BASIS OF PRESENTATION AND CONSOLIDATION: The consolidated financial statements include the accounts of Isabella Bank Corporation, a financial services holding company, and its wholly owned subsidiary, Isabella Bank. All intercompany balances and accounts have been eliminated in consolidation. References to “the Corporation”, “Isabella”, “we”, “our”, “us”, and similar terms refer to the consolidated entity consisting of Isabella Bank Corporation and its subsidiary. References to Isabella Bank or “the Bank” refers to Isabella Bank Corporation’s subsidiary, Isabella Bank.

NATURE OF OPERATIONS: Isabella Bank Corporation is a financial services holding company offering a wide array of financial products and services in several mid-Michigan counties. Our banking subsidiary, Isabella Bank, offers banking services throughout 31 locations, offering lending and deposit services, trust and investment services, and various insurance related products.

OPERATING SEGMENTS: Segment information is prepared on the same basis that our CEO, who is our Chief Operating Decision Maker (“CODM”), manages our segments, evaluates financial results, and makes key operating decisions. While the CODM monitors the revenue streams of our various products and services, operations are managed, and financial performance is evaluated on a corporate-wide basis. Operating segments are aggregated into one as operating results for all segments are similar. Accordingly, all of the banking related operations are considered by management to be aggregated in one reportable operating segment.

The segment is also distinguished by the level of information provided to the CODM, who uses such information to review performance of various components of the business, which are then aggregated if operating performance, products and services, and geographical regions are similar. The CODM will evaluate the financial performance of our business components by evaluating revenue streams, significant expenses, and budget to actual results in assessing our reportable segment and in the determination of allocating resources. Further, the CODM uses revenue streams to evaluate product pricing and significant expenses to assess performance and evaluate return on assets.

Consolidated net income is used to benchmark results against our competitors. Benchmarking and the monitoring of budget to actual results are used in assessment performance and in establishing compensation. Revenue from banking operations consists primarily of loan and investment interest, deposit related fees, and wealth fees. Interest expense, provision for credit losses, compensation, and occupancy and equipment costs provide the significant expenses in our banking operations. All operations are domestic.

USE OF ESTIMATES: In preparing consolidated financial statements in conformity with accounting principles generally accepted in the United States of America, we make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the consolidated balance sheet and reported amounts of revenues and expenses during the reporting year. Actual results could differ from those estimates.

SUBSEQUENT EVENTS: We evaluated subsequent events after December 31, 2024 through the date our consolidated financial statements were issued for potential recognition and disclosure. No subsequent events require financial statement recognition or disclosure between December 31, 2024 and the date our consolidated financial statements were issued.

FAIR VALUE MEASUREMENTS: Fair value refers to the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants in the market in which the reporting entity transacts such sales or transfers based on the assumptions market participants would use when pricing an asset or liability. Assumptions are developed based on prioritizing information within a fair value hierarchy that gives the highest priority to quoted prices in active markets and the lowest priority to unobservable data, such as the reporting entity’s own data. We may choose to measure eligible items at fair value at specified election dates.

market. In cases where the market for a financial asset or liability is not active, we include appropriate risk adjustments that market participants would make for nonperformance and liquidity risks when developing fair value measurements. Fair value measurements for assets and liabilities for which limited or no observable market data exists are accordingly based primarily upon estimates, are often calculated based on the economic and competitive environment, the characteristics of the asset or liability and other factors. Therefore, the results cannot be determined with precision and may not be realized in an actual sale or immediate settlement of the asset or liability. Additionally, there may be inherent weaknesses in any calculation technique, and changes in the underlying assumptions used, including discount rates and estimates of future cash flows, could significantly affect the results of current or future values.

We utilize fair value measurements to record fair value adjustments to certain assets and liabilities and to determine fair value disclosures. Investment securities AFS are recorded at fair value on a recurring basis. Additionally, from time to time, we may be required to record other assets and liabilities at fair value on a nonrecurring basis, such as mortgage loans AFS, collateral dependent loans, foreclosed assets, OMSR, goodwill, and certain other assets and liabilities. These nonrecurring fair value adjustments typically involve the application of lower of cost or market accounting or write downs of individual assets.

Under fair value measurement and disclosure authoritative guidance, we group assets and liabilities measured at fair value into three levels, based on the markets in which the assets and liabilities are traded, and the reliability of the assumptions used to determine fair value, based on the prioritization of inputs in the valuation techniques. These levels are:


Level 1:			Valuation is based upon quoted prices for identical instruments traded in active markets.
Level 2:			Valuation is based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model based valuation techniques for which all significant assumptions are observable in the market.
Level 3:			Valuation is generated from model based techniques that use at least one significant assumption not observable in the market. These unobservable assumptions reflect estimates of assumptions that market participants would use in pricing the asset or liability.

The asset’s or liability’s fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Valuation techniques maximize the use of observable inputs and minimize the use of unobservable inputs. Transfers between measurement levels are recognized at the end of reporting periods.

SIGNIFICANT GROUP CONCENTRATIONS OF CREDIT RISK: Most of our activities are conducted with customers located within the central Michigan area. A significant amount of our outstanding loans are secured by commercial and residential real estate. Other than these types of loans, there is no significant concentration to any other industry or any one customer.

CASH AND CASH EQUIVALENTS: For purposes of the consolidated statements of cash flows, cash and cash equivalents include cash and balances due from banks, federal funds sold, and other deposit accounts. Generally, federal funds sold are for a one day period. We maintain deposit accounts in various financial institutions which generally exceed federally insured limits or are not insured. We do not believe we are exposed to any significant interest, credit or other financial risk as a result of these deposits.

AFS SECURITIES: Purchases of investment securities are generally classified as AFS. However, we may elect to classify securities as either held to maturity or trading. Securities classified as AFS debt securities are recorded at fair value, with unrealized gains and losses, net of the effect of deferred income taxes, excluded from earnings and reported in other comprehensive income (loss). Included in AFS securities are auction rate money market preferred securities. These investments, for federal income tax purposes, have no federal income tax impact given the nature of the investments. Auction rate money market preferred securities are recorded at fair value, with unrealized gains and losses excluded from earnings and reported in other comprehensive income (loss). Purchase premiums and discounts are recognized in interest income using the interest method over the term of the securities. Realized gains and losses on the sale of AFS securities are determined using the specific identification method.

ACL - AFS SECURITIES: AFS securities are reviewed quarterly for possible credit impairment. In determining whether a credit-related impairment exists for debt securities, we assess whether: (a) we do not have the intent to sell the security; and (b) it is more likely than not we will not have to sell the security before recovery of its cost basis. If either of these conditions are met, any previously recognized allowances are charged-off and the security's amortized cost is written down to fair value

In order to determine the amount of the credit loss for a debt security, we calculate the recovery value by performing a discounted cash flow analysis based on the current cash flows and future cash flows we expect to recover. If the present value of cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit losses is recorded for the credit loss, limited by the amount that the fair value is less than the amortized cost basis. The amount of the impairment related to other risk factors is recognized as a component of other comprehensive income. Adjustments to the allowance are reported in the income statement as a provision for credit losses.

We made an accounting policy election to exclude accrued interest receivable on AFS securities from the estimate of credit losses. Accrued interest receivable on AFS securities was $1,701 and $2,247 at December 31, 2024, and 2023, which is included in other assets. AFS securities are charged-off against the allowance or, in the absence of any allowance, written down through income when deemed uncollectible by management, or when criteria regarding intent or requirement to sell is met.

LOANS: Loans held for investment are reported at amortized cost. Amortized cost is the principal balance outstanding net of the unamortized balance of deferred fees and costs and any unamortized premium or discount on loan purchases or acquired. Interest income on loans is accrued over the term of the loan based on the principal amount outstanding. Loan origination fees and certain direct loan origination costs are capitalized and recognized as a component of interest income over the term of the loan using the appropriate yield methods.

NONPERFORMING LOANS: The accrual of interest on agricultural, commercial and mortgage loans is discontinued at the time the loan is 90 days or more past due unless the credit is well secured and in the process of collection. Consumer loans are typically charged-off no later than 180 days past due. Past due status is based on contractual terms of the loan. In all cases, loans are placed in nonaccrual status or charged-off at an earlier date if collection of principal or interest is considered doubtful. For loans that are placed on nonaccrual status or charged-off, all interest accrued in the current calendar year, but not collected, is reversed against interest income while interest accrued in prior calendar years, but not collected is charged against the ACL. Interest income on loans in nonaccrual status is not recognized until qualifying for return to accrual status. Loans are returned to accrual status when all principal and interest amounts contractually due are brought current and future payments are reasonably assured. For loans not classified as nonaccrual, interest income continues to be accrued over the term of the loan based on the principal amount outstanding.

ACL - LOANS: The ACL is established through a provision for credit losses charged to earnings. Loan losses are charged against the allowance when we believe the uncollectability of the loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance. We made an accounting policy election to exclude accrued interest receivable on loans from the estimate of credit losses. Accrued interest receivable on loans was $6,384 and $5,920 at December 31, 2024, and 2023, which is included in other assets.

We evaluate the ACL on a regular basis. Our periodic review of the collectability of loans considers historical experience, the nature and volume of the loan portfolio, adverse situations that may affect the borrower’s ability to repay, estimated value of any underlying collateral, prevailing economic conditions, and reasonable and supportable forecasts. This evaluation is inherently subjective as it requires estimates that are susceptible to significant revision as more information becomes available.

The ACL consists of a general component and loans individually analyzed. The general component covers loans not specifically analyzed and is based on historical loss experience, current conditions, and reasonable and supportable forecasts. The general component also includes uncertainties that we believe could affect our estimate of probable losses based on qualitative factors.

Loans in nonaccrual status are individually analyzed on a loan-by-loan basis. Loans evaluated individually are not included in the general, or pooled, component of the ACL. For collateralized loans, the loan's specific allowance is measured by the fair value of the collateral approach. The specific reserve is based on the fair value of the collateral, less costs to sell if foreclosure is probable, and an allowance is established when the collateral value is lower than the carrying value of the loan. When the discounted cash flow method is used to measure the loan's specific allowance, the effective interest rate is used to discount expected cash flows to incorporate expected prepayments. An allowance is established when the discounted cash flows are lower than the carrying value of the loan. For large groups of smaller-balance, homogeneous loans, we may collectively evaluate these loans for measurement of an allowance.

LOAN MODIFICATIONS: A loan modification includes terms outside of normal lending practices to a borrower experiencing financial difficulty. Loans are considered to have been modified when, due to a borrower’s financial difficulties, certain concessions are made to the borrower that would not otherwise consider. Modifications may include interest rate reductions, principal or interest forgiveness, forbearance, and other actions intended to minimize economic loss and to avoid

LOANS HELD FOR SALE: Mortgage loans held for sale on the secondary market are carried at the lower of cost or fair value as determined by aggregating outstanding commitments from investors or current investor yield requirements. Net unrealized losses, if any, would be recognized as a component of other noninterest expenses.

ACCRUED INTEREST: Accrued interest receivable balances are presented within other assets on the consolidated balance sheet. Accrued interest is excluded from the measurement of the allowance for credit losses, including investments and loans. Generally, accrued interest is reversed when a loan is placed in nonaccrual status or charged off. Current year accrued interest is reversed through interest income while accrued interest from prior years is charged off through the ACL.

TRANSFERS OF FINANCIAL ASSETS: Transfers of financial assets, including mortgage loans and participation loans, are accounted for as sales when control over the assets has been surrendered. Control over transferred assets is determined to be surrendered when 1) the assets have been legally isolated from us, 2) the transferee obtains the right (free of conditions that constrain it from taking advantage of the right) to pledge or exchange the transferred assets, and 3) we do not maintain effective control over the transferred assets through an agreement to repurchase them before their maturity. Other than servicing, we have no substantive continuing involvement related to these loans.

CAPITALIZED MORTGAGE SERVICING RIGHTS: Servicing assets are recognized as separate assets when rights are acquired through purchase or through sale of financial assets. We have no purchased servicing rights. For sales of mortgage loans, a portion of the cost of originating the loan is allocated to the servicing right based on relative fair value. Fair value is based on market prices for comparable mortgage servicing contracts, when available, or alternatively, is based on a valuation model that calculates the present value of estimated future net servicing income. The valuation model incorporates assumptions that market participants would use in estimating future net servicing income, such as the cost to service, the discount rate, the custodial earnings rate, an inflation rate, ancillary income, prepayment speeds and default rates and losses.

Servicing assets are evaluated for impairment based upon the fair value of the rights as compared to amortized cost. Impairment is determined by stratifying rights into tranches based on predominant risk characteristics, such as interest rate, loan type, and investor type. Impairment is recognized through a valuation allowance for an individual tranche, to the extent that fair value is less than the capitalized amount for the tranche. If we later determine that all or a portion of the impairment no longer exists for a particular tranche, a reduction of the valuation allowance may be recorded as an increase to income. Capitalized servicing rights are reported in other assets and are amortized into noninterest income in proportion to, and over the period of, the estimated future net servicing income of the underlying financial assets. The unpaid principal balance of mortgages serviced for others was $231,143 and $248,756 with capitalized servicing rights of $2,185 and $2,422 at December 31, 2024 and 2023, respectively.

Servicing fee income is recorded for fees earned for servicing loans for others. The fees are based on a contractual percentage of the outstanding principal or a fixed amount per loan and are recorded as income when earned. We recorded servicing fee revenue of $588, $630, and $669 related to residential mortgage loans serviced for others during 2024, 2023, and 2022, respectively, which is included in service charges and fees.

FORECLOSED ASSETS: Assets acquired through, or in lieu of, loan foreclosure are held for sale and are initially recorded at the lower of our carrying amount or fair value less estimated selling costs at the date of transfer, establishing a new cost basis. Any write downs based on the asset’s fair value at the date of acquisition are charged to the ACL. After foreclosure, property held for sale is carried at the lower of the new cost basis or fair value less costs to sell. Impairment losses on property to be held and used are measured at the amount by which the carrying amount of property exceeds its fair value. Costs relating to holding these assets are expensed as incurred. We periodically perform valuations and any subsequent write downs are recorded as a charge to operations, if necessary, to reduce the carrying value of a property to the lower of our carrying amount or fair value less costs to sell. Foreclosed assets of $544 and $406 as of December 31, 2024 and 2023, respectively, are included in other assets.

PREMISES AND EQUIPMENT: Land is carried at cost. Buildings and equipment are carried at cost, less accumulated depreciation which is computed principally by the straight-line method based upon the estimated useful lives of the related assets, which range from 3 to 40 years. Major improvements are capitalized and appropriately amortized based upon the useful lives of the related assets or the expected terms of the leases, if shorter, using the straight-line method. Maintenance, repairs and minor alterations are charged to current operations as expenditures occur. We annually review these assets to determine whether carrying values have been impaired.

EQUITY SECURITIES WITHOUT READILY DETERMINABLE FAIR VALUES: We hold equity securities without readily determinable fair values which include our holdings of FHLB stock and FRB stock. Equity securities without readily determinable fair values, with the exception of FHLB stock, are included in other assets. Equity securities without readily determinable fair values consist of the following holdings as of December 31:


	2024		2023
FHLB Stock	$	12,762	$	12,762
FRB Stock	2,400		2,400
Other	686		686
Total	$	15,848	$	15,848

Under the RSP, compensation expense for nonvested stock awards is based on the fair value of the award on the measurement date. The fair value of nonvested stock awards is based on the date of the grant and is recognized over the requisite service period. The impact of forfeitures of share-based payment awards on compensation expense is recognized as forfeitures occur.

BANK OWNED LIFE INSURANCE: We have purchased life insurance policies on key members of management, partially for the purpose of funding certain post-retirement benefits. In the event of death of one of these individuals, we would receive a specified cash payment equal to the face value of the policy. Such policies are recorded at their cash surrender value, or the amount that can be realized on the balance sheet date. Increases in cash surrender value in excess of single premiums paid are reported as earnings on BOLI policies.

Of the purchased life insurance policies, we hold post retirement benefits with a present value estimated to be $2,687 and $2,515 as of December 31, 2024 and 2023, respectively, which is included in other liabilities. The expenses associated with these policies totaled $172, $173, and $61 for 2024, 2023, and 2022, respectively, which are included in compensation and benefits expense and other noninterest expenses.

ACQUISITION INTANGIBLES AND GOODWILL: We previously acquired branch facilities and related deposits in business combinations accounted for as a purchase. The acquisitions included amounts related to the valuation of customer deposit relationships (core deposit intangibles). Core deposit intangibles arising from acquisitions are included in goodwill and other intangible assets are being amortized over their estimated lives and evaluated for potential impairment on at least an annual basis. Goodwill, which represents the excess of the purchase price over identifiable assets, is not amortized but is evaluated for impairment on at least an annual basis. Acquisition intangibles and goodwill are qualitatively evaluated to determine if it is more likely than not that the carrying balance is impaired. On at least an annual basis we perform a cash flow, trading multiples, and acquisition multiples valuation to determine if the carrying balance is impaired and to what extent goodwill is impaired. This valuation method requires a significant degree of our judgment. In the event the projected undiscounted net operating cash flows for these intangible assets are less than the carrying value, the asset is recorded at fair value as determined by the valuation model.

OFF BALANCE SHEET CREDIT RELATED FINANCIAL INSTRUMENTS: In the ordinary course of business, we have entered into commitments to extend credit, including commitments under credit card arrangements, commercial lines of credit, home equity lines of credit, commercial letters of credit, and standby letters of credit. Such financial instruments are recorded only when funded. In connection with these commitments, we established an allowance for credit losses related to off-balance-sheet credit exposures. The allowance, recorded in a liability account, is calculated in accordance with ASC 326 and represents expected credit losses over the contractual period for which we are exposed to credit risk resulting from a contractual obligation to extend credit. The estimate of expected credit losses considers both the likelihood that funding will occur and the amount expected to be funded over the estimated remaining life of the commitment. The likelihood and expected amount of

funding are based on historical utilization rates. No allowance is recognized if we have the unconditional right to cancel the obligation. The allowance is reported as a component of other liabilities. Adjustments to the allowance are reported in our income statement as a component of provision for credit losses.

REVENUE RECOGNITION: Our revenue is comprised primarily of interest income, service charges and fees, gains on the sale of loans and AFS securities, earnings on corporate owned life insurance policies, and other noninterest income. Other noninterest income is typically service and performance driven in nature and comprised primarily of investment and trust advisory fees. We recognize revenue, excluding interest income and other income specifically scoped out, in accordance with ASC 606, Revenue From Contracts with Customers. Revenue is recognized when our performance obligation has been satisfied according to our contractual obligation.

WEALTH MANAGEMENT: Wealth management assets held in a fiduciary or agent capacity are not included in our consolidated balance sheets because the ownership is held by customers. Trust and investment management fees are primarily comprised of fees earned from investment management, trust administration, tax return preparation, and financial planning.

FEDERAL INCOME TAXES: Deferred income tax assets and liabilities are determined using the liability (or balance sheet) method. Under this method, the net deferred tax assets or liabilities are determined based on the tax effects of the temporary differences between the book and tax basis on the various balance sheet assets and liabilities and gives current recognition to changes in tax rates and laws. Valuation allowances are established, where necessary, to reduce deferred tax assets to the amount expected to be realized. Income tax expense is the tax payable or refundable for the year plus or minus the change during the year in deferred tax assets and liabilities.

We analyze our filing positions in the jurisdictions where we are required to file income tax returns, as well as all open tax years in these jurisdictions. We also treat interest and penalties attributable to income taxes, to the extent they arise, as a component of our noninterest expenses.

EARNINGS PER SHARE: Basic earnings per common share represents income available to common shareholders divided by the weighted average number of common shares outstanding during the period. Diluted earnings per common share includes additional common shares that would have been outstanding if dilutive potential common shares had been issued.

DEFINED BENEFIT PENSION PLAN: We maintain a noncontributory defined benefit pension plan, which was curtailed effective March 1, 2007. The service cost component of the defined benefit pension plan is included in compensation and benefits and is funded consistent with the requirements of federal laws and regulations. All other costs related to the defined benefit pension plan are included in other noninterest expenses. The current benefit obligation is included in other liabilities. Inherent in the determination of defined benefit pension costs are assumptions concerning future events that will affect the amount and timing of required benefit payments under the plan. These assumptions include demographic assumptions such as mortality, a discount rate used to determine the current benefit obligation and a long-term expected rate of return on plan assets. Net periodic benefit cost includes the interest cost based on the assumed discount rate, an expected return on plan assets based on an actuarially derived market-related value of assets, and amortization of unrecognized net actuarial gains or losses. Actuarial gains and losses result from experience different from that assumed and from changes in assumptions (excluding asset gains and losses not yet reflected in market-related value). Amortization of actuarial gains and losses is included as a component of net periodic defined benefit pension cost.

ASU No. 2023-07, issued in November 2023, requires public business entities with a single reportable segment to provide the disclosures required by this standard and the existing segment disclosures in Topic 280 on an interim and annual basis. The ASU updates reportable segment disclosure requirements, primarily through requiring enhanced disclosures about significant segment expenses and information used to assess segment performance. The new authoritative guidance is effective for annual

In December 2023, ASU No. 2023-09 was issued to enhance the transparency and decision usefulness of income tax disclosures. The existing disclosure is being enhanced to provide information to help investors, lenders, creditors and all other allocators of capital asses how an entity's operations and related tax risks and tax planning and operational opportunities affect its tax rate and prospects for future cash flows. The new authoritative guidance is effective for annual periods beginning after December 15, 2024 and will not have a significant impact on our operations or financial statement disclosures.

In November 2024, ASU No. 2024-03 was issued to improve the disclosures about a public business entity’s expenses and address requests from investors for more detailed information about the types of expenses (including purchases of inventory, employee compensation, depreciation, amortization, and depletion) in commonly presented expense captions (such as cost of sales, selling general and administrative expense, and research and development). The new authoritative guidance is effective for annual periods beginning after December 15, 2026, and interim periods within annual reporting periods beginning after December 15, 2027, as clarified in ASU No. 2025-01 issued in January 2025. The new authoritative guidance under ASU No. 2024-03 is not expected to have a significant impact on our operations or financial statement disclosures.