifetime loss is adjusted for changes in macroeconomic conditions over the reasonable and supportable forecast and reversion periods via a series of macroeconomic forecast inputs, such as gross domestic product, unemployment rates, interest rates, credit spreads, stock market volatility and property price indices, to quantify the impact of current and forecasted economic conditions on expected loan performance.

Reasonable and supportable economic forecasts have to be incorporated in determining expected credit losses. The forecast period represents the time frame from the current period end through the point in time that we can reasonably forecast and support entity and environmental factors that are expected to impact the performance of our loan portfolio. Ideally, the economic forecast period would encompass the contractual terms of all loans; however, the ability to produce a forecast that is considered reasonable and supportable becomes more difficult or* may**not* be possible in later periods. The contractual term generally excludes potential extensions, renewals and modifications.

Subsequent to the end of the forecast period, we revert to historical loan data based on an ongoing evaluation of each economic forecast in relation to then current economic conditions as well as any developing loan loss activity and resulting historical data. We arenot required to develop and use our own economic forecast model, and elect to utilize economic forecasts fromthird-party providers that analyze and develop forecasts of the economy for the entire United States at least quarterly.

During each reporting period, we also consider the need to adjust the historical loss rates as determined to reflect the extent to which we expect current conditions and reasonable and supportable economic forecasts to differ from the conditions that existed for the period over which the historical loss information was determined. These qualitative adjustments* may*increase or decrease our estimate of expected future credit losses.

Our qualitative factors include:

The estimation of future credit losses should reflect consideration of all significant factors that affect the collectibility of the loan portfolio at each evaluation date. While our methodology considers both the historical loss rates as well as the traditional qualitative factors, there* maybe instances or situations where additional qualitative factors need to be considered. Effective January 1, 2022,*we established a historical loss information factor to address the relatively low level of loan losses during the look-back period.

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Purchased loans are recorded at fair value at the time of acquisition and distinguished between purchased seasoned loans ("PSL"), purchased credit deteriorated loans ("PCD loans"), and non-seasoned new acquisitions. PSL are loans purchased at least90 days after its original origination date and without significant credit deterioration. PCD loans are acquired loans that have experienced a more-than-insignificant decline in credit quality since their origination. We considered all loans that were currently60 days or more past due, ever on nonaccrual status, had ever been past duethree or more times, consumer loans with borrower credit scores below600, or commercial loans rated monitor, special mention, substandard or doubtful to be PCD loans. There wereno non-seasoned new acquisition loans during2025, 2024 and2023.

PSL and PCD loans are accounted for using the gross-up approach prescribed in Accounting Standards Codification326, Financial Instruments - Credit Losses. The gross-up approach requires recognition of an allowance for the estimate of credit losses at the acquisition date. The allowance is recorded with an offsetting gross-up adjustment to the purchase price of the acquired financial asset.

Accrued interest receivable on loans totaling $17.5 million and $17.3 million as of* December 31, 2025and2024*, respectively, is included in other assets on the Consolidated Balance Sheets. We electednot to measure an allowance for accrued interest receivable and instead elected to reverse interest income on loans that are placed on nonaccrual status, which is generally when the loan becomes90 days past due, or earlier if we believe the collection of interest is doubtful. We believe this policy results in the timely reversal of uncollectible interest.

Identified problem loans, which exhibit characteristics (financial or otherwise) that could cause the loans to become nonperforming or require restructuring in the future, are included on an internal watch list. Senior management and the Board of Directors review this list regularly. In some cases, we* may*determine that an individual loan exhibits unique risk characteristics that differentiate the loan from other loans within the loan segments. In such cases, the loans are evaluated for expected credit losses on an individual basis and excluded from the collective evaluation. Specific reserve allocations of the allowance for credit losses are determined by analyzing the borrower’s ability to repay amounts owed and collateral deficiencies, among other things.

For individually analyzed loans that are deemed to be collateral dependent loans, we adopted the practical expedient to measure the allowance based on the fair value of collateral. The allowance is calculated on an individual loan basis based on the shortfall between the fair value of the loan’s collateral and its recorded principal balance. If the fair value of the collateral exceeds the recorded principal balance,no allowance is required. Fair value estimates of collateral on individually analyzed loans, as well as on foreclosed and repossessed assets, are reviewed periodically. We also have a process in place to monitor whether value estimates at each quarter-end are reflective of current market conditions. Our credit policies establish criteria for obtaining appraisals and determining internal value estimates. We* mayalso adjust outside and internal valuations based on identifiable trends within our markets, such as recent sales of similar properties or assets, listing prices and offers received. In addition, we may*discount certain appraised and internal value estimates to address distressed market conditions.

We are also required to consider expected credit losses associated with loan commitments over the contractual period in which we are exposed to credit risk on the underlying commitments unless the obligation is unconditionally cancellable by us. Any allowance for off-balance sheet credit exposures is reported as an other liability on our Consolidated Balance Sheets and is increased or decreased via other noninterest expense on our Consolidated Statement of Income. The calculation includes consideration of the likelihood that funding will occur and forecasted credit losses on commitments expected to be funded over their estimated lives. The allowance is calculated using the same aggregate reserve rates calculated for the funded portion of loans at the portfolio level applied to the amount of commitments expected to be funded.

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Transfers of Financial Assets: Transfers of financial assets are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is deemed to be surrendered when: (1) the assets have been isolated from our banks and put presumptively beyond the reach of the transferor and its creditors, even in bankruptcy or other receivership, (2) the transferee obtains the right (free of conditions that constrain it from taking advantage of that right) to pledge or exchange the transferred assets, and (3) our banks donot maintain effective control over the transferred assets through an agreement to repurchase them before their maturity or the ability to unilaterally cause the holder to return specific assets. Our transfers of financial assets are generally limited to commercial loan participations sold and residential mortgage loans sold in the secondary market.

Premises and Equipment: Land is carried at cost. Premises and equipment are stated at cost less accumulated depreciation. Buildings and related components are depreciated using the straight-line method with useful lives ranging from5 to33 years. Furniture, fixtures and equipment are depreciated using the straight-line method with useful lives ranging from3 to7 years. Maintenance, repairs and minor alterations are charged to current operations as expenditures occur and major improvements are capitalized. Premises and equipment are reviewed for impairment when events indicate their carrying amount* may**not* be recoverable based on future undiscounted cash flows. If impaired, the assets are recorded at the lower of carrying value or fair value.

Foreclosed Assets: Assets acquired through or in lieu of foreclosure are initially recorded at their estimated fair value net of estimated selling costs, establishing a new cost basis. If fair value subsequently declines, a valuation allowance is recorded through noninterest expense, as are collection and operating costs after acquisition. We hadno foreclosed assets as of* December 31, 2025and2024.*

Bank Owned Life Insurance: Our banks have purchased life insurance policies on certain key officers. Bank owned life insurance is recorded at its cash surrender value, or the amount that can be realized. Increases in the net cash surrender value of the policies, as well as insurance proceeds received, are recorded as noninterest income on the Consolidated Statements of Income and arenot subject to income taxes.

Goodwill: The acquisition method of accounting requires that assets and liabilities acquired in a business combination to be recorded at fair value as of the acquisition date. The valuation of assets and liabilities often involves estimates based onthird-party valuations or internal valuations based on discounted cash flow analyses or other valuation techniques, all of which are inherently subjective. This typically results in goodwill, the amount by which the cost of net assets acquired in a business combination exceeds their fair value, which is subject to impairment testing at least annually. We review goodwill for impairment on an annual basis as of* October 1or more often if events or circumstances indicate that it is more-likely-than-not that the fair value of a reporting unit is below its carrying value. Based on our annual impairment analysis of goodwill as of October 1,it was determined that the fair value was in excess of its respective carrying value as of October 1, 2025;therefore, goodwill was considerednot* impaired. Subsequent to the analysis of goodwill, on* December 31, 2025,we acquired Eastern Michigan Financial Corporation, resulting in the recognition of $23.2 million of goodwill. Goodwill recognized from the acquisition of Eastern Michigan Financial Corporation is further discussed in Note17* - Business Combinations.

Repurchase Agreements: Our banks sell certain securities under agreements to repurchase. The agreements are treated as collateralized financing transactions, with the obligations to repurchase the securities sold reflected as liabilities and the securities underlying the agreements remaining in assets in the Consolidated Balance Sheets.

Financial Instruments and Loan Commitments: Financial instruments include off-balance-sheet credit instruments, such as commitments to make loans and commercial letters of credit, issued to meet customer financing needs. The face amount for these items represents the exposure to loss, before considering customer collateral or ability to repay. Such financial instruments are recorded when they are funded. Instruments, such as standby letters of credit, that are considered financial guarantees are recorded at fair value. Reserves for unfunded commitments are recorded as an other liability on our Consolidated Balance Sheets.

Stock-Based Compensation: Compensation cost for equity-based awards is measured on the grant date based on the fair value of the award on that date and recognized over the requisite service period, net of estimated forfeitures. Fair value of stock option awards is estimated using a closed option valuation (Black-Scholes) model. Fair value of restricted stock awards is based upon the quoted market price of the common stock on the date of grant.

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NOTE1 – SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES(Continued)

Revenue from Contracts with Customers: We record revenue from contracts with customers in accordance with Accounting Standards Codification Topic606, “Revenue from Contracts with Customers” (“Topic606”). Under Topic606, we must identify the contract with a customer, identify the performance obligations in the contract, determine the transaction price, allocate the transaction price to the performance obligations in the contract, and recognize revenue when (or as) we satisfy a performance obligation. Significant revenue hasnot been recognized in the current reporting period that results from performance obligations satisfied in previous periods.

Our primary sources of revenue are derived from interest and dividends earned on loans, securities and other financial instruments that arenot within the scope of Topic606. We have evaluated the nature of our contracts with customers and determined that further disaggregation of revenue from contracts with customers into more granular categories beyond what is presented in the Consolidated Statements of Income wasnot necessary.

We generally satisfy our performance obligations on contracts with customers as services are rendered, and the transaction prices are typically fixed and charged either on a periodic basis (generally monthly) or based on activity. Because performance obligations are satisfied as services are rendered and the transaction prices are fixed, there is little judgment involved in applying Topic606 that significantly affects the determination of the amount and timing of revenue from contracts with customers.

The following table depicts our sources of noninterest income presented in the Consolidated Statements of Income for the years ended* December 31, 2025,*2024 and2023 that are scoped within Topic606:

Service Charges on Deposit and Sweep Accounts: We earn fees from deposit and sweep customers for account maintenance, transaction-based and overdraft services. Account maintenance fees, which relate primarily to monthly maintenance, are earned over the course of the month reflecting the period over which we satisfy the performance obligation. Transaction-based fees, which include services such as stop payment and returned item charges, are recognized at the time the transaction is executed as that is the point in time we fulfill the customer request. Service charges on deposit and sweep accounts are withdrawn from the customer account balance.

Credit and Debit Card Fees: We earn interchange income on our cardholder debit and credit card usage. Interchange income is primarily comprised of fees whenever our debit and credit cards are processed through card payment networks such as Visa. Interchange fees from cardholder transactions represent a percentage of the underlying transaction value and are recognized daily, concurrently with the transaction processing services provided to the cardholder.

Payroll Processing Fees: We earn fees from providing payroll processing services for our commercial clients. Fees are assessed for processing weekly or bi-weekly payroll files, reports and documents, as well as year-end tax-related files, reports and documents. Fees are recognized and collected as payroll processing services are completed for each payroll run and year-end processing activities.

Customer Service Fees: We earn fees by providing a variety of other services to our customers, such as wire transfers, check ordering, sales of cashier checks, and rentals of safe deposit boxes. Generally, fees are recognized and collected daily, concurrently with the point in time we fulfill the customer request. Safe deposit box rentals are on annual contracts, with fees generally earned at the time of the contract signing or renewal. Customer service fees are recorded as other noninterest income on our Consolidated Statements of Income.

Advertising Costs: Advertising costs are expensed as incurred.

Income Taxes: Income tax expense is the total of the current year income tax due or refundable, the change in deferred income tax assets and liabilities, and any adjustments related to unrecognized tax benefits. Deferred income tax assets and liabilities are recognized for the tax consequences of temporary differences between the carrying amounts and tax bases of assets and liabilities, computed using enacted tax rates applicable to future years. A valuation allowance, if needed, reduces deferred income tax assets to the amount expected to be realized.

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NOTE1 – SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES(Continued)

Fair Values of Financial Instruments: Fair values of financial instruments are estimated using relevant market information and other assumptions. Fair value estimates involve uncertainties and matters of significant judgment regarding interest rates, credit risk, prepayments and other factors, especially in the absence of broad markets for particular items. Changes in assumptions or in market conditions could significantly affect the estimates. The fair value estimates of existing on- and off-balance sheet financial instruments donot include the value of anticipated future business or the values of assets and liabilitiesnot considered financial instruments.

Earnings Per Share: Basic earnings per share is based on the weighted average number of common shares and participating securities outstanding during the period. Diluted earnings per share include the dilutive effect of additional potential common shares issuable under our stock-based compensation plans using the treasury stock method. Our unvested stock awards, which contain non-forfeitable rights to dividends whether paid or unpaid (i.e., participating securities), are included in the number of shares outstanding for both basic and diluted earnings per share calculations. In the event of a net loss, our unvested stock awards are excluded from the calculations of both basic and diluted earnings per share. There wereno dilutive shares outstanding during the years ended* December 31, 2025,2024 and2023. Weighted average common shares outstanding were 16,237,974,16,130,696, and 16,015,678 during the years ended December 31, 2025,*2024 and2023.

Comprehensive Income (Loss): Comprehensive income (loss) consists of net income and other comprehensive income (loss). Accumulated other comprehensive gain/(loss) includes unrealized gains and losses on securities available for sale. Accumulated other comprehensive gain/(loss) was comprised of the following as of* December 31, 2025,*2024 and2023:

Derivatives: Derivative financial instruments are recognized as assets or liabilities at fair value. The accounting for changes in the fair value of derivatives depends on the use of the derivatives and whether the derivatives qualify for hedge accounting. Used as part of our asset and liability management to help manage interest rate risk, our derivatives have historically generally consisted of interest rate swap agreements that qualified for hedge accounting. We donot use derivatives for trading purposes. Changes in the fair value of derivatives that are designated, for accounting purposes, as a hedge of the variability of cash flows to be received on various assets and liabilities and are effective are reported in other comprehensive income. They are later reclassified into earnings in the same periods during which the hedged transaction affects earnings and are included in the line item in which the hedged cash flows are recorded. If hedge accounting doesnot apply, changes in the fair value of derivatives are recognized immediately in current earnings as interest income or expense. We hadno derivative instruments designated as hedges as of* December 31, 2025and2024*.

Contingencies: Loss contingencies, including claims and legal actions arising in the ordinary course of business, are recorded as liabilities when the likelihood of loss is probable and an amount or range of loss can be reasonably estimated. We donot believe there are any such matters outstanding that would have a material effect on the financial statements.

Recent Accounting Changes Adopted: Accounting Standards UpdatedNo. 2025-08, Financial Instruments - Credit Losses (Topic326*): Purchased Loans.* This update expands the population of acquired financial instruments subject to the gross-up approach in Topic326. In accordance with the amendments in this update, loans (excluding credit cards) acquired without credit deterioration and deemed "seasoned" are purchased seasoned loans and accounted for using the gross-up approach at acquisition. This update takes effect for annual reporting periods beginning after* December 15, 2026,*and interim reporting periods within those annual reporting periods with adoption being applied prospectively to loans that are acquired on or after the initial application date. We have adopted the standard and included the required disclosures in our financial statements.

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NOTE2 – SECURITIES

The amortized cost and fair value of available for sale securities and the related pre-tax gross unrealized gains and losses recognized in accumulated other comprehensive gain/(loss) were as follows at year-end2025 and2024:

Securities with unrealized losses at year-end2025 and2024, aggregated by investment category and length of time that individual securities have been in a continuous loss position, are as follows:

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NOTE2 – SECURITIES (Continued)

We evaluate securities in an unrealized loss position at least quarterly. Consideration is given to the financial condition of the issuer, and the intent and ability we have to retain our investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value. For those debt securities whose fair value is less than their amortized cost basis, we also consider our intent to sell the security, whether it is more likely thannot that we will be required to sell the security before recovery and if we donot expect to recover the entire amortized cost basis of the security. In analyzing an issuer’s financial condition, we* may*consider whether the securities are issued by the federal government or its agencies, whether downgrades by bond rating agencies have occurred and the results of reviews of the issuer’s financial condition.

At* December 31, 2025*,607 debt securities with estimated fair values totaling $545 million had unrealized losses aggregating $36.9 million. At* December 31, 2024*,843 debt securities with estimated fair values totaling $680 million had unrealized losses aggregating $63.8 million. At* December 31, 2025*, unrealized losses aggregating $31.1 million were attributable to bonds issued or guaranteed by agencies of the U.S. federal government, while unrealized losses totaling $5.7 million were associated with bonds issued by state-based municipalities. After considering the issuers of the bonds and taking into account the fact thatno municipal issuer had been subject to a credit rating downgrade by bond credit rating agencies, we determined that the unrealized losses were due to changing interest rate environments. As we donot intend to sell our debt securities before recovery of their cost basis and we believe it is more likely thannot that we willnot be required to sell our debt securities before recovery of the cost basis,no unrealized losses are deemed to represent credit losses.

The amortized cost and fair values of debt securities at* December 31, 2025*, by maturity, are shown in the following table. The contractual maturity is utilized for U.S. Treasury notes and bonds, U.S. Government agency debt obligations and municipal bonds. Expected maturities* maydiffer from contractual maturities because borrowers mayhave the right to call or prepay obligations with or without call or prepayment penalties. Securitiesnot* due at a single maturity date, primarily mortgage-backed securities, are shown separately.

No securities were sold during the lastthree years.

Securities issued by the State of Michigan and all its political subdivisions had a combined amortized cost of $252 million and $219 million at* December 31, 2025* and* December 31, 2024*, respectively, with estimated market values of $249 million and $209 million at the respective dates. Securities issued by all other states and their political subdivisions had both a combined amortized cost and estimated fair value of $31.3 million as of* December 31, 2025*. We hadno securities issued by all other states and their political subdivisions as of* December 31, 2024.Total securities of any other specific issuer, other than the U.S. Government and its agencies and the State of Michigan and all its political subdivisions, didnot* exceed10% of shareholders’ equity.

The carrying value of U.S. Government agency debt obligations and mortgage-backed securities that are pledged to secure repurchase agreements was $232 million and $122 million at* December 31, 2025and2024*, respectively. The carrying value of U.S. Government agency debt obligations that are pledged to secure specific customer deposits was $12.6 million and $11.7 million as of* December 31, 2025and2024*, respectively.

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NOTE3 – LOANS AND ALLOWANCE FOR CREDIT LOSSES

Commercial loans are divided amongfive segments based primarily on collateral type, risk characteristics, and primary and secondary sources of repayment. These segments are then further stratified based on the commercial loan grade that is assigned using our standard loan grading paradigm. Retail loans are divided intoone oftwo groups based on risk characteristics and source of repayment. Our allowance for credit loss pools are consistent with those used for loan note disclosure purposes.

Our loan portfolio segments as of* December 31, 2025* were as follows:

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NOTE3 – LOANS AND ALLOWANCE FOR CREDIT LOSSES(Continued)

Year-end loans disaggregated by class of loan within the loan portfolio segments were as follows:

Concentrations within the loan portfolio were as follows at year end:

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An age analysis of past due loans is as follows as of* December 31, 2025*:

An age analysis of past due loans is as follows as of* December 31, 2024*:

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Nonaccrual loans as of* December 31, 2025* were as follows:

Nonaccrual loans represent the entire balance of collateral dependent loans. As of* December 31, 2025and2024*, all collateral dependent loans were secured by real estate, with the exception of those classified as commercial and industrial, which were secured by accounts receivable, inventory, and equipment. Interest income recognized on nonaccrual loans totaled $1.0 million in2025, $0.3 million in2024 and $0.2 million in2023, reflecting the collection of interest at the time of principal pay-off.

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Nonaccrual loans as of* December 31, 2024* were as follows:

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Nonaccrual loans as of* December 31, 2023* were as follows:

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Credit Quality Indicators. We utilize a comprehensive grading system for our commercial loans. All commercial loans are graded on aten grade rating system. The rating system utilizes standardized grade paradigms that analyze several critical factors such as cash flow, operating performance, financial condition, collateral, industry condition and management. All commercial loans are reviewed and graded at inception and, if appropriate, re-graded at various intervals thereafter. The risk assessment for retail loans is primarily based on the type of collateral.

Loans by credit quality indicators were as follows as of* December 31, 2025*:

Commercial credit exposure – credit risk profiled by internal credit risk grades:

Retail credit exposure – credit risk profiled by collateral type:

Loans by credit quality indicators were as follows as of* December 31, 2024*:

Commercial credit exposure – credit risk profiled by internal credit risk grades:

Retail credit exposure – credit risk profiled by collateral type:

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All commercial loans are graded using the following criteria:

The primary risk elements with respect to commercial loans are the financial condition of the borrower, the sufficiency of collateral, and timeliness of scheduled payments. We have a policy of requesting and reviewing periodic financial statements from commercial loan customers and employ a disciplined and formalized review of the existence of collateral and its value. The primary risk element with respect to each residential real estate loan and consumer loan is the timeliness of scheduled payments; loans90 days or more past due are considered nonperforming. We have a reporting system that monitors past due loans and have adopted policies to pursue creditors’ rights in order to preserve our collateral position.

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The following table reflects loan balances as of* December 31, 2025* based on year of origination:

There were lines of credit with principal balances of $0.7 million as of* December 31, 2024* that were converted to term loans during2025.

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The following table reflects loan balances as of* December 31, 2024* based on year of origination:

There were lines of credit with principal balances of $9.1 million as of* December 31, 2023* that were converted to term loans during2024.

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Mercantile Bank uses a migration to loss methodology to determine historical loss rates for commercial loans given the comprehensive loan grading process employed by Mercantile Bank for overtwo decades, while an open pool approach is best suited for retail loans given the smaller dollar size of the segments. A baseline loss rate is produced at each reporting date for each loan portfolio segment using bank-specific loan charge-off and recovery data over a defined historical look-back period. The look-back period represents the number of data periods that will be used to calculate a baseline loss rate for each loan portfolio segment. We determined that the look-back period commencing on* January 1, 2011through the reporting date was reasonable and appropriate for the calculation of historical loss rates for both December 31, 2025and2024*.

Mercantile Bank's historical loss rate is then applied to future loan balances at the instrument level based on remaining contractual life adjusted for amortization, prepayment and default to develop a baseline lifetime loss. Our prepayment speed assumptions are developed at the loan segment level based upon the consideration of all relevant data in which we believe will impact anticipated customer behavior including changes in interest rates, economic conditions, and underlying property valuations. For the commercial loan portfolio segments, we assumed a 2% prepayment speed as of both* December 31, 2025and2024* as we deemed there to beno considerable changes from historical experience. For the retail1-4 family mortgage and retail other consumer portfolios, we increased the prepayment speed from 7.8% as of* December 31, 2024* to 9.5% as of* December 31, 2025*. This increase shortened the average lives of the portfolios in which the loss rates were applied, resulting in a decrease to the allowance of $2.3 million. This change in assumption was driven by lower long-term interest rates and the compositions of the underlying portfolios.

During each reporting period, we also consider the need to adjust the historical loss rates as determined to reflect the extent to which we expect current conditions and reasonable and supportable economic forecasts to differ from the conditions that existed for the period over which the historical loss information was determined. These qualitative adjustments* mayincrease or decrease our estimate of expected future credit losses. As of December 31, 2025and2024*, we used aone-year reasonable and supportable economic forecast period, with asix-month straight-line reversion period for all loan segments. The economic forecasts used for our* December 31, 2025and2024* allowance calculations reflected allowance balance reductions of $0.3 million and $2.2 million, respectively.

The allowance for PSL and PCD loans acquired from the acquisition of Eastern Michigan Bank were measured at the loan segment level using proxy expected lifetime loss rates adjusted for qualitative risk factors, including lending management experience, loan review and audit results, asset quality and portfolio trends, loan portfolio growth, industry concentrations, trends in underlying collateral, external factors, and economic conditionsnot already captured.

Individual loans exhibiting unique risk characteristics, which differentiate the loans from other loans within the loan segments and are evaluated for expected credit losses on an individual basis, totaled $7.9 million and $7.4 million as of* December 31, 2025and2024*, respectively. Individual allowance allocations totaled $4.0 million and $2.2 million as of* December 31, 2025and2024*, respectively.

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December 31, 2025

The allowance for credit losses for the year ended* December 31, 2025* is as follows:

The allowance for credit losses for the year ended* December 31, 2024* is as follows:

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The allowance for credit losses for the year ended* December 31, 2023* is as follows:

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The following table presents the period-end amortized cost basis of modifications to borrowers experiencing financial difficulty by type of modification made during the year ended:

Loans listed under Term Extension were generally granted a series of short-term maturity extensions as part of the workout process and associated forbearance agreement.

The following table presents the period-end amortized cost basis of loans that have been modified in the pasttwelve months as of* December 31, 2025,*to borrowers experiencing financial difficulty by payment status and loan segment:

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NOTE4 - PREMISES AND EQUIPMENT, NET

Year-end premises and equipment were as follows:

Depreciation expense totaled $5.2 million for2025, and $6.0 million for both2024 and2023.

We enter into facility leases in the normal course of business. As of* December 31, 2025*, we were under lease contracts foreleven of our branch facilities. The leases have maturity dates ranging from* August, 2026through May, 2048,with a weighted average life of 9.4 years as of December 31, 2025*. All of our leases have multiple three- tofive-year extensions; however, these werenot factored in the lease maturities and weighted average lease term as it isnot reasonably certain we will exercise the options.

Leases are classified as either operating or finance leases at the lease commencement date, with all of our current leases determined to be operating leases. Lease expense for operating leases is recognized on a straight-line basis over the lease term. Right-of-use assets represent our right to use an underlying asset for the lease term, while lease liabilities represent our obligation to make lease payments arising from the lease. Right-of-use assets and lease liabilities are recognized at the lease commencement date at the estimated present value of lease payments over the lease term. We use our incremental borrowing rate, on a collateralized basis, at lease commencement to calculate the present value of lease payments. The weighted average discount rate for leases was 6.52% as of* December 31, 2025*.

The right-of-use assets, included inpremises and equipment, net on our Consolidated Balance Sheets, and the lease liabilities, included inother liabilities on our Consolidated Balance Sheets, totaled $3.9 million and $4.4 million as of* December 31, 2025*, and* December 31, 2024*, respectively. As permitted by applicable accounting standards, we have electednot to recognize short-term leases with original terms oftwelve months or less on our Consolidated Balance Sheets. Total operating lease expense associated with the leases aggregated $1.6 million, $1.6 million and $2.0 million in2025,2024 and2023, respectively.

Future lease payments were as follows as of* December 31, 2025*:

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NOTE5 – MORTGAGE LOAN SERVICING

Mortgage loans serviced for others arenot reported as assets on the Consolidated Balance Sheets. The year-end aggregate unpaid principal balances of mortgage loans serviced for others were as follows:

Custodial escrow balances, which are reported as deposits on the Consolidated Balance Sheets, maintained in connection with serviced loans were $14.5 million and $10.9 million as of* December 31, 2025* and2024, respectively.

Activity for capitalized mortgage loan servicing rights, which are reported as other assets on the Consolidated Balance Sheets, during2025 and2024 was as follows:

Mortgage servicing rights result from our mortgage loan origination activities. Late and ancillary fees, included as part of mortgage banking income and reported as noninterest income in the Consolidated Statements of Income, aggregated less than $0.1 million during2025 and2024.

We determined thatno valuation allowance was necessary as of* December 31, 2025* or* December 31, 2024*. The estimated fair value of mortgage servicing rights was $21.4 million and $21.0 million as of* December 31, 2025* and2024, respectively. The fair value of mortgage servicing rights is estimated using a valuation model that calculates the present value of estimated future net servicing cash flows, taking into consideration expected mortgage loan prepayment rates, discount rates, servicing costs and other economic factors, which are determined based on current market conditions. As of* December 31, 2025*, fair value was determined using a discount rate of 10.00%, a weighted average constant prepayment rate of 9.13%, depending on the stratification of the specific right, and a weighted average delinquency rate of 0.76%. As of* December 31, 2024*, fair value was determined using a discount rate of 10.50%, a weighted average constant prepayment rate of 7.81%, depending on the stratification of the specific right, and a weighted average delinquency rate of 0.68%.

The weighted average amortization period was 8.2 years and 8.7 years as of* December 31, 2025* and2024, respectively.

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NOTE6 – DEPOSITS

Deposits at year end are summarized as follows:

Out-of-area time deposits consist of deposits obtained from depositors outside of our primary market areas exclusively through deposit brokers.

The following table depicts the maturity distribution for time deposits at year end:

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NOTE6 – DEPOSITS(Continued)

Time deposits of more than*$250,000* totaled $551 million and $570 million at year-end2025 and2024, respectively.

Deposit overdrafts, which are reported as loans on the Consolidated Balance Sheets, totaled $0.6 million and $1.0 million as of* December 31, 2025* and2024, respectively.

NOTE7 – SECURITIES SOLD UNDER AGREEMENTS TO REPURCHASE

Information regarding securities sold under agreements to repurchase at year end is summarized below:

Securities sold under agreements to repurchase (“repurchase agreements”) generally have original maturities of less thanone year. Repurchase agreements are treated as financings, and the obligations to repurchase securities sold are reflected as liabilities on our Consolidated Balance Sheets. Repurchase agreements are secured by securities with an aggregate fair value equal to the aggregate outstanding balance of the repurchase agreements. The securities, which are included in securities available for sale on our Consolidated Balance Sheets, are held in safekeeping by a correspondent bank. Repurchase agreements are offered principally to certain large deposit customers.

NOTE8 - OTHER BORROWINGS

FHLBI bullet advances totaled $300 million at* December 31, 2025*, and were expected to mature at varying dates from* January 2026through June 2030,with fixed rates of interest from 0.90% to 4.50% and averaging 3.27%. FHLBI bullet advances totaled $360 million at December 31, 2024*, and were expected to mature at varying dates from* January 2025through January 2029,*with fixed rates of interest from 0.70% to 4.54% and averaging 3.10%.

Maturities of FHLBI bullet advances as of* December 31, 2025* were as follows:

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NOTE8 - OTHER BORROWINGS (Continued)

FHLBI amortizing advances totaled $26.2 million and $27.1 million as of* December 31, 2025and2024*, respectively, with an average fixed rate of 2.52% and maturities in2042. FHLBI amortizing advances are obtained periodically to assist in managing interest rate risk associated with certain longer-term fixed rate commercial loans, with annual principal payments that closely align with the scheduled amortization of the underlying commercial loans.

Scheduled principal payments on FHLBI amortizing advances as of* December 31, 2025* were as follows:

Each advance is payable at its maturity date, and is subject to a prepayment fee if paid prior to the maturity date. The advances are collateralized by residential mortgage loans,first mortgage liens on multi-family residential property loans,first mortgage liens on commercial real estate property loans, and substantially all other assets of Mercantile Bank under a blanket lien arrangement. Our borrowing line of credit as of* December 31, 2025* totaled $1.08 billion, with remaining availability based on collateral of $777 million.

On* December 15, 2021,we entered into Subordinated Note Purchase Agreements with certain institutional accredited investors pursuant to which we issued and sold $75.0 million in aggregate principal amount of 3.25% fixed-to-floating rate subordinated notes (“Notes”). The Notes have a stated maturity of January 30, 2032,and are redeemable by us at our option, in whole or in part, on or after January 30, 2027on any interest payment date at a redemption of price of 100% of the principal amount of the Notes being redeemed. The Notes arenot* subject to redemption at the option of the holder. The Notes will bear interest at a fixed rate of 3.25% per year until* January 29, 2027.Commencing on January 30, 2027and through the stated maturity date of January 30, 2032,the interest rate will reset quarterly at a variable rate equal to the then-current Three-Month Term SOFR plus 212 basis points. On December 15, 2021,*we injected $70.0 million of the issuance proceeds into Mercantile Bank as an increase to equity capital.

On* January 14, 2022,we issued an additional $15.0 million of Notes to certain institutional accredited investors, reflecting an expansion of the $75.0 million issuance completed on December 15, 2021.The additional $15.0 million issuance was completed on the same terms as the prior offering and under the existing indenture. On January 14, 2022,*we injected $15.0 million of the issuance proceeds into Mercantile Bank as an increase to equity capital.

Our unamortized debt issuance costs were $0.3 million and $0.7 million as of* December 31, 2025and2024*, respectively.

On* December 24, 2025,we entered into a credit agreement with U.S. Bank National Association for a $30.0 million term note. The term loan bears interest at an annual rate equal to 1.70% plus the greater of (a)zero percent (0.0%) and (b) theone*-month forward-looking term rate based on SOFR. Interest and principal are payable beginning* March 15, 2026,and on the same date of eachthird* month thereafter, plus a final payment equal to all unpaid interest and principal. Principal shall be paid in installments of $2.5 million each. The term loan matures on* December 24, 2028.*Mercantile is permitted to prepay the term note evidencing the term loan in full or in part at any time without indemnity, premium or penalty.

NOTE9 - FEDERAL INCOME TAXES

Pretax income is entirely related to domestic activities; we didnot have any foreign operations, tax expense or tax benefits. The consolidated income tax expense was as follows:

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NOTE9 - FEDERAL INCOME TAXES (Continued)

A reconciliation of the differences between the federal income tax expense recorded and the amount computed by applying the federal statutory rate to income before income taxes were as follows:

The statutory tax rate was 21% for2025,2024 and2023. We didnot record any state income taxes.

Significant components of deferred tax assets and liabilities, included in other assets on our Consolidated Balance Sheets, as of* December 31, 2025and2024* were as follows:

As of* December 31, 2025,we had net operating loss carryforwards of $7.3 million related to the acquisition of Eastern Michigan Financial Corporation. The ability to utilize the net operating loss in future periods is limited based on the value of Eastern Michigan Financial Corporation's value at the time of the ownership change and applicable federal rates. A valuation allowance related to deferred tax assets is required when it is considered more likely thannot* that all or part of the benefits related to such assets willnot be realized. We determined thatno valuation allowance was required at year-end2025 or2024.

We hadno unrecognized tax benefits at any time during2025 or2024. Should the accrual of any interest or penalties relative to unrecognized tax benefits be necessary, it is our policy to record such accruals in our income tax accounts; no such accruals existed at any time during2025 or2024. We areno longerno longer subject to examination by taxing authorities for years before2022.

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NOTE10 – STOCK-BASED COMPENSATION

Stock-based compensation plans are used to provide directors and employees with an increased incentive to contribute to our long-term performance and growth, to align the interests of directors and employees with the interests of our shareholders through the opportunity for increased stock ownership and to attract and retain directors and employees. Stock-based compensation, reported as noninterest expense in the Consolidated Statements of Income, totaled $3.5 million, $3.3 million and $3.4 million in2025, 2024 and2023, respectively. The Stock Incentive Plan of2023 that was approved by shareholders in* May, 2023.*

Under the Stock Incentive Plan of2023, incentive awards* mayinclude, but arenot* limited to, stock options, restricted stock, stock appreciation rights and stock awards. Incentive awards that are stock options or stock appreciation rights are granted with an exercise pricenot less than the closing price of our common stock on the date of grant. Price, vesting and expiration date parameters are determined by Mercantile’s Compensation Committee on a grant-by-grant basis.No payments are required from employees for restricted stock awards. The restricted stock awards granted during the years2023 through2025 fully vest afterthree years and, in the case of performance-based restricted stock issued to executive officers in2023 through2025, are subject to the attainment of pre-determined performance goals. At year-end2025, there were approximately 292,600 shares authorized for future incentive awards.

A summary of restricted stock activity during the year ended* December 31, 2025* is as follows:

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NOTE10 – STOCK-BASED COMPENSATION (Continued)

Of the restricted stock shares granted in2025 and2023, a total of 16,589 shares and 25,239 shares, respectively, are performance-based awards made to our Named Executive Officers at the target level and are subject to the attainment of pre-determined performance goals. There wereno shares granted in2024.

We periodically grant shares of common stock to our Corporate and Bank Board Directors for retainer payments with the related expense being recorded over the period of the Directors' service, as summarized below:

NOTE11 – RELATED PARTIES

Certain directors and executive officers of our banks, including their immediate families and companies in which they are principal owners, were loan customers of our banks. At year-end2025 and2024, our banks had $11.3 million and $20.4 million in loan commitments to directors and executive officers, of which $6.3 million and $7.8 million were outstanding at year-end2025 and2024, respectively, as reflected in the following table.

Related party deposits and repurchase agreements totaled $36.6 million and $17.9 million at year-end2025 and2024, respectively.

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NOTE12 – COMMITMENTS AND OFF-BALANCE-SHEET RISK

We are a party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of our customers. These financial instruments include commitments to extend credit and standby letters of credit. Loan commitments to extend credit are agreements to lend to a customer as long as there isno violation of any condition established in the contract. Standby letters of credit are conditional commitments issued by our banks to guarantee the performance of a customer to athird party. Commitments generally have fixed expiration dates or other termination clauses and* mayrequire payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts donot* necessarily represent future cash requirements.

These instruments involve, to varying degrees, elements of credit risk in excess of the amount recognized, if any, in the balance sheet. Our maximum exposure to loan loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit and standby letters of credit is represented by the contractual notional amount of those instruments. We use the same credit policies in making commitments and conditional obligations as we do for on-balance sheet instruments. Collateral, such as accounts receivable, securities, inventory, and property and equipment, is generally obtained based on management’s credit assessment of the borrower.

We are required to consider expected credit losses associated with loan commitments over the contractual period in which we are exposed to credit risk on the underlying commitments unless the obligation is unconditionally cancellable by us. Any allowance for off-balance sheet credit exposures is reported as an other liability on our Consolidated Balance Sheets and is increased or decreased via other noninterest expense on our Consolidated Statements of Income. The calculation includes consideration of the likelihood that funding will occur and forecasted credit losses on commitments expected to be funded over their estimated lives. The allowance is calculated using the same aggregate reserve rates calculated for the funded portion of loans at the portfolio level applied to the amount of commitments expected to be funded.

For commercial lines of credit, retail lines of credit and credit card average outstanding balances, we determined allowance requirements by calculating the difference between the average percent outstanding of the funded commitments over the past several years to actual percent outstanding at period end and applying the respective expected loss allocation factors to the difference as this difference represents the average of unfunded commitments we expect to eventually be drawn upon. For commitments to make loans, we determine an allowance by applying the expected loss allocation factor to the amount expected to fund. The calculated allowance aggregated $2.3 million and $1.0 million as of* December 31, 2025and2024*, respectively. We donot reserve for residential mortgage construction loans, as the loans are forone year or less and draws are governed by the receipt and satisfactory review of contractor and subcontractor sworn statements, lien waivers and title insurance company endorsements. Letters of credit are rarely drawn.

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NOTE12 – COMMITMENTS AND OFF-BALANCE-SHEET RISK(Continued)

At year-end2025 and2024, the rates on existing off-balance sheet instruments were substantially equivalent to current market rates, considering the underlying credit standing of the counterparties.

Our maximum exposure to credit losses for loan commitments and standby letters of credit outstanding at year end was as follows:

Commitments to make commercial loans generally reflect our binding obligations to existing and prospective customers to extend credit, including line of credit facilities secured by accounts receivable and inventory, and term loans secured by either real estate or equipment.

In most instances, commercial line of credit facilities have terms ranging from 12 to 24 months with floating rates tied to the Wall Street Journal Prime Rate or30-Day SOFR. Commercial term loans secured by real estate are generally at a floating rates tied to the Wall Street Journal Prime Rate or30-Day SOFR. Since thefourth quarter of2020, a fixed rate option for commercial term loans secured by real estate is generallynot offered for loans over*$2.5* million; instead, customers are offered participation in our back-to-back interest rate swap program to achieve a desired fixed rate. For loans under*$2.5* million, we offer a rate primarily equal to the commensurate cost of funds using FHLBI advance rates as a proxy and a credit spread as indicated by the credit rating we assign. Commercial term loans secured by real estate generally balloon within five years, with payments based on amortizations ranging from 10 to 25 years. Commercial term loans secured by non-real estate collateral are generally at a floating rate tied to the Wall Street Journal Prime Rate or30-Day SOFR, or a fixed rate primarily equal to the commensurate cost of funds using FHLBI advance rates as a proxy and a credit spread as indicated by the credit rating we assign, and generally mature and fully amortize within three toseven years.

The following standby letters of credit are considered financial guarantees under current accounting guidance. These instruments are carried at fair value as an other liability on our Consolidated Balance Sheets. Standby letters of credit are generally cross collateralized with the borrowers’ other loans with us, and are included in our borrower collateral analyses.

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NOTE13 – BENEFIT PLANS

We have a401(k) benefit plan that covers substantially all of our employees. The percent of our matching contributions to the401(k) benefit plan is determined annually by the Board of Directors. The matching contribution has been 5.00% since* April 1, 2018.Matching contributions, if made, are immediately vested. Our2025*,2024 and2023 matching401(k) contributions charged to expense were $2.8 million, $2.6 million and $2.3 million, respectively.

We have a deferred compensation plan in which all persons serving on the Board of Directors* maydefer all or portions of their annual retainer and meeting fees, with distributions to be paid upon termination of service as a director or specific dates selected by the director. We also have non-qualified deferred compensation programs in which selected officers maydefer all or portions of salary and bonus payments. The deferred amounts, which totaled $1.8 million and $1.3 million as of December 31, 2025and2024*, respectively, are categorized as other liabilities in the Consolidated Balance Sheets. Interest expense was $0.1 million during2025, and less than $0.1 million during2024 and2023.

The Mercantile Bank Corporation Employee Stock Purchase Plan of2025 is a non-compensatory plan intended to encourage full- and part-time employees of Mercantile and its subsidiaries to promote our best interests and to align employees’ interests with the interests of our shareholders by permitting employees to purchase shares of our common stock with 5% discount through regular payroll deductions. Shares are purchased on the last business day of each calendar quarter at a price equal to the lower of 95% of the closing price of our common stock reported on The Nasdaq Stock Market on thefirst business day of each quarter and last business day of the quarter. A total of 200,000 shares of common stock* maybe issued under the existing plan; however, the number of shares maybe adjusted to reflect any stock dividends and other changes in our capitalization. The number of shares issued totaled 2,356 in2025*. As of* December 31, 2025*, there were approximately 198,000 shares available under our current plan.

The Mercantile Bank Corporation Employee Stock Purchase Plan of2014 was a non-compensatory plan intended to encourage full- and part-time employees of Mercantile and its subsidiaries to promote our best interests and to align employees’ interests with the interests of our shareholders by permitting employees to purchase shares of our common stock through regular payroll deductions. The number of shares issued totaled 598 and 1,194 in2025 and2024, respectively.

NOTE14 – DERIVATIVES AND HEDGING ACTIVITIES

We are exposed to certain risks arising from both business operations and economic conditions. We principally manage the exposure to a wide variety of operational risks through core business activities. Economic risks, including interest rate, liquidity and credit risk, are primarily administered via the amount, sources and duration of assets and liabilities. Derivative financial instruments* may*also be used to assist in managing economic risks.

Derivativesnot designated as hedges arenot speculative and result from a service provided to certain commercial loan borrowers. We execute interest rate swaps with commercial banking customers desiring longer-term fixed rate loans, while simultaneously entering into interest rate swaps with correspondent banks to offset the impact of the interest rate swaps with the commercial banking customers. The net result is the desired floating rate loans and a minimization of the risk exposure of the interest rate swap transactions. These swap agreements are cross collateralized with the underlying loans.

As the interest rate swaps associated with this program donot meet the strict hedge accounting requirements, changes in the fair value of both the commercial banking customer interest rate swaps and the offsetting interest rate swaps with the correspondent banks are recognized directly to earnings. Fees paid to us by the correspondent banks are recognized as noninterest income on our Consolidated Statements of Income on the settlement date.

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NOTE14 – DERIVATIVES AND HEDGING ACTIVITIES (Continued)

The fair values of derivative instruments as of* December 31, 2025*, are reflected in the following table.

The effect of interest rate swaps that arenot designated as hedging instruments resulted in expense of less than $0.1 million during the year ended* December 31, 2025* that was recorded in other noninterest expense on our Consolidated Statement of Income. We have master netting arrangements with our correspondent banks that allow us to net receivables and payables. The netting agreement also allows us to net related cash collateral received and transferred up to the fair value exposure amount. We have elected tonot offset these transactions on the Consolidated Balance Sheets. The netting of derivative instruments as of* December 31, 2025* is presented in the following table.

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NOTE14 – DERIVATIVES AND HEDGING ACTIVITIES (Continued)

The fair values of derivative instruments as of* December 31, 2024*, are reflected in the following table.

The effect of interest rate swaps that arenot designated as hedging instruments resulted in expense of less than $0.1 million during the year ended* December 31, 2024* that was recognized in other noninterest expense on our Consolidated Statement of Income. The netting of derivative instruments as of* December 31, 2024* is presented in the following table.

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NOTE15 – FAIR VALUES OF FINANCIAL INSTRUMENTS

Carrying amount, estimated fair value and level within the fair value hierarchy of financial instruments were as follows at year end:

Carrying amount is the estimated fair value for cash and cash equivalents, FHLBI stock, accrued interest receivable and payable, noninterest-bearing checking accounts and securities sold under agreements to repurchase. Security fair values are based on market prices or dealer quotes, and ifno such information is available, on the rate and term of the security and information about the issuer. Fair value for loans is based on an exit price model as required by ASU2016-01, taking into account inputs such as discounted cash flows, probability of default and loss given default assumptions. Fair value for deposit accounts other than noninterest-bearing checking accounts is based on discounted cash flows using current market rates applied to the estimated life. The fair values of subordinated debentures, subordinated notes, and FHLBI advances are based on current rates for similar financing. The fair values of interest rate swaps are based on discounted cash flows using forecasted yield curves, along with insignificant unobservable inputs, such as borrower credit spreads. The fair value of other off-balance sheet items is estimated to be nominal.

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NOTE16 – FAIR VALUE MEASUREMENTS

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. A fair value measurement assumes that the transaction to sell the asset or transfer the liability occurs in the principal market for the asset or liability, or in the absence of a principal market, the most advantageous market for the asset or liability. The price of the principal (or most advantageous) market used to measure the fair value of the asset or liability isnot adjusted for transaction costs. An orderly transaction is a transaction that assumes exposure to the market for a period prior to the measurement date to allow for marketing activities that are usual and customary for transactions involving such assets and liabilities; it isnot a forced transaction. Market participants are buyers and sellers in the principal market that are (i) independent, (ii) knowledgeable, (iii) able to transact and (iv) willing to transact.

We are required to use valuation techniques that are consistent with the market approach, the income approach and/or the cost approach. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets and liabilities. The income approach uses valuation techniques to convert future amounts, such as cash flows or earnings, to a single present amount on a discounted basis. The cost approach is based on the amount that currently would be required to replace the service capacity of an asset (replacement cost). Valuation techniques should be consistently applied. Inputs to valuation techniques refer to the assumptions that market participants would use in pricing the asset or liability. Inputs* may*be observable, meaning those that reflect the assumptions market participants would use in pricing the asset or liability developed based on market data obtained from independent sources, or unobservable, meaning those that reflect our own estimates about the assumptions market participants would use in pricing the asset or liability based on the best information available in the circumstances. In that regard, we utilize a fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. The fair value hierarchy is as follows:

Level1: Quoted prices (unadjusted) for identical assets or liabilities in active markets that we have the ability to access as of the measurement date.

Level2: Significant other observable inputs other than Level1 prices such as quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that arenot active; or other inputs that are observable or can be derived from or corroborated by observable market data by correlation or other means.

Level3: Significant unobservable inputs that reflect our own estimates about the assumptions that market participants would use in pricing an asset or liability.

The following is a description of our valuation methodologies used to measure and disclose the fair values of our financial assets and liabilities on a recurring or nonrecurring basis:

Securities available for sale. Securities available for sale are recorded at fair value on a recurring basis. Fair value measurement is based on quoted prices, if available. If quoted prices arenot available, fair values are measured using independent pricing models. Level2 securities include U.S. Government agency debt obligations, mortgage-backed securities issued or guaranteed by U.S. Government agencies, and municipal general obligation and revenue bonds. Level3 securities include bonds issued by certain relatively small municipalities located within our markets that have very limited marketability due to their size and lack of ratings from a recognized rating service. We carry these bonds at historical cost, which we believe approximates fair value, unless our periodic financial analysis or other information that becomes known to us necessitates an impairment. There wasno such impairment as of* December 31, 2025* or2024. We haveno Level1 securities available for sale.

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Derivatives. We measure fair value utilizing models that use primarily market observable inputs, such as forecasted yield curves. Insignificant unobservable inputs, such as borrower credit spreads, are also utilized.

Mortgage loans held for sale. Mortgage loans originated and intended for sale in the secondary market are carried at the lower of aggregate cost or market, as determined by outstanding commitments from investors, and are measured on a nonrecurring basis. Fair value is based on independent quoted market prices, where applicable, or the prices for other mortgage whole loans with similar characteristics. As of* December 31, 2025and2024*, we determined the fair value of our mortgage loans held for sale to be $17.3 million and $16.0 million, respectively.

Loans. We donot record loans at fair value on a recurring basis. However, from time to time, we record nonrecurring fair value adjustments to collateral dependent loans to reflect partial write-downs or specific reserves that are based on the observable market price or current estimated value of the collateral. These loans are reported in the nonrecurring table below at initial recognition of significant borrower distress and on an ongoing basis until recovery or charge-off. The fair values of distressed loans are determined using either the sales comparison approach or income approach; respective unobservable inputs for the approaches consist of adjustments for differences between comparable sales and the utilization of appropriate capitalization rates.

Foreclosed assets. At time of foreclosure or repossession, foreclosed and repossessed assets are adjusted to fair value less costs to sell upon transfer of the loans to foreclosed and repossessed assets, establishing a new cost basis. We subsequently adjust estimated fair value of foreclosed assets on a nonrecurring basis to reflect write-downs based on revised fair value estimates. The fair values of parcels of other real estate owned are determined using either the sales comparison approach or income approach; respective unobservable inputs for the approaches consist of adjustments for differences between comparable sales and the utilization of appropriate capitalization rates.

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Assets and Liabilities Measured at Fair Value on a Recurring Basis

The balances of assets and liabilities measured at fair value on a recurring basis as of* December 31, 2025* are as follows:

There wereno sales or purchases of Level3 during2025. The $0.4 million reduction in Level3 municipal general obligation bonds during2025 reflects the transfer to Level2 due to a change in observable inputs.

The balances of assets and liabilities measured at fair value on a recurring basis as of* December 31, 2024* are as follows:

There wereno sales, purchases or transfers in or out of Level3 during2024. The $0.1 million reduction in Level3 municipal general obligation bonds during2024 reflects the scheduled maturities of such bonds.

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Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis

The balances of assets and liabilities measured at fair value on a nonrecurring basis as of* December 31, 2025* are as follows:

The balances of assets and liabilities measured at fair value on a nonrecurring basis as of* December 31, 2024* are as follows:

The carrying values are based on the estimated value of the property or other assets. Fair value estimates of collateral on collateral dependent loans and foreclosed assets are review periodically. Our credit policies establish criteria for obtaining appraisals and determining internal value estimates. We* mayalso adjust outside appraisals and internal evaluations based on identifiable trends within our markets, such as sales of similar properties or assets, listing prices and offers received. In addition, we maydiscount certain appraised and internal value estimates to address current distressed market conditions. Typically, for real estate dependent loans and foreclosed assets, we assign a discount factor range of 25% to 50%. During2025,* weighted average discount factors of 40.9% and 25.8% were used for commercial-related and residential-related properties, respectively.

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NOTE17 – BUSINESS COMBINATIONS

On* December 31, 2025,Mercantile completed its acquisition of Eastern Michigan Financial Corporation, and its wholly owned banking subsidiary, Eastern Michigan Bank, in accordance with the Agreement and Plan of Merger, as amended (the "Merger Agreement") by and between Mercantile, Eastern Michigan Financial Corporation, and Shamrock Merger Sub LLC, a wholly-owned special purpose subsidiary of Mercantile (“Merger Sub”) entered into on July 22, 2025.Pursuant to the Merger Agreement, Eastern Michigan Financial Corporation merged with and into Merger Sub, with Merger Sub continuing as the surviving entity (the “Merger”). Immediately following the Merger, and also effective as of December 31, 2025,Merger Sub merged with and into Mercantile, with Mercantile continuing as the surviving entity. The newly acquired Eastern Michigan Bank will operate alongside Mercantile Bank until thefirst* quarter of2027, at which time Mercantile plans to consolidate Eastern Michigan Bank into Mercantile Bank.

Mercantile accounted for the Eastern Michigan Financial Corporation acquisition as a business combination using the acquisition method of accounting in accordance with ASC805, Business Combinations ("ASC805"). ASC805 requires assets purchased and liabilities assumed to be recorded at their respective fair values as of the date of acquisition. Mercantile determined the fair value of loans, core deposit intangibles, mortgage servicing rights, time deposits, and real property with the assistance ofthird-party valuations and appraisals. The following table summarizes the preliminary fair value of the total consideration transferred and the fair value of identifiable assets acquired, and liabilities assumed as of the effective date of the transaction:

As permitted by ASC805, the above preliminary estimates* maybe refined during the measurement period (which cannot exceedone* year from the Merger date), to reflect any new information obtained about facts and circumstances existing at the Merger date. Any changes in the above preliminary estimates will be recognized in the period identified.

The following table presents supplemental pro-forma information as if the acquisition had occurred at the beginning of2024. The unaudited pro forma information includes adjustments for interest income on loans acquired, amortization of intangibles arising from the transaction, depreciation expense on property acquired, interest expenses on deposits acquired, and the related income tax effects. The pro forma financial information isnot necessarily indicative of the results of operations that would have occurred had the transaction effected on the assumed dates.

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NOTE18 – VARIABLE INTEREST ENTITIES

Variable interest entities ("VIEs") are entities that either have a total equity investment that is insufficient to permit the entity to finance its activities without additional subordinated financial support or whose equity investors lack the characteristics of a controlling financial interest (i.e., ability to make significant decisions, through voting rights, right to receive the expected residual returns of the entity, and obligations to absorb the expected losses of the entity). Variable interest entities can be structured as corporations, trusts, partnerships, or other legal entities. We have relationships with certain variable interest entities related to the issuance of trust preferred securities and our tax credit investments.

We have five business trusts that are wholly owned subsidiaries of Mercantile, four of which were assumed by Mercantile in conjunction with the Firstbank Corporation merger in2014. A fair value discount of $15.0 million was recorded at the time of the merger, which is being amortized at $0.7 million annually over the following 21.5 years,11 of which are remaining. Each of the trusts was solely formed to issue preferred securities that were sold in private sales. Through a small common stock investment, we own 100% of the voting equity shares of each trust. The proceeds from the preferred securities and common stock sales were used by the trusts to purchase Floating Rate Notes issued by Mercantile. The rates of interest, interest payment dates, call features and maturity dates of each Floating Rate Note are identical to its respective Preferred Securities. The net proceeds from the issuance of the Floating Rate Notes were used for a variety of purposes, including contributions to Mercantile Bank as capital to provide support for asset growth and the funding of stock repurchase programs and certain acquisitions.

The assets, liabilities, operations and cash flows of each trust are solely related to the issuance, administration and repayment of the preferred securities held bythird-party investors. We fully and unconditionally guarantee the obligations of each trust and are obligated to redeem the junior subordinated debentures upon maturity. We donot consolidate the trusts as we arenot the primary beneficiary of these entities because our wholly-owned and indirect wholly-owned statutory subsidiaries donot have the power to direct the activities of the variable interest entity that most significantly impact the variable interest entity’s economic performance and donot have an obligation to absorb losses or the right to receive benefits that could potentially be significant to the variable interest entity. As such, we donot have a controlling financial interest in the variable interest entities.

The only significant assets of our trusts are the Floating Rate Notes, and the only significant liabilities of our trusts are the Preferred Securities. The Floating Rate Notes are categorized on our Consolidated Balance Sheets as subordinated debentures and the interest expense is recorded on our Consolidated Statements of Income under interest expense on other borrowings.

On* January 26, 2016,*we closed on a repurchase of trust preferred securities that were auctioned as part of a pooled collateralized debt obligation (“Fund”). The Fund owned $11.0 million of the $32.0 million in trust preferred securities that had been issued by Mercantile Bank Capital Trust I. The $11.0 million in trust preferred securities was retired upon the repurchase, resulting in a commensurate reduction in the related Floating Rate Junior Subordinate Note, leaving $21.0 million outstanding.

The following table depicts ourfive business trusts as of* December 31, 2025*:

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NOTE18 – VARIABLE INTEREST ENTITIES (Continued)

MCP makes equity investments as a limited liability member in affordable housing projects utilizing the Low-Income Housing Tax Credit (“LIHTC”) pursuant to Section42 of the Internal Revenue Code. Mercantile Bank also invests in multi-investor funds, which in turn invest in projects similar to that of MCP. The purpose of these investments is to achieve a satisfactory return on capital and to support our banks' community reinvestment initiatives. The activities of the limited liability entities include the identification, development, and operation of multi-family housing that is leased to qualifying residential tenants generally within our banks' primary geographic regions. MCP also makes equity investments via special purpose investment entities as a limited liability member in entities that receive Historic Tax Credits (“HTC”) pursuant to Section47 of the Internal Revenue Code. The purpose of these investments is the rehabilitation of historic buildings with the tax credits provided to incent private investment in the historic cores of cities and towns.

The LIHTC and HTC investment entities are considered VIEs as MCP, or our banks, whomever is the holder of the equity investment at risk, doesnot have the ability to direct the activities that most significantly affect the performance of the entity through voting rights or similar rights. MCP, or our banks, could absorb losses that are significant to the underlying entities as it has a risk of loss for its capital contributions and funding commitments to each. The general partners, or managing members, are considered the primary beneficiaries as managerial functions give them the power to direct the activities that most significantly impact the entities’ economic performances, and the managing members are exposed to all losses beyond MCP’s, or our banks', initial capital contributions and funding commitments. We account for these entities using the proportional amortization method with the investment assets amortized in proportion to the income tax credits received in the current period as compared to the total income tax credit benefits expected to be received over the life of the investment.

Equity investments as a limited liability member in LIHTC and HTC investment entities, reported asother assets in the Consolidated Balance Sheets, totaled $51.5 million and $38.9 million as of* December 31, 2025and2024*, respectively. Unfunded capital commitments, reported as other liabilities in the Consolidated Financial Statements, totaled $31.1 million and $34.4 million as of* December 31, 2025* and2024, respectively.

The following table summarizes quantitative information about our involvement in unconsolidated variable interest entities at year end:

As of* December 31, 2025,*our expected payments for unfunded contributions related to investments in tax credit equity investments were as follows:

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NOTE19 - REGULATORY MATTERS

We are subject to regulatory capital requirements administered by federal banking agencies. Capital adequacy guidelines and prompt corrective action regulations involve quantitative measures of assets, liabilities, and certain off-balance sheet items calculated under regulatory accounting practices. Capital amounts and classifications are also subject to qualitative judgments by regulators about components, risk weightings, and other factors, and the regulators can lower classifications in certain cases. Failure to meet various capital requirements can initiate regulatory action that could have a direct material effect on the financial statements.

The prompt corrective action regulations providefive classifications, including well capitalized, adequately capitalized, undercapitalized, significantly undercapitalized, and critically undercapitalized, although these terms arenot used to represent overall financial condition. If an institution isnot well capitalized, regulatory approval is required to accept brokered deposits. Subject to limited exceptions,no institution* maymake a capital distribution if, after making the distribution, it would be undercapitalized. If an institution is undercapitalized, it is subject to close monitoring by its principal federal regulator, its asset growth and expansion are restricted, and plans for capital restoration are required. In addition, further specific types of restrictions maybe imposed on the institution at the discretion of the federal regulator. At year-end2025* and2024, our banks were in the well capitalized category under the regulatory framework for prompt corrective action. There areno conditions or events since* December 31, 2025* that we believe have changed our banks' categorizations.

Under the final BASEL III capital rules that became effective on* January 1, 2015,there is a requirement for a common equity Tier1* capital conservation buffer of 2.5% of risk-weighted assets which is in addition to the other minimum risk-based capital standards in the rule. Institutions that donot meet this required capital buffer will become subject to progressively more stringent limitations on the percentage of earnings that can be paid out in cash dividends or used for stock repurchases and on the payment of discretionary bonuses to senior executive management. The capital buffer requirement was phased in overthree years beginning in2016. The capital buffer requirement raised the minimum required common equity Tier1 capital ratio to 7.0%, the Tier1 capital ratio to 8.5% and the total capital ratio to 10.5% on a fully phased-in basis on* January 1, 2019.We believe that, as of December 31, 2025*, our banks meet all capital adequacy requirements under the BASEL III capital rules on a fully phased-in basis.

Federal and state banking laws and regulations place certain restrictions on the amount of dividends our banks can transfer to Mercantile and on the capital levels that must be maintained. At year-end2025, under the most restrictive of these regulations, Mercantile Bank could distribute $12.0 million and Eastern Michigan Bank could distribute $4.5 million to Mercantile as dividends without prior regulatory approval. Our and the ability of our banks to pay cash and stock dividends is subject to limitations under various laws and regulations and to prudent and sound banking practices. On* January 16, 2025,our Board of Directors declared a cash dividend on our common stock in the amount of $0.37 per share that was paid on March 19, 2025,to shareholders of record as of March 7, 2025.On April 17, 2025,our Board of Directors declared a cash dividend on our common stock in the amount of $0.37 per share that was paid on June 18, 2025,to shareholders of record as of June 6, 2025.On July 17, 2025,our Board of Directors declared a cash dividend on our common stock in the amount of $0.38 per share that was paid on September 17, 2025,to shareholders of record as of September 5, 2025.On October 16, 2025,our Board of Directors declared a cash dividend on our common stock in the amount of $0.38 per share that was paid on December 17, 2025,to shareholders of record as of December 5, 2025.*

As of* December 31, 2025*, we had the ability to repurchase up to $6.8 million in common stock shares from time to time in open market transactions at prevailing market prices or by other means in accordance with applicable regulations as part of a $20.0 million common stock repurchase program announced in* May 2021.No shares were repurchased during2025* or2024. Historically, stock repurchases have been funded from cash dividends paid to us from Mercantile Bank. Additional repurchases* may*be made in future periods under the authorized plan or a new plan, which would also likely be funded from cash dividends paid to us from our banks. The actual timing, number and value of shares repurchased will be determined by us in our discretion and will depend on a number of factors, including the stock price, capital position, financial performance, general market and economic conditions, alternative uses of capital and applicable legal requirements.

Our consolidated capital levels as of* December 31, 2025and2024* include $48.9 million and $48.3 million, respectively, of trust preferred securities. Under applicable Federal Reserve guidelines, the trust preferred securities constitute a restricted core capital element. The guidelines provide that the aggregate amount of restricted core capital elements that* maybe included in Tier1* capital mustnot exceed 25% of the sum of all core capital elements, including restricted core capital elements, net of goodwill less any associated deferred tax liability. Our ability to include the trust preferred securities in Tier1 capital in accordance with the guidelines isnot affected by the provision of the Dodd-Frank Act generally restricting such treatment, because (i) the trust preferred securities were issued before* May 19, 2010,and (ii) our total consolidated assets as of December 31, 2009were less than $15.0 billion. At December 31, 2025and2024*, all $48.9 million and $48.3 million, respectively, of the trust preferred securities were included as Tier1 capital of Mercantile.

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NOTE19 - REGULATORY MATTERS (Continued)

Our actual capital levels and minimum required levels at year-end2025 and2024 were:

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NOTE20 – MERCANTILE BANK CORPORATION (PARENT COMPANY ONLY)

CONDENSED FINANCIAL STATEMENTS

CONDENSED BALANCE SHEETS

CONDENSED STATEMENTS OF INCOME

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NOTE20 – MERCANTILE BANK CORPORATION (PARENT COMPANY ONLY)

CONDENSED FINANCIAL STATEMENTS (Continued)

CONDENSED STATEMENTS OF CASH FLOWS

December 31, 2025

NOTE21 – BUSINESS SEGMENT INFORMATION

Pursuant to Financial Accounting Standards Codification280, *Segment Reporting,*operating segments represent components of an enterprise for which separate financial information is available that is regularly evaluated by the chief operating decision makers in determining how to allocate resources and assessing performance.

Prior to our acquisition of Eastern Michigan Financial Corporation on* December 31, 2025,our chief operating decision makers, which include our Chief Executive Officer, Chief Financial Officer, and Chief Operating Officer, evaluated interest and noninterest income streams and credit losses from our various products and services, while expense activities, including interest expense and noninterest expense, were managed, and financial performance was evaluated, on a Company-wide basis. As a result, detailed profitability information for each interest and noninterest income stream wasnot* used by our chief operating decision makers to allocate resources or in assessing performance. Rather, our chief operating decision makers used consolidated net income to assess performance by comparing it to and monitoring against budgeted and prior-year results. This information was used to manage resources to drive business and net income growth, including investment in key strategic priorities, as well as determine our ability to return capital to shareholders.

Subsequent to our acquisition of Eastern Michigan Financial Corporation on* December 31, 2025,*our chief operating decision makers now evaluate interest and noninterest income streams, credit losses, expense activities, and financial performance through ourtwo wholly owned subsidiary banks, Mercantile Bank and Eastern Michigan Bank. Each of these operating segments offer similar products and services, but are managed separately due to different pricing, product demand, and consumer markets. Both segments derive interest and noninterest income through their banking products and services and investment securities. All of our income relates to our operations in the United States. Our chief operating decision makers use subsidiary level net income to assess performance by comparing it to and monitoring against budgeted and prior-year results. This information is used to manage resources to drive business and net income growth, including investment in key strategic priorities, as well as determine our ability to return capital to shareholders.

Segment net income represented net income on our Consolidated Statements of Income during and for the years ended* December 31, 2025,* 2024 and2023. Segment assets represented total assets and goodwill represented total goodwill on our Consolidated Balance Sheets as of* December 31, 2024.Goodwill, core deposit intangible, and total assets by segment as of December 31, 2025*were as follows:

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NOTE22 – SUBSEQUENT EVENTS

On* January 15, 2026,our Board of Directors declared a cash dividend on our common stock in the amount of $0.39 per share that will be paid on March 18, 2026,to shareholders of record as of March 6, 2026.*

EXHIBIT INDEX

• Management contract or compensatory plan.