SOUTHSIDE BANCSHARES INC

1. SUMMARY OF SIGNIFICANT ACCOUNTING AND REPORTING POLICIES

Organization. Southside Bancshares, Inc., incorporated in Texas in 1982, is a bank holding company for Southside Bank, a Texas state bank headquartered in Tyler, Texas that was formed in 1960. We operate through 53 branches,12 of which are located in grocery stores. We consider our primary market areas to be East Texas, Southeast Texas, as well as the greater Dallas-Fort Worth, Austin and Houston, Texas areas. We are a community-focused financial institution that offers a full range of financial services to individuals, businesses, municipal entities and nonprofit organizations in the communities that we serve. These services include consumer and commercial loans, deposit accounts, wealth management and trust services, brokerage services and safe deposit services.

Basis of Presentation and Consolidation. The consolidated financial statements are prepared in conformity with U.S. GAAP and include the accounts of Southside Bancshares, Inc., and its wholly-owned subsidiary, Southside Bank, and the nonbank subsidiaries. All significant intercompany accounts and transactions are eliminated in consolidation.

We determine if we have a controlling financial interest in an entity by first evaluating whether the entity is a voting interest entity or a VIE under GAAP. Voting interest entities are entities in which the total equity investment at risk is sufficient to enable the entity to finance itself independently and provides the equity holders with the obligation to absorb losses, the right to receive residual returns and the right to make decisions about the entity’s activities. We consolidate voting interest entities in which we have all, or at least a majority of, the voting interest. As defined in applicable accounting standards, VIEs are entities that lack one or more of the characteristics of a voting interest entity. A controlling financial interest in a VIE is present when an enterprise has both the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and an obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The enterprise with a controlling financial interest, known as the primary beneficiary, consolidates the VIE.

Accounting Changes and Reclassifications. Certain prior period amounts may be reclassified to conform to current period presentation.

Use of Estimates. In preparing consolidated financial statements in conformity with GAAP, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities as of the date of the balance sheet and reported amounts of revenues and expenses during the reporting period. These estimates are subjective in nature and involve matters of judgment. Actual results could differ from these estimates. Material estimates that are particularly susceptible to significant change in the near term relate to the determination of the allowance for credit losses. The status of contingencies are particularly subject to change.

Segment Information. Operating segments are components of a business about which separate financial information is available and that are evaluated regularly by the chief operating decision maker in deciding how to allocate resources and assess performance. Our chief operating decision maker uses consolidated results to make operating and strategic decisions. Therefore, we have determined that our business is conducted inone reportable segment. Further information on our segment reporting is included in “Note 19 – Segment Reporting.”

Cash Equivalents. Cash equivalents, for purposes of reporting cash flow, include cash, amounts due from banks and federal funds sold that have an initial maturity of less than 90 days. We maintain deposits with other institutions in amounts that exceed federal deposit insurance coverage. Management regularly evaluates the credit risk associated with the counterparties to these transactions and believes that we are not exposed to any significant credit risks on cash and cash equivalents.

Basic and Diluted Earnings per Common Share. Basic earnings per common share is calculated based on the two-class method in accordance with ASC Topic 260, “Earnings Per Share.” ASC 260 provides that unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating securities and shall be included in the calculation of earnings per share pursuant to the two-class method. We have determined that our director’s deferred RSUs are participating securities.

Under the two-class method, basic earnings per common share is calculated by dividing net income available to common shareholders by the weighted-average number of common shares outstanding during the period, excluding outstanding participating securities. Diluted earnings per common share is calculated using the weighted-average number of shares determined for the basic earnings per common share calculation plus the dilutive effect of stock awards using the treasury stock method. A reconciliation of the weighted-average shares used in calculating basic earnings per common share and the weighted average common shares used in calculating diluted earnings per common share for the reported periods is provided in “Note 2 – Earnings Per Share.”

Comprehensive Income. Comprehensive income includes all changes in shareholders’ equity during a period, except those resulting from transactions with shareholders. Besides net income, other components of comprehensive income include the after tax effect of changes in the fair value of AFS securities, changes in the net unrealized loss on securities transferred to/from HTM, changes in the accumulated gain or loss on effective cash flow hedging instruments and changes in the funded status of defined benefit retirement plans. Comprehensive income is reported in the accompanying consolidated statements of comprehensive income and in “Note 3 – Accumulated Other Comprehensive Income (Loss).”

Loans. Loans that management has the intent and ability to hold for the foreseeable future or until maturity or pay-off are reported at amortized cost. Amortized cost consists of the outstanding principal balance adjusted for any charge-offs and any unamortized origination fees and unamortized premiums or discounts on purchased loans. Loan origination fees, net of certain direct origination costs, are deferred and recognized in interest income over the life of the loan. A loan is considered impaired, based on current information and events, if it is probable that we will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Substantially all of our individually evaluated loans are collateral-dependent, and as such, are measured for expected credit losses based on the fair value of the collateral, less estimated cost to sell.

Loans Held For Sale. Loans originated and intended for sale in the secondary market are carried at the lower of aggregate cost or fair value, as determined by aggregate outstanding commitments from investors or current investor yield requirements. Net unrealized losses are recognized through a valuation allowance by charges to income. Gains or losses on sales of mortgage loans are recognized based on the difference between the selling price and the carrying value of the related mortgage loans sold.

From time to time, certain commercial real estate loans are held for sale which are carried at the lower of cost or fair value.

Loan Fees. We treat loan fees, net of direct costs, as an adjustment to the yield of the related loan over its term.

Allowance for Credit Losses – Loans. In accordance with ASC 326, the allowance for credit losses on loans is estimated and recognized upon origination of the loan based on expected credit losses. The CECL model uses historical experience and current conditions for homogeneous pools of loans, and reasonable and supportable forecasts about future events. The impact of varying economic conditions and portfolio stress factors are a component of the credit loss models applied to each portfolio. Reserve factors are specific to the loan segments that share similar risk characteristics based on the probability of default assumptions and loss given default assumptions, over the contractual term. The forecasted periods gradually mean-revert the economic inputs to their long-run historical trends. Management evaluates the economic data points used in the Moody’s forecasting scenarios on a quarterly basis to determine the most appropriate impact to the various portfolio characteristics based on management’s view and applies weighting to various forecasting scenarios as deemed appropriate based on known and expected economic activities. Management also considers and may apply relevant qualitative factors, not previously considered, to determine the appropriate allowance level. The use of the CECL model includes significant judgment by management and may differ from those of our peers due to different historical loss patterns, economic forecasts, and the length of time of the reasonable and supportable forecast period and reversion period.

We utilize Moody’s Analytics economic forecast scenarios and assign probability weighting to those scenarios which best reflect management’s views on the economic forecast. The probability weighting and scenarios utilized for the estimate of the allowance were generally reflective of continued economic and repricing uncertainty, as based on known and knowable information as of December 31, 2025.

When determining the appropriate allowance for credit losses on our loan portfolio, our commercial construction and real estate loans, commercial loans and municipal loans utilize the probability of default/loss given default discounted cash flow approach. Reserves on these loans are based upon risk factors including the loan type and structure, collateral type, leverage ratio, refinancing risk and origination quality, among others. Our consumer construction real estate loans, 1-4 family residential loans and our loans to individuals use a loss rate based upon risk factors including loan types, origination year and credit scores.

Loans evaluated collectively in a pool are monitored to ensure they continue to exhibit similar risk characteristics with other loans in the pool. If a loan does not share similar risk characteristics with other loans, expected credit losses for that loan are evaluated individually.

When assessing for credit losses from period to period, the change may be indicative of changes in the estimates of timing or the amount of future cash flows, based on the probability of economic forecast scenarios applied, as well as the passage of time. We have elected to report the entire change in present value as provision for credit losses.

When using the discounted cash flow method to determine the allowance for credit losses, management does not adjust the effective interest rate used to discount expected cash flows to incorporate expected prepayments, but rather applies separate prepayment factors.

Accrued Interest. Accrued interest for our loans and debt securities, included in interest receivable on our consolidated balance sheets, is excluded from the estimate of allowance for credit losses.

Nonaccrual Assets and Loan Charge-offs. Nonaccrual assets include financial assets 90 days or more delinquent and full collection of both principal and interest is not expected. Financial instruments that are not delinquent or that are delinquent less than 90 days may be placed on nonaccrual status if it is probable that we will not receive contractual principal or interest. When an asset is categorized as nonaccrual, the accrual of interest is discontinued and any accrued balance is reversed for financial statement purposes. Payments received on nonaccrual assets are applied to the outstanding principal balance. Payments of contractual interest are recognized as income only to the extent that full recovery of the principal balance is reasonably certain. Assets are returned to accrual status when all payments contractually due are brought current and future payments are reasonably assured.

Industry and our own experience indicate that a portion of our loans will become delinquent and a portion of our loans will require partial or full charge-off. Regardless of the underwriting criteria utilized, losses may occur as a result of various factors beyond our control, including, among other things, changes in market conditions affecting the value of properties used as collateral for loans and problems affecting the credit worthiness of the borrower and the ability of the borrower to make payments on the loan. We charge-off loans when deemed uncollectible. Our policy is to charge-off or partially charge-off a retail credit after it is 120 days past due. Charge-offs on commercial credits are determined on a case-by-case basis when a credit loss has been determined.

Restructured Loans. A loan is considered restructured if the borrower is experiencing financial difficulties and the loan has been modified. Modifications may include interest rate reductions or below market interest rates, restructuring amortization schedules and other actions intended to minimize potential losses. We may provide a combination of modifications which may include an extension of the amortization period, interest rate reduction and/or converting the loan to interest-only for a limited period of time. In most instances, interest will continue to be charged on principal balances outstanding during the extended term.

OREO and Foreclosed Assets. OREO includes real estate acquired in full or partial settlement of loan obligations. OREO is initially carried at the fair value of the collateral net of estimated selling costs. Prior to foreclosure, the recorded amount of the loan is written down, if necessary, to the appraised fair value of the real estate to be acquired, less selling costs, by charging the allowance for loan losses. Any subsequent reduction in fair value net of estimated selling costs is charged to noninterest expense. Costs of maintaining and operating foreclosed properties are expensed as incurred and included in other expense in our income statement. Expenditures to complete or improve foreclosed properties are capitalized only if expected to be recovered; otherwise, they are expensed.

Other foreclosed assets are held for sale and are initially recorded at fair value less estimated selling costs at the date of foreclosure, by charging the allowance for loan losses. Subsequent to foreclosure, valuations are periodically performed by management and the assets are carried at the lower of carrying amount or fair value less costs to sell. Foreclosed assets are included in other assets in the accompanying consolidated balance sheets. Expenses from operations and changes in the valuation allowance are included in noninterest expense.

Securities. AFS. Debt securities that will be held for indefinite periods of time, including securities that may be sold in response to changes in market interest or prepayment rates, needs for liquidity or changes in the availability of and the yield on alternative investments are classified as AFS. These assets are carried at fair value with unrealized gains and losses, not related to credit losses, reported as a separate component of AOCI, net of tax. Fair value is determined using quoted market prices as of the close of business on the balance sheet date. If quoted market prices are not available, fair values are based on quoted market prices for similar securities or estimates from independent pricing services. AFS securities hedged with qualifying derivatives are carried at fair value with the change in the fair value on both the hedged instrument and the securities recorded in interest income in the consolidated statements of income.

Gains and losses on the sale of securities are recorded in the month of the trade date and are determined using the specific identification method.

HTM. Debt securities that management has the positive intent and ability to hold until maturity are classified as HTM and are carried at their amortized cost which includes the remaining unpaid principal balance, net of unamortized premiums or unaccreted discounts. Our HTM securities are presented on the consolidated balance sheets net of allowance for credit losses, if any. As of December 31, 2025, there was a $25,000 allowance for credit losses on our HTM securities portfolio.

Premiums and Discounts. Premiums and discounts on debt securities are generally amortized over the contractual life of the security, except for MBS where prepayments are anticipated and for callable debt securities whose premiums are amortized to the earliest call date in accordance with ASC 310. The amortization of purchased premium or discount is included in interest income on our consolidated statements of income. Premiums on debt securities are amortized to the earliest call date.

Allowance for Credit Losses – AFS Securities. In accordance with ASC 326, for AFS debt securities in an unrealized loss position where management (i) has the intent to sell or (ii) where it will more-likely-than-not be required to sell the security before the recovery of its amortized cost basis, we recognize the loss in earnings. For those AFS debt securities in an unrealized loss position that do not meet either of these criteria, management assesses whether the decline in fair value has resulted from credit losses or other factors. Management assesses the financial condition and near-term prospects of the issuer, industry and/or geographic conditions, credit ratings as well as other indicators at the individual security level. If a credit loss is determined to exist, the present value of discounted cash flows expected to be collected from the security are compared to the amortized cost basis of the security. If the present value of discounted cash flows expected to be collected is less than the amortized cost basis, a credit loss exists and an allowance for credit loss is recorded, limited by the amount that the fair value is less than the amortized cost. Any impairment that is not recorded through an allowance for credit losses is recognized in other comprehensive income. Any future changes in the allowance for credit losses is recorded as provision for (reversal of) credit losses.

Allowance for Credit Losses – HTM Securities. In accordance with ASC 326, expected credit losses on HTM securities are measured on a collective basis by major security type, when similar risk characteristics exist. Risk characteristics for segmenting HTM debt securities include issuer, maturity, coupon rate, yield, payment frequency, source of repayment, bond payment structure, and embedded options. Upon assignment of the risk characteristics to the major security types, management may further evaluate the qualitative factors associated with these securities to determine the expectation of credit losses, if any.

The major security types within our HTM portfolio include residential and commercial MBS, state and political subdivisions and corporate securities.

Our state and political subdivisions include highly-rated municipal securities with a long history of no credit losses. Our investment policy prohibits bond purchases with a rating less than BAA and limits our entity concentration. We utilize term structures and due to no prior loss exposure on our state and political subdivision securities, we apply third-party average data to model our securities to represent the portion of the asset that would be lost if the issuer were to default. These third-party estimates of recoveries and defaults, adjusted for constant probability over the securities expected life, are used to evaluate the expected loss of the securities. Due to the limited number and the nature of the HTM state and political subdivisions we hold, we do not model these securities as a pool, but on the specific identification method in conjunction with the application of our third-party fair value measurement.

Our residential and commercial MBS are issued and/or guaranteed by U.S. government agencies or GSEs and are collateralized by pools of single- or multi-family mortgages. Our MBS are highly rated securities with a long history of no credit losses which are either explicitly or implicitly backed by the U.S. government agencies, which guarantee the payment of principal and interest to investors. Management has collectively evaluated the characteristics of these securities and has assumed an expectation of zero credit loss.

Our corporate bonds and other investment securities consist of primarily investment grade bonds and private placement bonds with a long history of no credit losses.

We reevaluate the characteristics of our major security types at every reporting period and reassess the considerations to continue to support our expectation of credit loss.

Equity Investments. Equity investments with readily determinable fair values are stated at fair value with the unrealized gains and losses reported in other noninterest income in the consolidated statements of income. Equity investments without readily determinable fair values are recorded at cost less impairment, if any.

Securities with Limited Marketability. Securities with limited marketability, such as stock in the FHLB, are carried at cost, which is a reasonable estimate of the fair value of those assets and are assessed for other-than-temporary impairment.

Premises and Equipment. Land is carried at cost. Bank premises and equipment are stated at cost, net of accumulated depreciation. Depreciation is computed on a straight line basis over the estimated useful lives of the related assets. Useful lives are estimated to be 15 to 40 years for premises and 3 to 10 years for equipment. Leasehold improvements are generally depreciated over the lesser of the term of the respective leases or the estimated useful lives of the improvements. Maintenance and repairs are charged to expense as incurred while major improvements and replacements are capitalized.

Leases. We evaluate our contracts at inception to determine if an arrangement is or contains a lease. Operating leases are included in operating lease ROU assets and operating lease liabilities in our consolidated balance sheets. Our operating leases relate primarily to bank branches and office space. The Company has no finance leases. Short-term leases, leases with an initial term of 12 months or less and do not contain a purchase option that is likely to be exercised, are not recorded on the balance sheet.

ROU assets represent our right to use an underlying asset for the lease term, and lease liabilities represent our obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of the future lease payments over the lease term. Our leases do not provide an implicit rate, so we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The incremental borrowing rate is reevaluated upon lease modification. The operating lease ROU asset also includes any initial direct costs and prepaid lease payments made less any lease incentives. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option.

BOLI. The Company has purchased life insurance policies on certain key executives and officers. BOLI is recorded at the amount that can be realized under the insurance contract at the balance sheet date, which is the cash surrender value adjusted for other charges or other amounts due that are probable at settlement. Changes in the net cash surrender value of the policies, as well as insurance proceeds received are reflected in noninterest income on the consolidated statements of income and are not subject to income taxes.

Goodwill and Other Intangibles. Other intangible assets consist primarily of core deposits and trust relationship intangibles. Intangible assets with definite useful lives are amortized on an accelerated basis over their estimated life. Goodwill and intangible assets that have indefinite useful lives are subject to at least an annual impairment test and more frequently if a triggering event occurs. If any such impairment is determined, a write-down is recorded.

We have selected October 1 of each year as the measurement date on which we will complete our annual goodwill impairment assessment. We may first assess qualitative factors to determine whether it is necessary to perform the quantitative analysis. We performed a qualitative assessment to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. The qualitative factors considered include, but are not limited to, macroeconomic and State of Texas economic conditions, industry and market conditions and trends, the Company’s financial performance, market capitalization, stock price, control premium analysis and any Company-specific events relevant to the assessment. If the assessment of qualitative factors indicates that it is not more likely than not that an impairment exists, no further testing is required; otherwise an impairment test is performed. For the year ended December 31, 2025, the Company’s goodwill impairment evaluation, based on its qualitative assessment, indicated there was no impairment. As a result, we didnot record any goodwill impairment for the years ended December 31, 2025 or 2024, and we hadno cumulative goodwill impairment.

At December 31, 2025, core deposit intangible and trust relationship intangible was $232,000 and $780,000, respectively. For the years ended December 31, 2025, 2024 and 2023, amortization expense related to our core deposit intangible and trust relationship intangible was $742,000, $1.2 million and $1.7 million, respectively.

Repurchase Agreements. We sell certain securities under agreements to repurchase. The agreements are treated as collateralized financing transactions and the obligations to repurchase securities sold are reflected as a liability in the accompanying consolidated balance sheets. The dollar amount of the securities underlying the agreements remains in the asset account. We determine the type of debt securities to pledge which may include investment securities and U.S. agency MBS.

Derivative Financial Instruments and Hedging Activities. Derivative financial instruments are carried on the consolidated balance sheets as other assets or other liabilities, as applicable, at estimated fair value, and the net change in each of these financial statement line items in the accompanying consolidated statements of cash flows. The accounting for changes in the fair value (i.e., gains or losses) of a derivative financial instrument is determined by whether it has been designated and qualifies as part of a hedging relationship and, further, by the type of hedging relationship. We present derivative financial instruments at fair value in the consolidated balance sheets on a net basis when a right of offset exists, based on transactions with a single counterparty and any cash collateral paid to and/or received from that counterparty for derivative contracts that are subject to legally enforceable master netting arrangements.

For derivative instruments that are designated and qualify as cash flow hedges (i.e., hedging the exposure to variability in expected future cash flows that is attributable to a particular risk), the effective portion of the gain or loss on the derivative instrument is reported as a component of AOCI and reclassified to interest expense in the same periods that the hedged cash flows impact earnings. Gains and losses on derivative instruments designated as fair value hedges, as well as the change in the fair value on the hedged item, are recorded in interest income in the consolidated statements of income. Gains and losses due to changes in the fair value of the interest rate swap agreements offset changes in the fair value of the hedged portion of the hedged item. For derivative instruments not designated as hedging instruments, the gain or loss is recognized in current earnings during the period of change. Cash flows from the settlement of derivatives, including those designated in hedge accounting relationships, are reflected in the Consolidated Statements of Cash Flows in the same categories as the cash flows from the items being hedged.

For derivatives designated as hedging instruments at inception, statistical regression analysis is used at inception and for each reporting period thereafter to assess whether the derivative used has been and is expected to be highly effective in offsetting changes in the fair value or cash flows of the hedged item. All components of each derivative instrument’s gain or loss are included in the assessment of hedge effectiveness. Net hedge ineffectiveness is recorded in interest income on the consolidated statements of income.

Terminated Derivative Financial Instruments. In accordance with ASC Topic 815, if a hedging item is terminated prior to maturity for a cash settlement, the existing gain or loss within AOCI will continue to be reclassified into earnings during the period or periods in which the hedged forecasted transaction affects earnings unless it is probable that the forecasted transaction will not occur by the end of the originally specified time period. These transactions are reevaluated on a monthly basis to determine if the hedged forecasted transactions are still probable of occurring. If at a subsequent evaluation, it is determined that the transactions are probable of not occurring, any related gains or losses recorded in AOCI are immediately recognized in earnings.

Further information on our derivative instruments and hedging activities is included in “Note 11 – Derivative Financial Instruments and Hedging Activities.”

Allowance for Credit Losses – Off-Balance-Sheet Credit Exposures. Our off-balance-sheet credit exposures include contractual commitments to extend credit and standby letters of credit. For these credit exposures we evaluate the expected credit losses using usage given defaults and credit conversion factors depending on the type of commitment and based upon historical usage rates. These assumptions are reevaluated on an annual basis and adjusted if necessary. In accordance with Topic 326, credit losses are not recognized for those credit exposures that are unconditionally cancellable by the Company.

The allowance for credit losses for these off-balance-sheet credit exposures is included in other liabilities on our consolidated balance sheets and is adjusted with a corresponding adjustment to provision for credit losses on our consolidated statements of income.

Revenue Recognition. Our revenue consists of net interest income on financial assets and financial liabilities and noninterest income. The classifications of our revenue are presented in the consolidated statements of income.

In accordance with ASC Topic 606, revenue is recognized when obligations under the terms of a contract with our customer are satisfied; generally this occurs with the transfer of control of goods or services. We recognize revenue equal to the amounts for which we have a right to invoice, revenue is measured as the amount of consideration we expect to receive in exchange for the transfer of those goods or services. We generally expense sales commissions when incurred because the amortization period is within one year or less. These costs are recorded within salaries and employee benefits on the consolidated statements of income.

The following summarizes our revenue recognition policies as they relate to revenue from contracts with customers:

•Deposit services. Service charges on deposit accounts include fees for banking services provided, overdrafts and non-sufficient funds. Revenue is generally recognized in accordance with published deposit account agreements for retail accounts or contractual agreements for commercial accounts. Our deposit services also include our ATM and debit card interchange revenue that is presented net of the associated costs. Interchange revenue is generated by our deposit customers’ usage and volume of activity. Interchange rates are not controlled by the Company, which effectively acts as processor that collects and remits payments associated with customer debit card transactions.

•Trust income. Trust income includes fees and commissions from investment management, administrative and advisory services primarily for individuals, and to a lesser extent, partnerships and corporations. Revenue is recognized on an accrual basis at the time the services are performed and when we have a right to invoice and are based on either the market value of the assets managed or the services provided.

•Brokerage services. Brokerage services income includes fees and commissions charged when we arrange for another party to transfer brokerage services to a customer. The fees and commissions under this agent relationship are based upon stated fee schedules based upon the type of transaction, volume and value of the services provided.

•Other noninterest income. Other noninterest income includes among other things, merchant services income. Merchant services revenue is derived from third-party vendors that process credit card transactions on behalf of our merchant customers. Merchant services revenue is primarily comprised of residual fee income based on the referred merchant’s processing volumes and/or margin.

Income Taxes. We file a consolidated federal income tax return. Income tax expense represents the taxes expected to be paid or returned for current year taxes adjusted for the change in deferred tax assets and liabilities. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of changes in tax rates is recognized in income in the period the change occurs. Uncertain tax positions arise when it is more likely than not that the tax position taken will be sustained upon examination by the appropriate tax authority. Any income tax benefit as well as penalties and interest related to income tax expense are recorded as a component of income tax expense. Unrecognized tax benefits were not material as of December 31, 2025 or 2024.

Fair Value 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. In cases where quoted market prices are not available, fair values are based on estimates using present value or other estimation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows.

Retirement Plan. Defined benefit pension obligations and the annual pension costs are determined by independent actuaries and through the use of a number of assumptions that are reviewed by management. These assumptions include a discount rate used to determine the current benefit obligation and a long-term expected rate of return on plan assets. Net periodic defined benefit pension expense includes interest cost based on the assumed discount rate, an expected return on plan assets and amortization of net actuarial gains or losses. Actuarial gains and losses result from experience different from that assumed and from changes in assumptions. Amortization of actuarial gains and losses is included as a component of net periodic defined benefit pension cost. All other of these cost components are recorded in other noninterest expense.

During 2024, we adopted a liability-driven investment strategy for the Retirement Plan. The liability-driven investment strategy focuses on matching the cash flow generated by assets to the cash flow of the retirement benefit obligation, therefore minimizing risks that could affect returns, such as those associated with interest rate fluctuations and market volatility. As a result of minimizing gains and losses that would significantly impact the amortization of the existing actuarial loss, we changed the amortization method of actuarial loss from average life expectancy to average future service. As a result of this amortization method change, our net periodic benefit cost of the Retirement Plan increased to $2.0 million in 2025 compared to net periodic benefit income of $659,000 in 2024.

The retirement plan obligations, related assets and net periodic benefit costs of our defined benefit pension plan are presented in “Note 10 – Employee Benefits.”

Share-Based Awards. Compensation expense for NQSOs and RSUs is based on the fair value on the date of the grant and is recorded over the grant’s vesting period. Compensation expense for PSUs is based on the fair value on the date of the grant and is recorded over the service period of the award based upon the probable number of units expected to vest. Share-based compensation for employees is recognized as compensation cost in the consolidated statements of income. Share-based compensation for non-employee directors is recognized as other noninterest expense in the consolidated statements of income.

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.

Wealth Management and Trust Assets. Our wealth management and trust assets, other than cash on deposit at Southside Bank, are not included in the accompanying financial statements, because they are not our assets.

Accounting Pronouncements.

In December 2023, the FASB issued ASU 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures. ASU 2023-09 enhances the transparency of decision-usefulness of income tax disclosures, particularly in the rate reconciliation table and disclosures about income taxes paid. ASU 2023-09 is effective for fiscal years beginning after December 15, 2024. Early adoption is permitted. The guidance should be applied prospectively with an option to apply it retrospectively for each period presented. We adopted ASU 2023-09 on January 1, 2025. ASU 2023-09 did not have a material impact on our consolidated financial statements.

In November 2024, the FASB issued ASU 2024-03, “Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40).” ASU 2024-03 requires disaggregated disclosure of income statement expenses within the footnotes to the financial statements for any relevant expense caption presented on the face of the income statement within continuing operations into the following required natural expense categories, as applicable: (1) purchases of inventory, (2) employee compensation, (3) depreciation, (4) intangible asset amortization, and (5) depreciation, depletion and amortization recognized as part of oil- and gas-producing activities or other types of depletion services. ASU 2024-03 is effective for fiscal years beginning after December 15, 2026, and interim periods within fiscal years beginning after December 15, 2027. Early adoption is permitted. The guidance should be applied prospectively with an option to apply it retrospectively for each period presented. We are currently evaluating the potential impact of ASU 2024-03 on our consolidated financial statements.

In November 2025, the FASB issued ASU 2025-08, “Financial Instruments - Credit Losses (Topic 326): Purchased Loans.” ASU 2025-08 expands the population of acquired financial assets subject to the gross-up approach to include purchased seasoned loans. The gross-up approach requires recognition of an allowance for expected credit loss for the estimate of credit losses at the acquisition date. The allowance for expected credit loss is recorded with an offsetting gross-up adjustment to the purchase price of the acquired financial asset. ASU 2025-08 is effective for fiscal years and interim periods within those fiscal years, beginning after December 15, 2026. Early adoption is permitted. The guidance should be applied prospectively to loans acquired on or after the adoption date. We are currently evaluating the potential impact of ASU 2025-08 and do not expect it to have a material impact on our consolidated financials.

In November 2025, the FASB issued ASU 2025-09, “Derivatives and Hedging (Topic 815): Hedge Accounting Improvements.” ASU 2025-09 makes certain targeted improvements to simplify the application of the hedge accounting guidance and to address several incremental hedge accounting issues arising from the global reference rate reform initiative. These improvements include expanding the hedged risks permitted to be aggregated in a group of individual forecasted transactions in a cash flow hedge and clarifying the circumstances under which a group of individual forecasted transactions can be considered to have a similar risk exposure. ASU 2025-09 is effective for fiscal years and interim periods within those fiscal years, beginning after December 15, 2026. Early adoption is permitted. The guidance should be applied prospectively for all hedging relationships. We are currently evaluating the potential impact of ASU 2025-09 and do not expect it to have a material impact on our consolidated financial statements.

In December 2025, the FASB issued ASU 2025-11, “Interim Reporting (Topic 270): Narrow-Scope Improvements.” ASU 2025-11 clarifies the applicability of Topic 270 and the form and content of interim financial statements. In addition, ASU 2015-11 requires entities to disclose material events occurring since the last annual reporting period. ASU 2025-11 is effective for interim periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. The guidance can be applied prospectively or retrospectively for each period presented. We are currently evaluating the potential impact of ASU 2025-11 and do not expect it to have a material impact on our consolidated financials.

2. EARNINGS PER SHARE

Earnings per share on a basic and diluted basis are calculated as follows (in thousands, except per share amounts):

For the year ended December 31, 2025, there were approximately 460,000 anti-dilutive shares. For the years ended December 31, 2024 and 2023, there were approximately 525,000 and 570,000 anti-dilutive shares, respectively.

3. ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)

The changes in accumulated other comprehensive income (loss) by component are as follows for the years presented (in thousands):

The reclassification adjustments out of accumulated other comprehensive income (loss) included in net income are presented below (in thousands):

(1)Included in interest income on the consolidated statements of income.

(2)Listed as net gain (loss) on sale of securities AFS on the consolidated statements of income.

(3)Included in interest expense for FHLB borrowings, other borrowings and deposits on the consolidated statements of income.

(4)These AOCI components are included in the computation of net periodic pension cost (income) presented in “Note 10 – Employee Benefits.”

4. SECURITIES

Debt securities

The amortized cost, gross unrealized gains and losses and estimated fair value of investment and mortgage-backed AFS and HTM securities, net of allowance for credit losses, as of December 31, 2025 and 2024 are reflected in the tables below (in thousands):

(1)All MBS issued and/or guaranteed by U.S. government agencies or U.S. GSEs.

From time to time, we transfer securities from AFS to HTM due to overall balance sheet strategies and our intent and ability to hold these securities until maturity. We didnot transfer any securities from AFS to HTM during the years ended December 31, 2025 or 2024. The remaining net unamortized, unrealized loss on the transferred securities included in AOCI in the accompanying balance sheets totaled $96.6 million ($76.3 million, net of tax) at December 31, 2025 and $105.1 million ($83.0 million, net of tax) at December 31, 2024. Any net unrealized gain or loss on the transferred securities included in AOCI at the time of transfer will be amortized over the remaining life of the underlying security as an adjustment to the yield on those securities. Securities transferred with losses included in AOCI continue to be included in management’s assessment for impairment for each individual security.

Investment securities and MBS with carrying values of $1.94 billion and $2.18 billion were pledged as of December 31, 2025 and December 31, 2024, respectively, to collateralize borrowings from the FRDW, repurchase agreements and public fund deposits, for potential liquidity needs or other purposes as required by law. At December 31, 2025 and December 31, 2024, the amount of excess collateral at the FRDW was $241.8 million and $431.7 million, respectively.

The following tables present the fair value and unrealized losses on AFS, if applicable, for which an allowance for credit losses has not been recorded, as well as HTM investment securities and MBS, if applicable, as of December 31, 2025 and 2024, segregated by major security type and length of time in a continuous loss position (in thousands):

For those AFS debt securities in an unrealized loss position (i) where management has the intent to sell or (ii) where it will more-likely-than-not be required to sell the security before the recovery of its amortized cost basis, we recognize the loss in earnings. For those AFS debt securities in an unrealized loss position that do not meet either of these criteria, management assesses whether the decline in fair value has resulted from credit-related factors, using both qualitative and quantitative criteria. Determining the allowance under the credit loss method requires the use of a discounted cash flow method to assess the credit losses. Any credit-related impairment will be recognized in allowance for credit losses on the balance sheet with a corresponding adjustment to earnings. Noncredit-related temporary impairment, the portion of the impairment relating to factors other than credit (such as changes in market interest rates), is recognized in other comprehensive income, net of tax.

As of December 31, 2025 and 2024, we didnot have an allowance for credit losses on our AFS securities, based on our consideration of the qualitative factors associated with each security type in our AFS portfolio. The unrealized losses on our investment and MBS are due to changes in interest rates and spreads and other market conditions. We had 161 and 421 AFS debt securities in an unrealized loss position at December 31, 2025 and 2024, respectively. Our state and political subdivisions are highly rated municipal securities with a long history of no credit losses. Our AFS MBS are highly rated securities which are either explicitly or implicitly backed by the U.S. Government through its agencies and which are highly rated by major ratings agencies and also have a long history of no credit losses. Our corporate bonds and other investment securities consist of primarily investment grade bonds.

We assess the likelihood of default and the potential amount of default when assessing our HTM securities for credit losses. We utilize term structures and, due to no prior loss exposure on our state and political subdivision securities or our corporate securities, we currently apply a third-party average loss given default rate to model these securities. We elected to use the collective evaluation method to model our HTM securities, which aligns with our third-party fair value measurement process. The model determined an expected credit loss over the life of the HTM securities of $25,000, and such amount was recognized as credit loss for the year ended December 31, 2025. For the year ended December 31, 2024, no provision for credit loss was recognized. Management evaluated the remote expectation of loss on the HTM portfolio, along with the qualitative factors associated with these securities, as well as the credit loss estimate of the model and concluded that an allowance for credit loss of $25,000 was sufficient as of December 31, 2025, due to the securities being highly rated municipals with a long history of no credit losses.

The accrued interest receivable on our debt securities is excluded from the credit loss estimate and is included in interest receivable on our consolidated balance sheets. As of December 31, 2025, accrued interest receivable on AFS and HTM debt securities totaled $9.4 million and $12.7 million, respectively. As of December 31, 2024, accrued interest receivable on AFS and HTM debt securities totaled $13.6 million and $12.9 million, respectively. No HTM debt securities were past-due or onno naccrual status as of December 31, 2025 or 2024.

The following table reflects interest income recognized on securities for the periods presented (in thousands):

There was a $32.3 million net realized loss as a result of sales from the AFS securities portfolio for the year ended December 31, 2025, which consisted of $33.1 million in realized losses and $2.0 million in realized gains, as well as a net loss of $1.2 million on the unwind of fair value MBS and municipal securities hedges in the AFS securities portfolio. There was a $2.5 million net realized loss as a result of sales from the AFS securities portfolio for the year ended December 31, 2024, which consisted of $6.1 million in realized losses and $88,000 in realized gains, offset by a net gain of $3.5 million on the unwinding of fair value hedges on municipal securities in the AFS securities portfolio. There wereno sales from the HTM portfolio during the year ended December 31, 2025, 2024 or 2023. We calculate realized gains and losses on sales of securities under the specific identification method.

Expected maturities on our securities may differ from contractual maturities because issuers may have the right to call or prepay obligations. MBS are presented in total by category since MBS are typically issued with stated principal amounts and are backed by pools of mortgages that have loans with varying maturities. The characteristics of the underlying pool of mortgages, such as fixed-rate or adjustable-rate, as well as prepayment risk, are passed on to the security holder. The term of a mortgage- backed pass-through security thus approximates the term of the underlying mortgages and can vary significantly due to prepayments.

The amortized cost and estimated fair value of AFS and HTM securities at December 31, 2025, are presented below by contractual maturity (in thousands):

Equity Investments

Equity investments on our consolidated balance sheets include CRA funds with a readily determinable fair value as well as equity investments without readily determinable fair values. At December 31, 2025 and 2024, we had equity investments recorded in our consolidated balance sheets of $9.6 million and $9.5 million, respectively.

Any realized and unrealized gains and losses on equity investments are reported in income. Equity investments without readily determinable fair values are recorded at cost, less impairment, if any. For the year ended December 31, 2025, there wasno gain or loss on the sale of equity securities.

The following is a summary of unrealized and realized gains and losses on equity investments recognized in other noninterest income in the consolidated statements of income during the periods presented (in thousands):

FHLB Stock

Our FHLB stock, which has limited marketability, is carried at cost, less impairment, if any. Based upon our quarterly evaluation by management at December 31, 2025, our FHLB stock wasnot impaired.

5. LOANS AND ALLOWANCE FOR LOAN LOSSES

Loans in the accompanying consolidated balance sheets are classified as follows (in thousands):

Loans to Affiliated Parties

In the normal course of business, we make loans to certain of our executive officers and directors and their related interests. As of December 31, 2025 and 2024, these loans totaled $9.8 million and $12.1 million, respectively. These loans represented 1.2% and 1.5% of shareholders’ equity as of December 31, 2025 and 2024, respectively.

Construction Real Estate Loans

Our construction loans are collateralized by property located primarily in or near the market areas we serve. Some of our construction loans will be owner occupied upon completion. Construction loans for non-owner occupied projects are financed, but these typically have cash flows from leases with tenants, secondary sources of repayment, and in some cases, additional collateral. Our construction loans have both adjustable and fixed interest rates during the construction period. Construction loans to individuals are typically priced and made with the intention of granting the permanent loan on the completed property. Commercial construction loans typically have adjustable interest rates and are subject to underwriting standards similar to that of the commercial real estate loan portfolio. Owner occupied 1-4 family residential construction loans are subject to the underwriting standards of the permanent loan.

1-4 Family Residential Real Estate Loans

Residential loan originations are generated by our mortgage loan officers, in-house origination staff, marketing efforts, present customers, walk-in customers and referrals from real estate agents and builders. We focus our lending efforts primarily on the origination of loans secured by first mortgages on owner occupied 1-4 family residences. Substantially all of our 1-4 family residential originations are secured by properties located in or near our market areas.

Our 1-4 family residential loans generally have maturities ranging from 15 to 30 years. These loans are typically fully amortizing with monthly payments sufficient to repay the total amount of the loan. Our 1-4 family residential loans are made at both fixed and adjustable interest rates.

Underwriting for 1-4 family residential loans includes debt-to-income analysis, credit history analysis, appraised value and down payment considerations. Changes in the market value of real estate can affect the potential losses in the residential portfolio.

Commercial Real Estate Loans

Commercial real estate loans as of December 31, 2025 consisted of $1.94 billion of owner and non-owner occupied real estate, $742.7 million of loans secured by multi-family properties and $32.7 million of loans secured by farmland. Commercial real estate loans primarily include loans collateralized by retail, commercial office buildings, multi-family residential buildings, medical facilities and offices, senior living, assisted living and skilled nursing facilities, warehouse facilities, hotels and churches. In determining whether to originate commercial real estate loans, we generally consider such factors as the financial condition of the borrower and the debt service coverage of the property. Commercial real estate loans are made at both fixed and adjustable interest rates for terms generally up to 20 years.

Commercial Loans

Our commercial loans are diversified loan types including short-term working capital loans for inventory and accounts receivable and short- and medium-term loans for equipment or other business capital expansion. In our commercial loan underwriting, we assess the creditworthiness, ability to repay and the value and liquidity of the collateral being offered. Terms of commercial loans are generally commensurate with the useful life of the collateral offered.

Municipal Loans

We make loans to municipalities and school districts primarily throughout the state of Texas, with a small percentage originating outside of the state. The majority of the loans to municipalities and school districts have tax or revenue pledges and in some cases are additionally supported by collateral. Municipal loans made without a direct pledge of taxes or revenues are usually made based on some type of collateral that represents an essential service. These loans allow us to earn a higher yield than we could if we purchased municipal securities for similar durations.

Loans to Individuals

Substantially all originations of our loans to individuals are made to consumers in our market areas. The majority of loans to individuals are collateralized by titled equipment, which are primarily automobiles. Loan terms vary according to the type and value of collateral, length of contract and creditworthiness of the borrower. The underwriting standards we employ for consumer loans include an application and a determination of the applicant’s payment history on other debts, with the greatest weight being given to payment history with us and an assessment of the borrower’s ability to meet existing obligations and payments on the proposed loan. Although creditworthiness of the applicant is a primary consideration, the underwriting process also includes a comparison of the value of the collateral, if any, in relation to the proposed loan amount. Most of our loans to individuals are collateralized, which management believes assists in limiting our exposure.

Credit Quality Indicators

We categorize loans into risk categories on an ongoing basis based on relevant information about the ability of borrowers to service their debt such as: current financial information, historical payment experience, credit documentation, public information and current economic trends, among other factors. We use the following definitions for risk ratings:

•Pass (Rating 1 – 4) – This rating is assigned to all satisfactory loans. This category, by definition, consists of acceptable credit. Credit and collateral exceptions should not be present, although their presence would not necessarily prohibit a loan from being rated Pass, if deficiencies are in the process of correction. These loans are not included in the Watch List.

•Pass Watch (Rating 5) – These loans require some degree of special treatment, but not due to credit quality. This category does not include loans specially mentioned or adversely classified; however, particular attention is warranted to characteristics such as:

▪A lack of, or abnormally extended payment program;

▪A heavy degree of concentration of collateral without sufficient margin;

▪A vulnerability to competition through lesser or extensive financial leverage; and

▪A dependence on a single or few customers or sources of supply and materials without suitable substitutes or alternatives.

•Special Mention (Rating 6) – A Special Mention loan has potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the loan or in our credit position at some future date. Special Mention loans are not adversely classified and do not expose us to sufficient risk to warrant adverse classification.

•Substandard (Rating 7) – Substandard loans are inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. Loans so classified must have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. They are characterized by the distinct possibility that the Bank will sustain some loss if the deficiencies are not corrected.

•Doubtful (Rating 8) – Loans classified as Doubtful have all the weaknesses inherent in those classified Substandard with the added characteristic that the weaknesses make collection or liquidation, in full, on the basis of currently known facts, conditions and values, highly questionable and improbable.

The following tables set forth the amortized cost basis by class of financing receivable and credit quality indicator for the periods presented (in thousands):

(1)Includes $1.2 million in charged off demand deposit overdrafts reported as 2025 originations.

(1) Includes $1.2 million in charged off demand deposit overdrafts reported as 2024 originations.

Watch List loans reported as 2025 originations as of December 31, 2025 and Watch List loans reported as 2024 originations as of December 31, 2024 were, for the majority, first originated in various years prior to 2025 and 2024, respectively, but were renewed in the respective year.

The following tables present the aging of the amortized cost basis in past due loans by class of loans (in thousands):

The following table sets forth the amortized cost basis of nonperforming assets for the periods presented (in thousands):

(1)Includes$2.0 million and$63,000 of restructured loans as of December 31, 2025 and December 31, 2024, respectively.

The increase in restructured loans was due to the extension of maturity on a $27.5 million commercial real estate loan in the first quarter of 2025. We reversed $83,000 and $72,000 of interest income on nonaccrual loans during the years ended December 31, 2025 and 2024, respectively. We had $2.7 million and $650,000 of loans on nonaccrual for which there was no related allowance for credit losses as of December 31, 2025 and 2024, respectively.

Collateral-dependent loans are loans that we expect the repayment to be provided substantially through the operation or sale of the collateral of the loan and for which we have determined that the borrower is experiencing financial difficulty. In such cases, expected credit losses are based on the fair value of the collateral at the measurement date, adjusted for selling costs. As of December 31, 2025 and 2024, we had $38.4 million and $6.9 million, respectively, of collateral-dependent loans, secured mainly by real estate and equipment. There have been no significant changes to the collateral that secures the collateral-dependent assets. Foreclosed assets include OREO and repossessed assets. For 1-4 family residential real estate properties, a loan is recognized as a foreclosed property once legal title to the real estate property has been received upon completion of foreclosure or the borrower has conveyed all interest in the residential property through a deed in lieu of foreclosure. There wereno loans secured by 1-4 family residential properties for which formal foreclosure proceedings were in process as of December 31, 2025. There were$40,000 in loans secured by 1-4 family residential properties for which formal foreclosure proceedings were in process as of December 31, 2024.

Restructured Loans

A loan is considered restructured if the borrower is experiencing financial difficulties and the loan has been modified. Modifications may include interest rate reductions, restructuring amortization schedules, extensions of maturity or a combination of any of these modifications intended to minimize potential losses. In most instances, interest will continue to be charged on principal balances outstanding during the extended term. Therefore, the financial effects of the recorded investment of loans restructured during the year ended December 31, 2025 were not significant.

The following table sets forth the recorded balance of restructured loans and type of modification by class of loans during the periods presented (dollars in thousands):

There were 17 restructured loans totaling $29.5 million andthree restructured loans totaling $65,000 included in nonperforming assets as of December 31, 2025 and December 31, 2024, respectively.

On an ongoing basis, performance of restructured loans are monitored for subsequent payment default. Payment default is recognized when the borrower is 90 days or more past due. As of December 31, 2025, there were $73,000 restructured loans in default. As of December 31, 2024, there were no restructured loans in default. Payment defaults for restructured loans did not significantly impact the determination of the allowance for loan losses in the periods presented. At December 31, 2025, there were no commitments to lend additional funds to borrowers whose loans had been restructured.

Allowance for Loan Losses

The following tables detail activity in the allowance for loan losses by portfolio segment for the periods presented (in thousands):

(1)Included in charge-offs for the year ended December 31, 2023 is a $788,000 write down to fair value an $8.1 million commercial real estate loan relationship transferred to held for sale.

The accrued interest receivable on our loan receivables is excluded from the allowance for credit loss estimate and is included in interest receivable on our consolidated balance sheets. As of December 31, 2025 and December 31, 2024, the accrued interest on our loan portfolio was $19.6 million and $20.2 million, respectively.

6. PREMISES AND EQUIPMENT

Premises and equipment at December 31, 2025 and 2024 are summarized as follows (in thousands):

Assets with accumulated depreciation of $3.2 million and $851,000 were written off for the years ended December 31, 2025 and 2024, respectively.

Depreciation expense was $7.6 million, $8.3 million and $8.4 million for the years ended December 31, 2025, 2024 and 2023, respectively.

7. DEPOSITS

Deposits in the accompanying consolidated balance sheets are classified as follows (in thousands):

For the years ended December 31, 2025, 2024 and 2023, interest expense on CDs of $250,000 or more was $29.6 million, $21.7 million and $13.0 million, respectively.

At December 31, 2025, the scheduled maturities of CDs, including public accounts, were as follows (in thousands):

Brokered deposits may consist of CDs and non-maturity deposits. At December 31, 2025, we had $19.8 million brokered CDs. Brokered non-maturity deposits were $652.4 million at December 31, 2025 with a weighted average cost of 359 basis points. As of December 31, 2024, we had $115.7 million in brokered CDs and $627.1 million in brokered non-maturity deposits with a weighted average cost of 321 basis points. Our current policy allows for maximum brokered deposits of the lesser of $1.05 billion or 12% of total assets.

At December 31, 2025 and 2024, we had approximately $6.0 million and $7.9 million, respectively, in deposits from related parties, including directors and named executive officers.

The aggregate amount of demand deposit overdrafts that have been reclassified as loans were $1.0 million and $1.2 million at December 31, 2025 and 2024, respectively.

8. BORROWING ARRANGEMENTS

Information related to borrowings is provided in the table below (dollars in thousands):

(1)The average amount outstanding during the period was computed by dividing the total daily outstanding principal balances by the number of days in the period.

(2)The maximum amount outstanding at any month-end during the period.

(3)The weighted average interest rate during the period was computed by dividing the actual interest expense by the average amount outstanding during the period. The weighted average interest rate on FHLB borrowings includes the effect of interest rate swaps.

(4)Stated rate.

(5)The interest rate on FHLB borrowings includes the effect of interest rate swaps.

Maturities of the obligations associated with our borrowing arrangements based on scheduled repayments at December 31, 2025 are as follows (in thousands):

Other borrowings may include federal funds purchased, repurchase agreements and borrowings from the Federal Reserve through the FRDW. Southside Bank hasthree unsecured lines of credit for the purchase of overnight federal funds at prevailing rates with Frost Bank, Amegy Bank, TIB – The Independent Bankers Bank for $40.0 million, $25.0 million and $15.0 million, respectively. There wereno federal funds purchased at December 31, 2025 or 2024. To provide more liquidity in response to economic conditions in recent years, the Federal Reserve has encouraged broader use of the discount window. At December 31, 2025, the amount of additional funding the Bank could obtain from the FRDW, collateralized by securities, was approximately $241.8 million. There were $110.0 million in borrowings from the FRDW at December 31, 2025. There wereno borrowings from the FRDW at December 31, 2024. Southside Bank has a $5.0 million line of credit with Frost Bank to be used to issue letters of credit, and at December 31, 2025, the line hadone outstanding letter of credit for $155,000. Southside Bank currently hastwo outstanding letters of credit from FHLB held as collateral for loans totaling $6.2 million.

Southside Bank enters into sales of securities under repurchase agreements. These repurchase agreements totaled $98.7 million at December 31, 2025, and $76.4 million at December 31, 2024, and had maturities of less thanone year. Repurchase agreements are secured by investment and MBS and are stated at the amount of cash received in connection with the transaction.

FHLB borrowings represent borrowings with fixed interest rates ranging from 1.26% to 4.80% (including the effect of interest rate swaps) and with remaining maturities of 5 days to 2.5 years at December 31, 2025. FHLB borrowings may be collateralized by FHLB stock, nonspecified loans and/or securities. At December 31, 2025, the amount of additional funding Southside Bank could obtain from FHLB was approximately $2.45 billion, net of FHLB stock purchases required.

9. LONG-TERM DEBT

Information related to our long-term debt is summarized as follows for the periods presented (in thousands):

(1)This debt consists of subordinated notes with a remaining maturity greater thanone year that qualify under the risk-based capital guidelines as Tier 2 capital, subject to certain limitations.

(2)The unamortized discount and debt issuance costs reflected in the carrying amount of the subordinated notes totaled approximately$810,000 at December 31, 2025 and$958,000 at December 31, 2024.

(3)The unamortized discount and debt issuance costs reflected in the carrying amount of the subordinated notes totaled approximately $2.5 million at December 31, 2025.

(4)This debt consists of trust preferred securities that qualify under the risk-based capital guidelines as Tier 1 capital, subject to certain limitations.

(5)The unamortized debt issuance costs reflected in the carrying amount of the Southside Statutory Trust III junior subordinated debentures totaled$32,000 at December 31, 2025 and $37,000 at December 31, 2024.

As of December 31, 2025, the details of the subordinated notes and the trust preferred subordinated debentures are summarized below (dollars in thousands):

(1)On April 4, 2024 and June 14, 2023, the Company repurchased $2.0 million and $5.0 million, respectively, of the $100.0 million fixed-to-floating rate subordinated notes that mature on November 15, 2030.

(2)On October 10, 2007, as part of an acquisition we assumed $3.6 million of floating rate junior subordinated debentures issued in 2005 to Magnolia Trust Company I.

On November 6, 2020, the Company issued $100.0 million in aggregate principal amount of fixed-to-floating rate subordinated notes that mature on November 15, 2030. This debt initially charged interest at a fixed rate of 3.875% per year through

November 14, 2025 and thereafter, adjusts quarterly at a floating rate equal to the then current three-month term SOFR, as published by the FRBNY, plus 366 basis points. The proceeds from the sale of the subordinated notes were used for general corporate purposes.

On August 14, 2025, the Company issued $150.0 million in aggregate principal amount of fixed-to-floating rate subordinated notes that mature on August 15, 2035. This debt initially bears interest at a fixed rate of 7.00% per year through August 15, 2030 and thereafter, adjusts quarterly at a floating rate equal to the then current three-month term SOFR, as published by the FRBNY, plus 357 basis points. The proceeds from the sale of the subordinated notes were used for general corporate purposes.

10. EMPLOYEE BENEFITS

Deferred Compensation Agreements

Southside Bank has deferred compensation agreements with 28 of its executive officers, which generally provide for payment of an aggregate amount of $9.3 million over a maximum period of 15 years after retirement or death. Of the 28 executives included in the agreements, payments have commenced tonine former executives and/or their beneficiaries. Deferred compensation expense was $304,000, $330,000 and $86,000 for the years ended December 31, 2025, 2024 and 2023, respectively. At December 31, 2025 and 2024, the deferred compensation plan liability totaled $3.2 million.

Health Insurance

We provide accident and health insurance for substantially all employees through a self-funded insurance program. The cost of health care benefits was $8.7 million, $8.9 million and $8.1 million for the years ended December 31, 2025, 2024 and 2023, respectively.

Employee Stock Ownership Plan

We have an ESOP which covers substantially all employees. Contributions to the ESOP are at the sole discretion of the board of directors. We contributed $1.0 million to the ESOP for the years ended December 31, 2025, 2024 and 2023. At December 31, 2025 and 2024, the ESOP owned 412,155 and 352,473 shares of common stock, respectively. These shares are treated as externally held shares for dividend and earnings per share calculations.

Long-term Disability

We have an officer’s long-term disability income policy which provides coverage in the event they become disabled as defined under its terms. Individuals are automatically covered under the policy if they (a) have been elected as an officer, and (b) have been an employee of Southside Bank forthree years. The policy provides, among other things, that should a covered individual become totally disabled he would receive two-thirds of his current salary, not to exceed $15,000 per month. The benefits paid out of the policy are limited by the benefits paid to the individual under the terms of our other Company-sponsored benefit plans.

Split Dollar Agreements

We have split dollar agreements withsix of our executive officers, two of which were actively employed with us as of December 31, 2025. The agreements provide we will be the beneficiary of BOLI insuring the executives’ lives. The agreements provide the executives the right to designate the beneficiaries of the death benefits guaranteed in each agreement. As of December 31, 2025, the estimated death benefits for thesix executives totaled $6.2 million. The agreements also state that after the executive’s retirement, we shall also pay an annual gross-up bonus to the executive in an amount sufficient to enable the executive to pay federal income tax on both the economic benefit and on the gross-up bonus. The expense required to record the post retirement liability associated with the split dollar post retirement bonuses was $4,000 for the year ended December 31, 2025, and a credit to expense of $28,000 and $95,000 for the years ended December 31, 2024 and 2023, respectively. For the years ended December 31, 2025 and 2024, the split dollar liability totaled $1.6 million.

401(k) Plan

We have a 401(k) Plan covering substantially all employees that permits each participant to make before- or after-tax contributions subject to certain limits imposed by the Internal Revenue Code. Beginning January 1, 2017, eligible employees may participate in the 401(k) Plan after they have worked at least 30 days with the Company. For the years ended December 31, 2025, 2024 and 2023, expense attributable to the 401(k) Plan totaled $2.2 million.

Retirement Plans

We have a defined benefit pension plan pursuant to which participants are entitled to benefits based on final average monthly compensation and years of credited service determined in accordance with plan provisions.

We have a nonfunded supplemental retirement plan for our employees whose benefits under the principal retirement plan are reduced because of compensation deferral elections or limitations under federal tax laws.

Entrance into the Retirement Plan by new employees was frozen effective December 31, 2005. Employees hired after December 31, 2005 are not eligible to participate in the Retirement Plan. All remaining participants in the Retirement Plan are fully vested. Benefits are payable monthly commencing on the later of age 65 or the participant’s date of retirement. Eligible participants may retire at reduced benefit levels after reaching age 55. We contribute amounts to the pension fund sufficient to satisfy funding requirements of the Employee Retirement Income Security Act. Effective December 31, 2020, all future benefit accruals and accrual of benefit service, including consideration of compensation increases, were frozen. No further benefits have been or will be earned by employees since that date.

Retirement Plan assets didnot include any shares of our stock at December 31, 2025 or 2024. During 2025, our funded status improved, and at December 31, 2025, we had a funded status of $10.3 million compared to a funded status of $9.2 million at December 31, 2024. The improvement in the funded status was a result of a greater than expected return on the fair value of plan assets since December 31, 2024, partially offset by a decrease in the discount rate to better reflect the current market conditions at December 31, 2025 compared to December 31, 2024.

In connection with the acquisition of Omni, we acquired the OmniAmerican Bank Defined Benefit Plan which was remeasured at fair value. The Acquired Retirement Plan originally called for benefits to be paid to eligible employees at retirement based primarily upon years of service and the compensation levels at retirement. As of December 31, 2006, the benefits under the Acquired Retirement Plan were frozen by Omni. No further benefits have been or will be earned by employees since that date. In addition, no new participants may be added to the Acquired Retirement Plan after December 31, 2006. During 2025, our funded status remained relatively unchanged with a funded status of $1.1 million at December 31, 2025 and 2024. Subsequent to December 31, 2025, the Acquired Retirement Plan was merged with the Retirement Plan effective January 1, 2026.

We use a measurement date of December 31 for our plans.

Activity in our defined benefit pension plans and restoration plan were as follows (in thousands):

Amounts related to our defined benefit pension plans and restoration plan recognized as a component of other comprehensive income (loss) were as follows (in thousands):

The noncash adjustment to the employee benefit plan assets and/or liabilities, consisting of changes in net loss, was $(2.1) million and $299,000 for the years ended December 31, 2025 and 2024, respectively.

Net amounts recognized in net periodic benefit cost and other comprehensive income (loss) were as follows (in thousands):

Amounts recognized as a component of accumulated other comprehensive income (loss) were as follows (in thousands):

Net periodic pension cost and postretirement benefit cost included the following components (in thousands):

The Retirement Plan and Acquired Retirement Plan assets, which consist primarily of marketable equity and debt instruments, are valued using market quotations in active markets for identical assets, or market quotations for similar assets in active or non-active markets. The Retirement Plans’ obligations and the annual pension expense are determined by independent actuaries and through the use of a number of assumptions. Key assumptions in measuring the Retirement Plans’ obligations include the discount rate and the estimated future return on plan assets.

The discount rate is determined by matching the future benefit payments of the Retirement Plans to a portfolio of high quality corporate bonds as of the measurement date, December 31, 2025. The expected long-term rate of return assumption reflects the average return expected based on the investment strategies and asset allocation of the assets invested to provide for the Retirement Plans’ liabilities. We considered broad equity and bond indices, long-term return projections and actual long-term historical Plan performance when evaluating the expected long-term rate of return assumption.

The assumptions used to determine the benefit obligation were as follows:

The assumptions used to determine net periodic pension cost and postretirement benefit cost were as follows:

Material changes in pension benefit costs may occur in the future due to changes in these assumptions. Future annual amounts could be impacted by changes in the number of Plan participants, changes in the level of benefits provided, changes in the discount rates, changes in the expected long-term rate of return, changes in the level of contributions to the Retirement Plan and other factors.

The major categories of assets in the Plan and the Acquired Retirement Plan are presented in the following table (in thousands). Assets are segregated by the level of the valuation inputs within the fair value hierarchy established by ASC Topic 820 “Fair Value Measurements and Disclosures,” utilized to measure fair value (see “Note 12 – Fair Value Measurement”). Our Restoration Plan is unfunded.

(1)The Acquired Retirement Plan assets were sold in December 2025 in preparation for the merger of the Acquired Retirement Plan with the Retirement Plan on January 1, 2026.

(2)This category consist of pooled separate accounts invested mainly in domestic stocks.

(3)This category is comprised of pooled separate accounts invested in mutual funds and international stocks.

(4)This category consist of pooled separate accounts invested in mutual funds, bonds and fixed income securities.

(5)This category is comprised of a pooled separate account invested in commercial real estate and includes mortgage loans which are backed by the associated properties.

(6)This category is comprised of collective investment funds invested in mutual funds.

(7)Funds invest principally in investment grade debt securities, including U.S. Government obligations, corporate bonds and mortgage and asset backed securities.

We did not have any plan assets with Level 3 input fair value measurements at December 31, 2025 or 2024.

During the year ended December 31, 2024, we liquidated and reinvested the assets in the Retirement Plan using a liability-driven investment strategy. Our overall investment strategy is to realize long-term growth of the Retirement Plan within acceptable risk parameters, while funding benefit payments from dividend and interest income, to the extent possible. The target allocations for plan assets are 86.9% fixed income,11.1% equities and 2.0% cash equivalents. Equity securities are diversified among U.S. and international (both developed and emerging), large, mid and small caps, value and growth securities and REITs. The investment objective of equity funds is long-term capital appreciation with current income. Fixed income securities include government agencies, CDs, corporate bonds, municipal bonds and MBS. The investment objective of fixed income funds is to maximize investment return while preserving investment principal. Mutual funds are primarily used for equity and REITs because of the superior diversification they provide.

As of December 31, 2025, expected future benefit payments related to the Retirement Plan, the Acquired Retirement Plan and the Restoration Plan were as follows (in thousands):

We expect to contribute $1.5 million to our Restoration Plan in 2026. We donot expect to make additional contributions to the Retirement Plan or the Acquired Retirement Plan in 2026.

Share-based Incentive Plans

2025 Incentive Plan

On May 14, 2025, our shareholders approved the 2025 Incentive Plan, which is a stock-based incentive compensation plan. A total of 1,200,000 shares of our common stock were reserved and available for issuance pursuant to awards granted under the 2025 Incentive Plan. Under the 2025 Incentive Plan, we are authorized to grant stock options, stock appreciation rights, restricted stock, restricted stock units, deferred stock units, performance awards, other stock-based awards, or any other right or interest relating to stock or cash, granted to selected employees, officers, directors or consultants of the Company and its affiliates. As of December 31, 2025, there were 1.1 million shares remaining available for grant for future awards.

All share data has been adjusted to give retroactive recognition to stock dividends, where applicable. Reference to incentive plans refers to the 2025 Incentive Plan and predecessor incentive plans.

Share-based compensation expense related to incentive plans and related income tax benefit are presented in the following table (in thousands):

Unrecognized compensation expense related to incentive plans and related income tax benefit are presented in the following table (in thousands):

The fair value of each NQSO is estimated on the date of grant using a Black-Scholes option pricing model. There wereno NQSO grants during the years ended December 31, 2025, 2024 or 2023. The NQSOs have contractual terms of 10 years and vest in equal annual installments over either athree- orfour-year period.

The fair value of each RSU is the ending stock price on the date of grant. RSUs granted to employees vest in equal annual installments over a period of between three andfour years. Director RSUs vest after a period ofone year. Directors may elect to defer the receipt of shares and instead receive them on a specified anniversary of grant date or upon the termination of their service on the Board.

The fair value of each PSU is the ending stock price on the date of grant. PSUs granted to executive officers will cliff vest on the third anniversary of the grant date, subject to the grantee’s continued service on such date, and will be earned based on the Company’s ROATCE related to ROATCE of the KBW Nasdaq Regional Bank Index (NASDAQ: KRX), over a 3 year performance period. The PSUs may be earned between a minimum payout of 50%, based on a ROATCE performance threshold of 25th percentile of the Peer Group, a target payout of 100%, based on a ROATCE performance threshold of 50th percentile, and a maximum payout of 150%, based on a performance threshold of 75th percentile or greater. Share payout for performance between the minimum threshold, target and maximum is calculated on a straight line basis, and performance below the minimum threshold results in no share payout.

Each award is evidenced by an award agreement that specifies the option price, if applicable, the duration of the award, the number of shares to which the award pertains and such other provisions as the board of directors determines. Historically, shares issued in connection with stock compensation awards have been issued from available authorized shares. Beginning in the second quarter of 2017, shares were issued from available treasury shares.

Shares issued in connection with stock compensation awards along with other related information are presented in the following table (in thousands, except share amounts):

A combined summary of activity in our share-based plans as of December 31, 2025 is presented below. Performance stock units outstanding are presented assuming attainment of the maximum payout rate as set forth by the performance criteria:

Other information regarding options outstanding and exercisable as of December 31, 2025 is as follows:

The total intrinsic value of outstanding in-the-money stock options and outstanding in-the-money exercisable stock options was $4,000 for both at December 31, 2025. The weighted-average remaining contractual life of options exercisable at December 31, 2025 was 2.7 years.

11. DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES

Our hedging policy allows the use of interest rate derivative instruments to manage our exposure to interest rate risk or hedge specified assets and liabilities. These instruments may include interest rate swaps and interest rate caps and floors. All derivative instruments are carried on the balance sheet at their estimated fair value and are recorded in other assets or other liabilities, as appropriate. Derivative instruments may be designated as cash flow hedges of variable rate assets or liabilities, cash flow hedges of forecasted transactions, fair value hedges of a recognized asset or liability or as non-hedging instruments.

Cash Flow Hedges

Gains and losses on derivative instruments designated as cash flow hedges are recorded in AOCI to the extent they are effective. If the hedge is effective, the amount recorded in other comprehensive income is reclassified to interest expense in the same periods that the hedged cash flows impact earnings. We have entered into certain interest rate swap contracts on specific variable rate agreements and fixed rate short-term pay agreements with third-parties. These interest rate swap contracts were designated as hedging instruments in cash flow hedges under ASC Topic 815. The objective of the interest rate swap contracts is to manage the expected future cash flows on $860.0 million of Bank liabilities. The cash flows from the swap contracts are expected to be highly effective in hedging the variability in future cash flows attributable to fluctuations in the underlying SOFR rate. At December 31, 2025, the net losses recognized in AOCI that are expected to be reclassified into earnings within the next 12 months were $367,000.

In accordance with ASC Topic 815, if a hedging item is terminated prior to maturity for a cash settlement, the existing gain or loss within AOCI will continue to be reclassified into earnings during the period or periods in which the hedged forecasted transaction affects earnings unless it is probable that the forecasted transaction will not occur by the end of the originally specified time period. These transactions are reevaluated on a monthly basis to determine if the hedged forecasted transactions are still probable of occurring. If at a subsequent evaluation, it is determined that the transactions are probable of not occurring, any related gains or losses recorded in AOCI are immediately recognized in earnings. During the third quarter of 2024, we terminated three interest rate swap contracts designated as cash flow hedges, and during the second quarter of 2023, we terminatedone interest rate swap contract designated as a cash flow hedge. At the time of termination, we determined the hedged forecasted transactions were still probable of occurring. The existing loss in AOCI will be reclassified into earnings in the same periods the hedged forecasted transaction affects earnings.

Fair Value Hedges

Gains and losses on derivative instruments designated as fair value hedges, as well as the change in fair value of the hedged item, are recorded in interest income in the consolidated statements of income. Gains and losses due to changes in fair value of the interest rate swap agreements offset changes in the fair value of the hedged portion of the hedged item. We have partial term fair value hedges for certain of our fixed rate callable AFS municipal securities and partial term fair value hedges of fixed rate AFS MBS and fixed rate loans using the portfolio layer method. This approach allows us to designate as the hedged item a stated amount of the assets that are not expected to be affected by prepayments, defaults and other factors affecting the timing and amount of cash flows. The fair value portfolio level hedging adjustment on our hedged MBS portfolio and hedged loan portfolio has not been attributed to the individual AFS securities or individual loans in our balance sheet. The instruments are designated as fair value hedges as the changes in the fair value of the interest rate swap are expected to partially offset changes in the fair value of the hedged item attributable to changes in the SOFR swap rate, the designated benchmark interest rate. These derivative contracts involve the receipt of floating rate interest from a counterparty in exchange for us making fixed-rate payments over the life of the agreement, without the exchange of the underlying notional value. Over the years, we terminated some of our securities fair value hedging relationships and sold the majority of the hedged items. As a result of the sale, during the year ended December 31, 2025 the cumulative adjustment to the carrying amount was a fair value loss of $1.2 million recognized in earnings and recorded in noninterest income. During the years ended December 31, 2024 and 2023, the cumulative adjustments to the carrying amount was a fair value net gain of $3.5 million and $6.5 million, respectively, recognized in earnings and recorded in noninterest income.

The following table presents the amounts recorded in the consolidated balance sheets related to the cumulative adjustments for fair value hedges (in thousands):

(1) Amounts include the amortized cost basis of closed portfolios used to designate hedging relationships under the portfolio layer method. The hedged item is a layer of the closed portfolio which is expected to be remaining at the end of the hedging relationship. As of December 31, 2025 and December 31, 2024, the amortized cost basis of the closed MBS portfolio used in these hedging relationships was $1.07 billion and $558.5 million, respectively, the amount of the designated hedged items were $301.0 million and $134.0 million, respectively, and the cumulative amount of fair value hedging adjustments associated with these MBS hedging relationships was a gain of $789,000 and $1.1 million, respectively. As of December 31, 2025 and December 31, 2024, the amortized cost basis of the closed loan portfolio used in these hedging relationships was $240.0 million and $265.8 million, respectively, the amount of the designated hedged items were $155.0 million for both periods, and the cumulative amount of fair value hedging adjustments associated with these loan hedging relationships was a loss of $58,000 and a gain of $1.5 million, respectively.

(2) Excludes fair value hedging adjustments.

(3) Excluded from the table above are the cumulative amount of fair value hedging adjustments for securities AFS and loans for which hedge accounting has been discontinued in the amounts of a loss of $740,000 and a loss of $3.0 million, respectively, at December 31, 2025, and a loss of $4.8 million and a loss of $3.7 million, respectively, at December 31, 2024.

Derivatives Designated as Non-Hedging Instruments

From time to time, we may enter into certain interest rate swaps, cap and floor contracts that are not designated as hedging instruments. These interest rate derivative contracts relate to transactions in which we enter into an interest rate swap, cap or floor with a customer while concurrently entering into an offsetting interest rate swap, cap or floor with a third-party financial institution. We agree to pay interest to the customer on a notional amount at a variable rate and receive interest from the customer on a similar notional amount at a fixed interest rate. At the same time, we agree to pay a third-party financial institution the same fixed interest rate on the same notional amount and receive the same variable interest rate on the same notional amount. These interest rate derivative contracts allow our customers to effectively convert a variable rate loan to a fixed rate loan. The changes in the fair value of the underlying derivative contracts primarily offset each other and do not significantly impact our results of operations. We recognized swap fee income associated with these derivative contracts immediately based upon the difference in the bid/ask spread of the underlying transactions with the customer and the third-party financial institution. The swap fee income is included in other noninterest income in our consolidated statements of income.

At December 31, 2025 and 2024, net derivative assets included $5.5 million and $49.9 million, respectively, of cash collateral received from counterparties under master netting agreements.

The notional amounts of the derivative instruments represent the contractual cash flows pertaining to the underlying agreements. These amounts are not exchanged and are not reflected in the consolidated balance sheets. The fair value of the interest rate swaps are presented at net in other assets and other liabilities and in the net change in each of these financial statement line items in the accompanying consolidated statements of cash flows when a right of offset exists, based on transactions with a single counterparty that are subject to a legally enforceable master netting agreement.

The following tables present the notional and estimated fair value amount of derivative positions outstanding (in thousands):

(1)Notional amounts, which represent the extent of involvement in the derivatives market, are used to determine the contractual cash flows required in accordance with the terms of the agreement. These amounts are typically not exchanged, significantly exceed amounts subject to credit or market risk and are not reflected in the consolidated balance sheets.

(2)Net derivative assets are included in other assets and net derivative liabilities are included in other liabilities on the consolidated balance sheets. Included in the fair value of net derivative assets and net derivative liabilities are credit valuation adjustments reflecting counterparty credit risk and our credit risk. At December 31, 2025, we had $612,000 credit exposure related to interest rate swaps with financial institutions and $7.1 million related to interest rate swaps with customers. At December 31, 2024, we hadno credit exposure related to interest rate swaps with financial institutions and $1.3 million related to interest rate swaps with customers. The credit risk associated with customer transactions is partially mitigated as these are generally secured by the non-cash collateral securing the underlying transaction being hedged.

The summarized expected weighted average remaining maturity of the notional amount of interest rate swaps and the weighted average interest rates associated with the amounts expected to be received or paid on interest rate swap agreements are presented below (dollars in thousands). Variable rates received on fixed pay swaps are based on overnight SOFR rates in effect at December 31, 2025 and December 31, 2024:

The following table presents amounts included in the consolidated statements of income related to interest rate swap agreements (in thousands):

12. FAIR VALUE MEASUREMENT

Fair value is the price that would be received upon the sale of an asset or paid to transfer a liability (exit price) in an orderly transaction between market participants. A fair value measurement assumes 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 in the principal (or most advantageous) market used to measure the fair value of the asset or liability is not 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 is not 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.

Valuation techniques including the market approach, the income approach and/or the cost approach are utilized to determine fair value. Inputs to valuation techniques refer to the assumptions market participants would use in pricing the asset or liability. Valuation policies and procedures are determined by our investment department and reported to our ALCO for review. An entity must consider all aspects of nonperforming risk, including the entity’s own credit standing, when measuring fair value of a 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 the reporting entity’s own assumptions about the assumptions market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. A fair value hierarchy for valuation inputs 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:

Level 1 Inputs - Unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date.

Level 2 Inputs - Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. These might include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (such as interest rates, volatilities, prepayment speeds, credit risks, etc.) or inputs that are derived principally from or corroborated by market data by correlation or other means.

Level 3 Inputs - Unobservable inputs for determining the fair values of assets or liabilities that reflect an entity’s own assumptions about the assumptions that market participants would use in pricing the assets or liabilities.

Certain financial assets are measured at fair value in accordance with GAAP. Adjustments to the fair value of these assets usually result from the application of fair value accounting or write-downs of individual assets. A description of the valuation methodologies used for assets and liabilities measured at fair value, as well as the general classification of such instruments pursuant to the valuation hierarchy, is set forth below.

Securities AFS and Equity Investments with readily determinable fair values – U.S. Treasury securities and equity investments with readily determinable fair values are reported at fair value utilizing Level 1 inputs. Other securities classified as AFS are reported at fair value utilizing Level 2 inputs. For most of these securities, we obtain fair value measurements from independent pricing services and obtain an understanding of the pricing methodologies used by these independent pricing services. The fair value measurements consider observable data that may include dealer quotes, market spreads, cash flows, the U.S. Treasury yield curve, live trading levels, trade execution data, market consensus prepayment speeds, credit information and the bond’s terms and conditions, among other things, as stated in the pricing methodologies of the independent pricing services.

We review and validate the prices supplied by the independent pricing services for reasonableness by comparison to prices obtained from, in some cases, two additional third-party sources. For securities where prices are outside a reasonable range, we further review those securities, based on internal ALCO approved procedures, to determine what a reasonable fair value measurement is for those securities, given available data.

Derivatives – Derivatives are reported at fair value utilizing Level 2 inputs. We obtain fair value measurements fromtwo sources including an independent pricing service and the counterparty to the derivatives designated as hedges. The fair value measurements consider observable data that may include dealer quotes, market spreads, the U.S. Treasury yield curve, live trading levels, trade execution data, credit information and the derivatives’ terms and conditions, among other things. We review the prices supplied by the sources for reasonableness. In addition, we obtain a basic understanding of their underlying pricing methodology. We validate prices supplied by the sources by comparison to one another.

Certain nonfinancial assets and nonfinancial liabilities measured at fair value on a recurring basis include reporting units measured at fair value and tested for goodwill impairment.

Certain financial assets and financial liabilities are measured at fair value on a nonrecurring basis, which means that the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances (for example, when there is evidence of impairment). Financial assets and financial liabilities measured at fair value on a nonrecurring basis included foreclosed assets and collateral-dependent loans at December 31, 2025 and 2024.

Foreclosed Assets – Foreclosed assets are initially recorded at fair value less costs to sell. The fair value measurements of foreclosed assets can include Level 2 measurement inputs such as real estate appraisals and comparable real estate sales information, in conjunction with Level 3 measurement inputs such as cash flow projections, qualitative adjustments and sales cost estimates. As a result, the categorization of foreclosed assets is Level 3 of the fair value hierarchy. In connection with the measurement and initial recognition of certain foreclosed assets, we may recognize charge-offs through the allowance for credit losses.

Collateral-Dependent Loans – Certain loans may be reported at the fair value of the underlying collateral if repayment is expected substantially from the operation or sale of the collateral. Collateral values are estimated using Level 3 inputs based on customized discounting criteria or appraisals. At December 31, 2025 and 2024, the impact of the fair value of collateral-dependent loans was reflected in our allowance for loan losses.

The fair value estimate of financial instruments for which quoted market prices are unavailable is dependent upon the assumptions used. Consequently, those estimates cannot be substantiated by comparison to independent markets and, in many cases, could not be realized in immediate settlement of the instruments. Accordingly, the aggregate fair value amounts presented in the fair value tables do not necessarily represent their underlying value.

The following tables summarize assets measured at fair value on a recurring and nonrecurring basis segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value (in thousands):

(1)All MBS are issued and/or guaranteed by U.S. government agencies or U.S. GSEs.

(2)Consists of individually evaluated loans. Loans for which the fair value of the collateral and commercial real estate fair value of the properties is less than cost basis are presented net of allowance. Losses on these loans represent charge-offs which are netted against the allowance for loan losses.

Disclosure of fair value information about financial instruments, whether or not recognized in the balance sheet, is required when it is practicable to estimate that value. In cases where quoted market prices are not available, fair values are based on estimates using present value or other estimation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Such techniques and assumptions, as they apply to individual categories of our financial instruments, are as follows:

Cash and cash equivalents – The carrying amount for cash and cash equivalents is a reasonable estimate of those assets’ fair value.

Investment and MBS HTM – Fair values for these securities are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices for similar securities or estimates from independent pricing services.

FHLB stock – The carrying amount of FHLB stock is a reasonable estimate of the fair value of those assets.

Equity investments– The carrying value of equity investments without readily determinable fair values are measured at cost less impairment, if any, adjusted for observable price changes for an identical or similar investment of the same issuer. This carrying value is a reasonable estimate of the fair value of those assets.

Loans receivable –We estimate the fair value of our loan portfolio to an exit price notion with adjustments for liquidity, credit and prepayment factors. Nonperforming loans continue to be estimated using discounted cash flow analyses or the underlying value of the collateral where applicable.

Loans held for sale – The fair value of loans held for sale is determined based on expected proceeds, which are based on sales contracts and commitments.

Deposit liabilities – The fair value of demand deposits, savings accounts and certain money market deposits is the amount on demand at the reporting date, which is the carrying value. Fair values for fixed rate CDs are estimated using a discounted cash flow calculation that applies interest rates currently being offered for deposits of similar remaining maturities.

Other borrowings– Federal funds purchased generally have original terms to maturity of one day and repurchase agreements generally have terms of less than one year, and therefore both are considered short-term borrowings. Consequently, their carrying value is a reasonable estimate of fair value. Borrowings from the Federal Reserve through the FRDW have original maturities of one year or less, and the fair value is estimated by discounting the future cash flows using rates at which borrowings would be made to borrowers with similar credit ratings and for the same remaining maturities.

FHLB borrowings– The fair value of these borrowings is estimated by discounting the future cash flows using rates at which borrowings would be made to borrowers with similar credit ratings and for the same remaining maturities.

Subordinated notes– The fair value of the subordinated notes is estimated by discounting future cash flows using estimated rates at which long-term debt would be made to borrowers with similar credit ratings and for the remaining maturities.

Trust preferred subordinated debentures – The fair value of the long-term debt is estimated by discounting future cash flows using estimated rates at which long-term debt would be made to borrowers with similar credit ratings and for the remaining maturities.

The following tables present our financial assets and financial liabilities measured on a nonrecurring basis at both their respective carrying amounts and estimated fair value (in thousands):

13. SHAREHOLDERS’ EQUITY

Cash dividends declared and paid were $1.44, $1.44 and $1.42 per share for the years ended December 31, 2025, 2024 and 2023, respectively. Future dividends will depend on our earnings, financial condition and other factors which the board of directors considers to be relevant. Our dividend policy requires that any cash dividend payments made may not exceed consolidated earnings for that year.

We are subject to various regulatory capital requirements administered by the federal banking agencies. Failure to meet minimum capital requirements can initiate certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on our financial statements. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, we must meet specific capital guidelines that involve quantitative measures of our assets, liabilities and certain off-balance-sheet items as calculated under regulatory accounting practices. Our capital amounts and classification are also subject to qualitative judgments by the regulators regarding components, risk weightings and other factors.

Quantitative measures established by regulation to ensure capital adequacy require us to maintain minimum amounts and ratios (set forth in the table below) of Common Equity Tier 1, Tier 1 and Total Capital (as defined in the regulations) to risk-weighted assets (as defined) and of Tier 1 Capital (as defined) to average assets (as defined). At December 31, 2025, we exceeded all regulatory minimum capital requirements.

As of December 31, 2025, the most recent notification from the FDIC categorized us as well capitalized under the regulatory framework for prompt corrective action. To be categorized as well capitalized we must maintain minimum Common Equity Tier 1 risk-based, Tier 1 risk-based, Total risk-based and Tier 1 leverage ratios as set forth in the following table (dollars in thousands). There are no conditions or events since that notification that management believes have changed our category.

(1)Refers to quarterly average assets as calculated in accordance with policies established by bank regulatory agencies.

Our payment of dividends is limited under regulation. The amount that can be paid in any calendar year without prior approval of our regulatory agencies cannot exceed the lesser of net profits (as defined) for that year plus the net profits for the preceding two calendar years or retained earnings.

14. DIVIDEND REINVESTMENT AND COMMON STOCK REPURCHASE PLAN

We have in effect a DRIP which allows enrolled shareholders to reinvest dividends paid to them by the Company into new shares of our stock. The DRIP is funded by stock authorized but not yet issued. For the year ended December 31, 2025,32,086 shares were issued under this plan at an average price per share of $29.73, reflective of other trades at the time of each sale. For the years ended December 31, 2024 and December 31, 2023,38,286 and 38,884 shares, respectively, were issued under this plan at an average price per share of $30.29 and $31.48, respectively, reflective of other trades at the time of each sale.

We repurchased 820,931 shares of our common stock at a cost of $23.4 million during the year ended December 31, 2025,57,966 shares of common stock at a cost of $1.5 million during the year ended December 31, 2024, and 1,435,193 shares of common stock at a cost of $45.1 million during the year ended December 31, 2023. Repurchased shares are designated as treasury shares and are available for general corporate purposes, which may include possible use in connection with our share-based incentive plans and other distributions. Our board of directors continually evaluates the Company's capital needs and those of the Bank and may, at its discretion, initiate, modify or discontinue an authorized repurchase plan without notice.

15. INCOME TAXES

The income tax expense included in the accompanying consolidated statements of income consists of the following (in thousands):

The components of the net deferred tax asset/liability as of December 31, 2025 and 2024 are summarized below (in thousands):

A reconciliation of tax at statutory rates and total tax expense is as follows (dollars in thousands):

(1) State taxes in Texas made up the majority (greater than 50%) of the tax effect in this category.

We file income tax returns in the U.S. federal jurisdiction and in certain states. Federal taxes paid, net of refunds, totaled $12.0 million for the year December 31, 2025, and state income taxes paid, net of refunds, totaled $1.0 million for the year ended December 31, 2025, of which $936,000 was for the state of Texas. We are no longer subject to U.S. federal income tax examinations by tax authorities for years before 2022 or Texas state tax examinations by tax authorities for years before 2021. No valuation allowance was recorded at December 31, 2025 or 2024 as management believes it is more likely than not that all of the deferred tax asset items will be realized in future years. Unrecognized tax benefits were not material at December 31, 2025 or 2024.

16. LEASES

We lease certain retail- and full-service branch locations, ATM locations and certain equipment. Short-term leases, leases with an initial term of 12 months or less and do not contain a purchase option that is likely to be exercised, are not recorded on the balance sheet. Operating lease cost, which is comprised of the amortization of the ROU asset and the implicit interest accreted on the operating lease liability, is recognized on a straight-line basis over the lease term and is included in net occupancy expense on our consolidated statements of income. We evaluate the lease term by assuming the exercise of options to extend that are reasonably assured and those option periods covered by an option to terminate the lease, if deemed not reasonably certain to be exercised. The lease term is used to determine the straight-line expense and limits the depreciable life of any related leasehold improvements. Certain leases require us to pay real estate taxes, insurance, maintenance and other operating expenses associated with the leased premises. These expenses are classified in net occupancy expense on our consolidated statements of income, consistent with similar costs for owned locations, but is not included in operating lease cost below.

Our leases have remaining lease terms ranging from 2 months to 14.7 years, some of which include options to extend for up to 10 years, and some of which include options to terminate within 90 days. We calculate the lease liability using a discount rate that represents our incremental borrowing rate at the lease commencement date.

Balance sheet information related to leases was as follows (in thousands):

The components of lease cost were as follows (in thousands):

Supplemental cash flow information related to leases was as follows (in thousands):

Additional information related to leases was as follows:

Future minimum rental commitments due under non-cancelable operating leases at December 31, 2025 were as follows (in thousands):

We also lease certain of our owned facilities or portions thereof to third parties. Our primary leased facility is a 202,000 square-foot office building in Fort Worth, Texas that is used for a branch location and certain bank operations. We occupy approximately 35,000 square feet of the building and lease the remaining space to various tenants. Some of these leases contain options to extend and options to terminate at the discretion of the tenant.

Operating lease income received from tenants who rent our properties is reported as a reduction to occupancy expense on our consolidated statements of income. The underlying assets associated with these operating leases are included in premises and equipment on our consolidated balance sheets.

Gross rental income from these leases were as follows (in thousands):

At December 31, 2025, non-cancelable operating leases with future minimum lease payments are as follows (in thousands):

17. OFF-BALANCE-SHEET ARRANGEMENTS, COMMITMENTS AND CONTINGENCIES

Financial Instruments with Off-Balance-Sheet Risk. In the normal course of business, we are a party to certain financial instruments with off-balance-sheet risk to meet the financing needs of our customers. These off-balance-sheet instruments include commitments to extend credit and standby letters of credit. These instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount reflected in the financial statements. The contract or notional amounts of these instruments reflect the extent of involvement and exposure to credit loss that we have in these particular classes of financial instruments. The allowance for credit losses on these off-balance-sheet credit exposures is calculated using the same methodology as loans including a conversion or usage factor to anticipate ultimate exposure and expected losses and is included in other liabilities on our consolidated balance sheets.

Allowance for off-balance-sheet credit exposures were as follows (in thousands):

Contractual commitments to extend credit are agreements to lend to a customer provided the terms established in the contract are met. Commitments to extend credit generally have fixed expiration dates and may require the payment of fees. Since some commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. Standby letters of credit are conditional commitments issued to guarantee the performance of a customer to a third party. These guarantees are primarily issued to support public and private borrowing arrangements. The credit risk involved in issuing letters of credit is essentially the same as that involved in commitments to extend credit and similarly do not necessarily represent future cash obligations.

Financial instruments with off-balance-sheet risk were as follows (in thousands):

We apply the same credit policies in making commitments to extend credit and standby letters of credit as we do for on-balance-sheet instruments. We evaluate each customer’s creditworthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary, upon extension of credit is based on management’s credit evaluation of the borrower. Collateral held varies but may include cash or cash equivalents, negotiable instruments, real estate, accounts receivable, inventory, oil, gas and mineral interests, property, plant and equipment.

Securities. In the normal course of business we buy and sell securities. At December 31, 2025 and December 31, 2024, there wereno unsettled trades to purchase securities andno unsettled trades to sell securities.

Deposits. There wereno unsettled issuances of brokered CDs at December 31, 2025 or December 31, 2024.

Litigation. We are involved with various litigation in the normal course of business. Management, after consulting with our legal counsel, believes that any liability resulting from litigation will not have a material effect on our financial position, results of operations or liquidity.

18. SIGNIFICANT GROUP CONCENTRATIONS OF CREDIT RISK

Although we have a diversified loan portfolio, a significant portion of our loans are collateralized by real estate. Repayment of these loans is in part dependent upon the economic conditions in the market area. Our market areas primarily include East and Southeast Texas, as well as the greater Dallas-Fort Worth, Austin and Houston, Texas areas. Part of the risk associated with real estate loans has been mitigated since 18.2% of this group represents loans collateralized by residential dwellings that are primarily owner occupied. Losses on this type of loan have historically been less than those on speculative properties. Many of the remaining real estate loans are collateralized primarily with non-owner occupied commercial real estate.

The MBS we hold consist exclusively of U.S. agency securities which are either directly or indirectly backed by the full faith and credit of the U.S. Government or guaranteed by GSEs. The GNMA MBS are backed by the full faith and credit of the U.S. Government. The Fannie Mae and Freddie Mac U.S. agency GSE guaranteed MBS are not backed by the full faith and credit of the U.S. government.

19. SEGMENT REPORTING

Operating segments are components of a public entity about which separate financial information is available that is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and in assessing performance. The Bank is the only significant subsidiary upon which management makes decisions regarding how to allocate resources and assess performance. Individual bank branches across our market areas offer a full range of financial services to individuals, businesses, municipal entities and nonprofit organizations in the communities that we serve. These services include consumer and commercial loans, deposit accounts, wealth management, trust and brokerage services.

Our consumer loan services include 1-4 family residential loans, home equity loans, home improvement loans, automobile loans and other consumer related loans. Commercial loan services include short-term working capital loans for inventory and accounts receivable, short- and medium-term loans for equipment or other business capital expansion, commercial real estate loans and municipal loans. We also offer construction loans for 1-4 family residential and commercial real estate.

We offer a variety of deposit accounts with a wide range of interest rates and terms, including savings, money market, interest and noninterest bearing checking accounts and CDs.

Our trust and wealth management services include investment management, administration of irrevocable, revocable and testamentary trusts, estate administration, and custodian services, primarily for individuals and, to a lesser extent, partnerships and corporations. Additionally, we offer retirement and employee benefit accounts, including but not limited to, IRAs, 401(k) plans and profit-sharing plans.

While the chief operating decision maker monitors the revenue streams of the various products and services, operations are managed and financial performance is evaluated on a Company-wide basis. The Company has determined that all of its market areas consisting of East Texas, Southeast Texas, as well as the greater Dallas-Fort Worth, Austin and Houston, Texas areas, meet the aggregation criteria in accordance with GAAP since each of its banking market areas offer similar products and services, operate in a similar manner, have similar customers, report to the same regulatory authority and are located in a single geographic area (Texas). Accordingly, all of the community banking services and branch locations are considered by management to be aggregated into one reportable operating segment, community banking. The Company’s chief operating decision maker, the President and Chief Executive Officer, uses consolidated net income results to make operating and strategic decisions. See the consolidated statements of income for significant expenses and net income. The measure of segment assets is reported on the consolidated balance sheets as total assets.

The accounting policies are described in the summary of significant accounting policies. Refer to “Note 1 – Summary of Significant Accounting and Reporting Policies” to our consolidated financial statements included in this report for a detailed description of our accounting policies.

20. PARENT COMPANY FINANCIAL INFORMATION

Condensed financial information for Southside Bancshares, Inc. (parent company only) was as follows (in thousands, except share amounts):

CONDENSED STATEMENTS OF INCOME

CONDENSED STATEMENTS OF CASH FLOWS

21. SUBSEQUENT EVENTS

Subsequent to December 31, 2025, on February 15, 2026, the Company completed the redemption of the 3.875% Fixed to Floating Rate Subordinated Notes due 2030 in the aggregate principal amount of $100.0 million. The $100.0 million principal amount included $7.0 million of the notes previously repurchased by the Company. The notes were redeemed in full at 100% of the principal amount plus any accrued and unpaid interest. The remaining unamortized discount and debt issuance costs associated with these notes of approximately $791,000 will be recorded on our consolidated income statements as loss on redemption of subordinated notes in noninterest expense during the first quarter of 2026.