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 future results could differ.  The allowance for credit losses and fair values of financial instruments are particularly subject to change.

Concentration of Credit Risk:  Loans are granted to, and deposits are obtained from, customers primarily in the western Michigan area as described above. Substantially all loans are secured by specific items of collateral, including residential real estate, commercial real estate, commercial assets and consumer assets. Commercial real estate loans are the largest concentration, comprising 44% of total loans at December 31, 2023. Commercial and industrial loans total 38%, while residential real estate and consumer loans make up the remaining 18%.  Other financial instruments, which potentially subject the Company to concentrations of credit risk, include deposit accounts in other financial institutions.

Cash Flow Reporting: Cash flows are reported net for customer loan and deposit transactions, interest-bearing time deposits with other financial institutions and short-term borrowings with maturities of 90 days or less.

Securities: Securities are classified as held to maturity ("HTM") and carried at amortized cost when management has the positive intent and ability to hold them to maturity. Securities available for sale ("AFS") consist of those securities which might be sold prior to maturity due to changes in interest rates, prepayment risks, yield and availability of alternative investments, liquidity needs or other factors. Securities classified as AFS are reported at their fair value and the related unrealized gain or loss is reported in other comprehensive income, net of tax.

Interest income includes amortization of purchase premium or discount. Premiums and discounts on securities are amortized on the level yield method without anticipating prepayments. Gains and losses on sales are based on the amortized cost of the security sold. Accrued interest receivable on securities totaled $3.4 million at December 31, 2023 and $3.4 million at  December 31, 2022.

Securities Available for Sale - For securities AFS in an unrealized loss position, management determines whether they intend to sell or if it is more likely than not that the Company 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 security's amortized cost basis is written down to fair value through income with an allowance for credit losses ("ACL") being established under CECL.  For securities AFS with unrealized losses not meeting these criteria, management evaluates whether any decline in fair value is due to credit loss factors.  In making this assessment, management considers any changes to the rating of the security by rating agencies 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 ACL is recorded for the credit loss, limited by the amount that the fair value is less than the amortized cost basis.  Changes in the ACL under ASC 326-30 are recorded as provisions for (or reversal of) credit loss expense.  Losses are charged against the allowance when the collectability of a debt security AFS is confirmed or when either of the criteria regarding intent or requirement to sell is met.  Any impairment that has not been recorded through an ACL is recognized in other comprehensive income, net of income taxes.  The Company has never experienced a loss on any debt securities AFS.  At December 31, 2023 and at adoption of CECL on January 1, 2023, there was no ACL related to debt securities AFS.  Accrued interest receivable on debt securities was excluded from the estimate of credit losses.

Securities Held to Maturity - Since the adoption of CECL, the Company measures credit losses on HTM securities on a collective basis by major security type with each type sharing similar risk characteristics, and considers historical credit loss information that is adjusted for current conditions and reasonable and supportable forecasts. The ACL on securities HTM is a contra asset valuation account that is deducted from the carrying amount of HTM securities to present the net amount expected to be collected.  HTM securities are charged off against the ACL when deemed uncollectible.  Adjustments to the ACL are reported in the Company's Consolidated Statements of Income in the provision for credit losses.  Accrued interest receivable on HTM securities is excluded from the estimate of credit losses.  With regard to US Treasury securities, these have an explicit government guarantee; therefore, no ACL is recorded for these securities.  With regard to obligations of states and political subdivisions and other HTM securities, management considers (1) issuer bond ratings, (2) historical loss rates for given bond ratings, (3) the financial condition of the issuer, and (4) whether issuers continue to make timely principal and interest payments under the contractual terms of the securities.  The Company has never experienced any loss on HTM securities.  At December 31, 2023 and at adoption of CECL on January 1, 2023, there was no ACL related to securities HTM.

For periods prior to January 1, 2023, management evaluated securities for other-than-temporary impairment ("OTTI") at least on a quarterly basis, and more frequently when economic or market conditions warranted such an evaluation.  Investment securities classified as available for sale or held-to-maturity were generally evaluated for OTTI under ASC Topic 320, Investments — Debt and Equity Instruments.  In determining OTTI, management considered many factors, including: (1) the length of time and the extent to which the fair value has been less than cost, (2) the financial condition and near-term prospects of the issuer, (3) whether the market decline was affected by macroeconomic conditions, and (4) whether the entity had the intent to sell the debt security or more likely than not would be required to sell the debt security before its anticipated recovery. The assessment of whether an other-than-temporary decline exists involved a high degree of subjectivity and judgment and was based on the information available to management at a point in time. Management determined that no OTTI charges were necessary during 2022.

Loans Held for Sale:  Mortgage loans originated and intended for sale in the secondary market are carried at fair value, as determined by outstanding commitments from investors.  As of December 31, 2023 and 2022, these loans had a net unrealized gain of $0 and $4,000, respectively, which are reflected in their carrying value.  Changes in fair value of loans held for sale are included in net gains on mortgage loans.  Loans are sold servicing released; therefore no mortgage servicing right assets are established.

Allowance for Credit Losses ("ACL") - Loans: Since the adoption of CECL, the allowance for credit losses (allowance) is a valuation account that is deducted from the loan portfolios' amortized cost basis to present the net amount expected to be collected on loans.  The allowance is increased by the provision for credit losses and recoveries, and decreased by charge-offs of loans. Management believes the allowance balance to be adequate based on known and inherent risks in the portfolio, past loan loss experience, information about specific borrower situations and estimated collateral values, current and forecasted economic conditions and other relevant factors. Allocations of the allowance may be made for specific loans, but the entire allowance is available for any loan that, in management’s judgment, should be charged-off. Loan losses are charged against the allowance when management believes the uncollectability of a loan balance is confirmed. Management continues its collection efforts on previously charged-off balances and applies recoveries as additions to the allowance.

The allowance is measured on a collective pool basis when similar risk characteristics exist.  Loans with similar risk characteristics are grouped into homogeneous classes, or pools, for allowance calculation.  Commercial loans are divided into eight classes based primarily on property type and risk characteristics.  They are further segmented based on commercial loan risk grade.  Retail loans are segmented into categories including residential mortgage, home equity, unsecured and other secured and then further segmented based on delinquency status.

The Company's loan portfolio classes as of December 31, 2023 were as follows:

Commercial Loans:

Commercial and Industrial - Risks to this category include industry concentration and limitations associated with monitoring the adequacy and condition of collateral which can include inventory, accounts receivable, and other non-real estate assets. Equipment and inventory obsolescence can also pose a risk. Declines in general economic conditions and other events can cause cash flows to fall to levels insufficient to service debt.

Residential developed - Risks to this category include industry concentration, valuation of residential properties, inventory of homes for sale in the market area, inadequate long-term financing arrangements and velocity of sales. Loans in this category are susceptible to weakening general economic conditions and increases in unemployment rates as well as market demand and supply of similar property. Declines in real estate values and lack of suitable alternative use for the properties are also risks for loans in this category.

Unsecured to residential developers - Risks to this category include industry concentration, valuation of residential properties, inventory of homes for sale in the market area and velocity of sales. Declines in general economic conditions and other events can cause cash flows to fall to levels insufficient to service debt.

Vacant and unimproved - Risks to this category include industry concentration, valuation of farm land, agricultural properties and residential properties as well as velocity of sales. Declines in general economic conditions and other events can cause cash flows to fall to levels insufficient to service debt. Declines in real estate values and lack of suitable alternative use for the properties are also risks for loans in this category.

Commercial development - Risks to this category include industry concentration, valuation of commercial properties, lease terms, occupancy/vacancy rates and velocity of sales. Declines in general economic conditions and other events can cause cash flows to fall to levels insufficient to service debt. Declines in real estate values and lack of suitable alternative use for the properties are also risks for loans in this category.

Residential improved - Risks to this category include industry concentration, valuation of residential properties, inventory of homes for sale in the market area and velocity of sales. Declines in general economic conditions and other events can cause cash flows to fall to levels insufficient to service debt. Declines in real estate values and lack of suitable alternative use for the properties are also risks for loans in this category.

Commercial improved - Risks to this category include industry concentration, valuation of commercial properties, lease terms, occupancy/vacancy rates, cost overruns, changes in market demand for property or services and velocity of sales. Declines in general economic conditions and other events can cause cash flows to fall to levels insufficient to service debt. Declines in real estate values and lack of suitable alternative use for the properties are also risks for loans in this category.

Manufacturing and industrial - Risks to this category include industry concentration, valuation of commercial properties, changes in market demand for products produced and velocity of sales. Declines in general economic conditions and other events can cause cash flows to fall to levels insufficient to service debt. Declines in real estate values and lack of suitable alternative use for the properties are also risks for loans in this category.

Consumer Loans:

Residential mortgage - Residential mortgage loans are susceptible to weakening general economic conditions and increases in unemployment rates and declining real estate values.

Unsecured - Unsecured loans are susceptible to weakening general economic conditions and increases in unemployment rates.

Home equity - Home equity loans are susceptible to weakening general economic conditions and increases in unemployment rates and declining real estate values.

Other secured - Other secured loans are susceptible to weakening general economic conditions and increases in unemployment rates, regulatory risks as well as the inability to monitor collateral consisting of personal property.

The remaining life methodology is used for all loan pools. This nondiscounted cash flow approach projects an estimated future amortized cost basis based on current loan balance and repayment terms. Given the bank's limited loss history over the past twelve years, a loss rate computed for a comparable sized peer group (banks with assets between $1-3 billion) is then applied to future loan balances at the instrument level based on the 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 period and reversion periods.

Reasonable and supportable economic forecasts have to be incorporated in determining expected losses. The forecast period represents the time frame from the current period end through the point in time that the Company can reasonably forecast. Ideally, the economic forecast period would cover the contractual terms of all loans; however, the ability to produce a forecast that is both reasonable and supportable becomes more difficult the longer the period is projected.

For periods beyond the forecast period, the loss rate reverts back to the baseline lifetime loss.  As of December 31, 2023, the Company used a one-year reasonable and supportable economic forecast period, with a six-month straight-line reversion period for all loan classes.  In determining the reasonable and supportable economic forecast period, the Company used a consensus economic forecast from a third-party provider that provided forecasts from twenty-five leading economists.  The Company considered the December 2023 report's consensus/mean estimates for gross domestic product and unemployment rates and selected a loss period for the reasonable and supportable forecast period that most closely matched that consensus.

A number of qualitative factors are considered including economic forecast uncertainty, credit quality trends, valuation trends, concentration risk, quality of loan review, changes in personnel, impact of rising interest rates, external factors and other considerations. During each reporting period, management also considers the need to adjust the baseline lifetime loss rates for factors that may cause expected losses to differ from those experienced in the historical loss periods.

The Company is also required to consider expected credit losses associated with loan commitments over the contractual period in which it is exposed to credit risk on the underlying commitments unless the obligation is unconditionally cancellable by the Company. Any allowance for off-balance sheet credit exposures is reported as an other liability on the Company's Consolidated Balance Sheet and is increased or decreased via provision for credit losses on the Company's 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 methodology, inputs and assumptions as the funded portion of loans at the segment level applied to the amount of commitments expected to be funded.

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 over the respective term of the loan using the level-yield method without anticipating prepayments. Accrued interest on loans totaled $5.3 million at December 31, 2023 and $4.0 million at December 31, 2022.

Accrued interest receivable for loans is included as a separate line item on the Company's Consolidated Balance Sheet. The Company elected not to measure an allowance for accrued interest receivable and instead elected to reverse accrued interest income on loans that are placed on nonaccrual status. The Company believes this policy results in the timely reversal of uncollectible interest.

Interest income on mortgage and commercial loans is discontinued at the time the loan is 90 days delinquent unless the loan is well-secured and in process of collection. Consumer loans are typically charged off no later than 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 or interest is considered doubtful. Nonaccrual loans and loans past due 90 days still on accrual include both smaller balance homogeneous loans that are collectively evaluated for impairment and individually classified impaired loans.

All interest accrued but not 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.

Foreclosed Assets:  Assets acquired through or instead of loan foreclosure, primarily other real estate owned, are initially recorded at fair value less estimated costs to sell when acquired, establishing a new cost basis.  If fair value declines, a valuation allowance is recorded through expense.  Costs after acquisition are expensed unless they add value to the property.

Bank-Owned Life Insurance (BOLI):   The Bank has purchased life insurance policies on certain officers. BOLI is recorded at its currently realizable cash surrender value.  Changes in cash surrender value are recorded in other income.

Loan Commitments and Related Financial Instruments:  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.

Revenue From Contracts With Customers:  The Company records revenue from contracts with customers in accordance with Accounting Standards Codification Topic 606, “Revenue from Contracts with Customers” (“Topic 606”).  Under Topic 606, the Company 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) it satisfies a performance obligation.  No revenue has been recognized in the current reporting period that results from performance obligations satisfied in previous periods.

The Company’s primary sources of revenue are derived from interest and dividends earned on loans, securities and other financial instruments that are not within the scope of Topic 606.  The Company has evaluated the nature of its 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 was not necessary.

The Company generally satisfies its 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 Topic 606 that significantly affects the determination of the amount and timing of revenue from contracts with customers.

Interest Income: The Company’s largest source of revenue is interest income which is primarily recognized on an accrual basis based on contractual terms written into loans and investment contracts.

Noninterest Revenue:  The Company derives the majority of its noninterest revenue from: (1) service charges for deposit related services, (2) gains related to mortgage loan sales, (3) trust fees and (4) debit and credit card interchange income.  Most of these services are transaction based and revenue is recognized as the related service is provided.

Income Taxes:  Income tax expense is the sum of the current year income tax due or refundable and the change in deferred tax assets and liabilities.  Deferred tax assets and liabilities are the expected future tax consequences of temporary differences between the carrying amounts and tax bases of assets and liabilities, computed using enacted tax rates.  The Company records a valuation allowance when management believes it is "more likely than not" that deferred tax assets will not be realized.

The Company recognizes a tax position as a benefit only if it is “more likely than not” that the tax position would be sustained in a tax examination, with a tax examination being presumed to occur.  The amount recognized is the largest amount of tax benefit that is greater than 50% likely of being realized on examination.  For tax positions not meeting the “more likely than not” test, no tax benefit is recorded.

The Company recognizes interest and/or penalties related to income tax matters in income tax expense.

Stock-Based Compensation:  Compensation cost for equity-based awards is measured on the grant date based upon the fair value of the award at that date, and is recognized over the requisite service period, net of forfeitures when they occur.  Fair value of restricted stock awards is based upon the quoted market price of the common stock on the date of grant.

Loss 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.

Dividend Restriction:  Banking regulations require maintaining certain capital levels and impose limitations on dividends paid by the Bank to the Company and by the Company to shareholders.

Segment Reporting:  The Company, through the branch network of the Bank, provides a broad range of financial services to individuals and companies in western Michigan.  These services include demand, time and savings deposits; lending; ATM and debit card processing; cash management; and trust and brokerage services.  While the Company’s management team monitors the revenue streams of the various Company products and services, operations are managed and financial performance is evaluated on a Company-wide basis.  Accordingly, all of the Company’s banking operations are considered by management to be aggregated in one operating segment – commercial banking.

Accounting Standards Updates:

Accounting Standards Codification (Topic 848), Reference Rate Reform, provides temporary optional expedients and exceptions to GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burdens of the expected market transition from LIBOR and other interbank offered rates to alternative reference rates. Entities can elect not to apply certain modification accounting requirements to contracts affected by reference rate reform, if certain criteria are met. Entities that make such elections would not have to remeasure contracts at the modification date or reassess a previous accounting determination.  Entities can elect various optional expedients that would allow them to continue applying hedge accounting for hedging relationships affected by reference rate reform, if certain criteria are met.  The Company adopted the LIBOR transition relief allowed under this standard in 2022.

ASU No. 2022-02 Financial Instruments - Credit Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures:  This ASU eliminates the accounting guidance for troubled debt restructurings (TDRs) by creditors in Subtopic 310-40, Receivables - Troubled Debt Restructurings by Creditors, while adding disclosures for certain loan restructurings by creditors when a borrower is experiencing financial difficulty.  This guidance requires an entity to determine whether the modification results in a new loan or a continuation of an existing loan.  Additionally, the ASU requires disclosure of current period gross writeoffs by year of origination for financing receivables.  The ASU also requires disclosure of current period gross writeoffs by year of origination for financing receivables and disclosure of certain modifications of receivables made to borrowers experiencing financial difficulty.  This ASU is effective for the Company for fiscal years beginning after December 15, 2022. Adoption of this ASU on January 1, 2023 did not have a material impact on the Company’s financial results and the additional required disclosures for gross writeoffs have been included in the footnotes to the consolidated financial statements.

ASU No. 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures:  This ASU enhances disclosures about significant segment expenses.  The key amendments include: (1) require that a public entity disclose on an annual an interim basis, significant segment expenses that are regularly provided to the chief operating decision maker (CODM) and included within each reported measure of segment profit or loss, (2) require that a public entity disclose, on an annual and interim basis, an amount for other segment items by reportable segment and a description of its composition, (3) require that a public entity provide all annual disclosures about a reportable segment's profit or loss currently required by GAAP in interim periods as well, (4) clarify that if CODM uses more than one measure of a segment's profit or loss in assessing segment performance and deciding how to allocate resources, an entity may report one or more of those additional measures of segment profit, (5) require that a public entity disclose the title and position of the CODM and an explanation of how the CODM uses the reported measure of segment profit or loss in assessing segment performance and deciding how to allocate resources and (6) require that a public entity that has a single reportable segment provide all the disclosures required by the amendments in the ASU and all existing segment disclosures.  This ASU is effective for public entities for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024.  As the Company has one reportable segment, the requirements of this standard for such entities will apply beginning with the Company's annual report ending December 31, 2024.  The Company does not expect adoption of the ASU to have a material effect on the Company's consolidated financial statements.

ASU No. 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures:  This ASU requires that public business entities on an annual basis (1) disclose specific categories in the rate reconciliation and (2) provide additional information for reconciling items that meet a quantitative threshold.  The ASU requires all entities disclose on an annual basis (1) the amount of income taxes paid, disaggregated by federal, state and foreign taxes and (2) the amount of income taxes paid disaggregated by individual jurisdictions in which income taxes paid is equal or greater than 5 percent of total income taxes paid.  The ASU also requires that all entities disclose (1) income (loss) from continuing operations before income tax expense (or benefit) disaggregated between domestic or foreign and (2) income tax expense (or benefit) from continuing operations disaggregated by federal (national), state and foreign.  This ASU is effective for public business entities for annual periods beginning after December 15, 2024.  The Company does not expect adoption of the ASU to have a material effect on the Company's consolidated financial statements.