CULLEN/FROST BANKERS, INC.

(Table amounts in thousands, except for share and per share amounts)

Note 1 -Significant Accounting Policies

Nature of Operations. Cullen/Frost Bankers, Inc. (“Cullen/Frost”) is a financial holding company and a bank holding company headquartered in San Antonio, Texas that provides, through its subsidiaries, a broad array of products and services throughout numerous Texas markets. The terms “Cullen/Frost,” “the Corporation,” “we,” “us,” and “our” mean Cullen/Frost Bankers, Inc., and its subsidiaries, when appropriate. In addition to general commercial and consumer banking, other products and services offered include trust and investment management, insurance, brokerage, mutual funds, leasing, treasury management, capital markets advisory and item processing.

Basis of Presentation. The consolidated financial statements in this Quarterly Report on Form 10-Q include the accounts of Cullen/Frost and all other entities in which Cullen/Frost has a controlling financial interest. All significant intercompany balances and transactions have been eliminated in consolidation. The accounting and financial reporting policies we follow conform, in all material respects, to accounting principles generally accepted in the United States and to general practices within the financial services industry.

The consolidated financial statements in this Quarterly Report on Form 10-Q have not been audited by an independent registered public accounting firm, but in the opinion of management, reflect all adjustments necessary for a fair presentation of our financial position and results of operations. All such adjustments were of a normal and recurring nature. The consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q adopted by the Securities and Exchange Commission (“SEC”). Accordingly, the financial statements do not include all of the information and footnotes required by accounting principles generally accepted in the United States for complete financial statements and should be read in conjunction with our consolidated financial statements, and notes thereto, for the year ended December 31, 2024, included in our Annual Report on Form 10-K filed with the SEC on February 6, 2025 (the “2024 Form 10-K”). Operating results for the interim periods disclosed herein are not necessarily indicative of the results that may be expected for a full year or any future period.

Use of Estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates. The allowance for loan losses and the fair values of financial instruments and the status of contingencies are particularly subject to change.

Cash Flow Reporting. Additional cash flow information was as follows:

Accounting Changes, Reclassifications and Restatements. Certain items in prior financial statements have been reclassified to conform to the current presentation. As noted in our 2024 Form 10-K, we adopted ASU No. 2023-07,“Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures,”for our annual financial statements in 2024. ASU 2023-07 became effective for interim periods in 2025. See Note 14 - Operating Segments.

Note 2 -Securities

Securities - Held to Maturity. A summary of the amortized cost, fair value and allowance for credit losses related to securities held to maturity as of September 30, 2025 and December 31, 2024, is presented below.

All mortgage-backed securities included in the above table were issued by U.S. government agencies and corporations. The carrying value of held-to-maturity securities pledged to secure public funds, trust deposits, repurchase agreements and for other purposes, as required or permitted by law totaled $1.3 billion at September 30, 2025 and $1.4 billion December 31, 2024. Accrued interest receivable on held-to-maturity securities totaled $19.6 million at September 30, 2025 and $37.8 million at December 31, 2024, and is included in accrued interest receivable and other assets in the accompanying consolidated balance sheets.

The following table summarizes Moody's and/or Standard & Poor's bond ratings for our portfolio of held-to-maturity securities issued by States and political subdivisions and other securities as of September 30, 2025 and December 31, 2024:

The following table details activity in the allowance for credit losses on held-to-maturity securities during thethree and nine months ended September 30, 2025 and 2024.

Securities - Available for Sale. A summary of the amortized cost, fair value and allowance for credit losses related to securities available for sale as of September 30, 2025 and December 31, 2024, is presented below.

All mortgage-backed securities included in the above table were issued by U.S. government agencies and corporations. At September 30, 2025, all of the securities in our available for sale municipal bond portfolio were issued by the State of Texas or political subdivisions or agencies within the State of Texas, of which approximately 72.6% are either guaranteed by the Texas Permanent School Fund (“PSF”) or have been pre-refunded. Securities with limited marketability, such as stock in the Federal Reserve Bank and the Federal Home Loan Bank, are carried at cost and are reported as other available for sale securities in the table above. The carrying value of available-for-sale securities pledged to secure public funds, trust deposits, repurchase agreements and for other purposes, as required or permitted by law totaled $6.2 billion at both September 30, 2025 and December 31, 2024. Accrued interest receivable on available-for-sale securities totaled $84.1 million at September 30, 2025 and $104.9 million at December 31, 2024, respectively, and is included in accrued interest receivable and other assets in the accompanying consolidated balance sheets.

The table below summarizes, as of September 30, 2025, securities available for sale in an unrealized loss position for which an allowance for credit losses has not been recorded, aggregated by type of security and length of time in a continuous unrealized loss position.

As of September 30, 2025, no allowance for credit losses has been recognized on available for sale securities in an unrealized loss position as management does not believe any of the securities are impaired due to reasons of credit quality. This is based upon our analysis of the underlying risk characteristics, including credit ratings, and other qualitative factors related to our available for sale securities and in consideration of our historical credit loss experience and internal forecasts. The issuers of these securities continue to make timely principal and interest payments under the contractual terms of the securities. Furthermore, management does not have the intent to sell any of the securities classified as available for sale in the table above and believes that it is more likely than not that we will not have to sell any such securities before a recovery of cost. The unrealized losses are due to increases in market interest rates over the yields available at the time the underlying securities were purchased. The fair value is expected to recover as the securities approach their maturity date or repricing date or if market yields for such investments decline.

Contractual Maturities. The following table summarizes the maturity distribution schedule of securities held to maturity and securities available for sale as of September 30, 2025. Mortgage-backed securities are included in maturity categories based on their stated maturity date. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations. Other securities classified as available for sale include stock in the Federal Reserve Bank and the Federal Home Loan Bank, which have no maturity date. These securities have been included in the total column only.

Sales of Securities. Sales of available for sale securities were as follows:

Premiums and Discounts. Premium amortization and discount accretion included in interest income on securities was as follows:

Trading Account Securities. Trading account securities, at estimated fair value, were as follows:

Net gains and losses on trading account securities included in other non-interest income were as follows:

Note 3 -Loans

Loans were as follows:

Concentrations of Credit. Most of our lending activity occurs within the State of Texas, including the four largest metropolitan areas of Austin, Dallas/Ft. Worth, Houston, and San Antonio, as well as other markets. The majority of our loan portfolio consists of commercial and industrial and commercial real estate loans. As of September 30, 2025, there wereno concentrations of loans related to any single industry in excess of 10% of total loans. At that date, the largest industry concentrations were related to the energy industry, which totaled 5.8% of total loans, and the automobile dealerships industry, which totaled 5.3% of total loans. Unfunded commitments to extend credit and standby letters of credit issued to customers in the energy industry totaled $1.2 billion and $76.6 million, respectively, as of September 30, 2025, while unfunded commitments to extend credit and standby letters of credit issued to customers in the automobile dealership industry totaled $564.8 million and $20.0 million, respectively, as of September 30, 2025.

Foreign Loans. We have U.S. dollar denominated loans and commitments to borrowers in Mexico. The outstanding balance of these loans and the unfunded amounts available under these commitments werenot significant at September 30, 2025 or December 31, 2024.

Related Party Loans. In the ordinary course of business, we have granted loans to certain directors, executive officers, and their affiliates (collectively referred to as “related parties”). Such loans totaled $307.8 million at September 30, 2025 and $295.8 million at December 31, 2024.

Accrued Interest Receivable. Accrued interest receivable on loans totaled $91.8 million at September 30, 2025 and $86.8 million at December 31, 2024, and is included in accrued interest receivable and other assets in the accompanying consolidated balance sheets.

Federal Home Loan Bank Blanket Pledge. We have executed a blanket pledge and security agreement with the Federal Home Loan Bank (“FHLB”) under which certain qualifying loans are pledged as collateral for any outstanding borrowings under the agreement. Loans pledged under the blanket agreement totaled $19.3 billion at September 30, 2025 and $19.2 billion at December 31, 2024, thoughno FHLB borrowings were outstanding as of these dates.

Non-Accrual and Past Due Loans. Loans are considered past due if the required principal and interest payments have not been received as of the date such payments were due. Loans are placed on non-accrual status when, in management’s opinion, the borrower may be unable to meet payment obligations as they become due, as well as when required by regulatory provisions.

Non-accrual loans, segregated by class of loans, were as follows:

The following table presents non-accrual loans as of September 30, 2025, by class and year of origination.

In the table above, loans reported as 2025 originations as of September 30, 2025 were, for the most part, first originated in years prior to 2025 but were renewed in the current year. Had non-accrual loans performed in accordance with their original contract terms, we would have recognized additional interest income, net of tax, of approximately $929 thousand and $3.6 million for the three and nine months ended September 30, 2025, respectively, and approximately $1.5 million and $4.0 million for the three and nine months ended September 30, 2024, respectively.

An age analysis of past due loans (including both accruing and non-accruing loans), segregated by class of loans, as of September 30, 2025, was as follows:

Modifications to Borrowers Experiencing Financial Difficulty. From time to time, we may modify certain loans to borrowers who are experiencing financial difficulty. In some cases, these modifications may result in new loans. Loan modifications to borrowers experiencing financial difficulty may be in the form of a principal forgiveness, an interest rate reduction, an other-than-insignificant payment delay, or a term extension or a combination thereof, among other things. The period-end balance of loan modifications, segregated by type of modification, to borrowers experiencing financial difficulty during the nine months ended September 30, 2025 and 2024 are set forth in the table below, regardless of whether such modifications resulted in a new loan. There wereno commitments to lend additional funds to these borrowers at September 30, 2025.

The financial effects of the loan modifications made to borrowers experiencing financial difficulty were not significant during the nine months ended September 30, 2025 and 2024. The loan modifications reported in the table above did not significantly impact our determination of the allowance for credit losses on loans during their respective reporting periods.

Information as of September 30, 2025 and September 30, 2024, related to loans modified (by type of modification) in the preceding twelve months, respectively, whereby the borrower was experiencing financial difficulty at the time of modification is set forth in the following table.

Credit Quality Indicators. As part of the on-going monitoring of the credit quality of our loan portfolio, management tracks certain credit quality indicators including trends related to (i) the weighted-average risk grade of commercial loans, (ii) the level of classified commercial loans, (iii) the delinquency status of consumer loans, (iv) non-performing loans (see details above) and (v) the general economic conditions in the State of Texas.

We utilize a risk grading matrix to assign a risk grade to each of our commercial loans. Loans are graded on a scale of 1 to 14. A description of the general characteristics of the 14 risk grades is set forth in our 2024 Form 10-K. We monitor portfolio credit quality by the weighted-average risk grade of each class of commercial loan. Individual relationship managers, under the oversight of credit administration, review updated financial information for all pass grade loans to reassess the risk grade on at least an annual basis. When a loan has a risk grade of 9, it is still considered a pass grade loan; however, it is considered to be on management’s “watch list,” where a significant risk-modifying action is anticipated in the near term. When a loan has a risk grade of 10 or higher, a special assets officer monitors the loan on an on-going basis. The following table presents weighted-average risk grades for all commercial loans, by class and year of origination/renewal, as of September 30, 2025.

In the table above, certain loans are reported as 2025 originations and have risk grades of 11 or higher. These loans were, for the most part, first originated in various years prior to 2025 but were renewed in the current year.

The following tables present weighted average risk grades for all commercial loans by class as of December 31, 2024. Refer to our 2024 Form 10-K for details of these loans by year of origination/renewal.

Information about the payment status of consumer loans, segregated by portfolio segment and year of origination, as of September 30, 2025, was as follows:

Period-end balances for revolving loans that converted to term during the three and nine months ended September 30, 2025 and 2024 were as follows:

In assessing the general economic conditions in the State of Texas, management monitors and tracks the Texas Leading Index (“TLI”), which is produced by the Federal Reserve Bank of Dallas. The TLI, the components of which are more fully described in our 2024 Form 10-K, totaled 125.9 at August 31, 2025 (most recent date available) and 125.3 at December 31, 2024. A higher TLI value implies more favorable economic conditions.

Allowance For Credit Losses - Loans. The allowance for credit losses on loans is a contra-asset valuation account, calculated in accordance with ASC 326, that is deducted from the amortized cost basis of loans to present the net amount expected to be collected. The amount of the allowance represents management's best estimate of current expected credit losses on loans considering available information, from internal and external sources, relevant to assessing collectibility over the loans' contractual terms, adjusted for expected prepayments when appropriate. Credit loss expense related to loans reflects the totality of actions taken on all loans for a particular period including any necessary increases or decreases in the allowance related to changes in credit loss expectations associated with specific loans or pools of loans. Portions of the allowance may be allocated for specific credits; however, the entire allowance is available for any credit that, in management’s judgment, should be charged off. While management utilizes its best judgment and information available, the ultimate appropriateness of the allowance is dependent upon a variety of factors beyond our control, including the performance of our loan portfolio, the economy, changes in interest rates and the view of the regulatory authorities toward loan classifications. Our allowance methodology is more fully described in our 2024 Form 10-K.

The following table presents details of the allowance for credit losses on loans segregated by loan portfolio segment as of September 30, 2025 and December 31, 2024.

The following table details activity in the allowance for credit losses on loans by portfolio segment for the three and nine months ended September 30, 2025 and 2024. Allocation of a portion of the allowance to one category of loans does not preclude its availability to absorb losses in other categories.

The following table presents year-to-date gross charge-offs by year of origination as of September 30, 2025.

In the table above, $13.8 million of the consumer and other loan charge-offs reported as 2025 originations and $3.8 million of the total reported as 2024 originations were related to deposit overdrafts.

The following table presents loans that were evaluated for expected credit losses on an individual basis and the related specific allocations, by loan portfolio segment, as of September 30, 2025 and December 31, 2024.

Note 4 -Deposits

Deposits were as follows:

The table below presents additional information about our deposits. Public funds in excess of deposit insurance limits are included in the totals for deposits not covered by insurance; however, such deposits are generally fully collateralized by securities.

Note 5 -Off-Balance-Sheet Arrangements, Commitments, Guarantees and Contingencies

Financial Instruments with Off-Balance-Sheet Risk. In the normal course of business, we enter into various transactions, which, in accordance with generally accepted accounting principles are not included in our consolidated balance sheets. We enter into these transactions to meet the financing needs of our customers. As more fully discussed in our 2024 Form 10-K, these transactions include commitments to extend credit and standby letters of credit, which involve, to varying degrees, elements of credit risk and interest rate risk in excess of the amounts recognized in the consolidated balance sheets. We minimize our exposure to loss under these commitments by subjecting them to credit approval and monitoring procedures.

Financial instruments with off-balance-sheet risk were as follows:

Allowance For Credit Losses - Off-Balance-Sheet Credit Exposures. The allowance for credit losses on off-balance-sheet credit exposures is a liability account, calculated in accordance with ASC 326, representing expected credit losses over the contractual period for which we are exposed to credit risk resulting from a contractual obligation to extend credit. No allowance is recognized if we have the unconditional right to cancel the obligation. Off-balance-sheet credit exposures primarily consist of amounts available under outstanding lines of credit and letters of credit detailed in the table above. The amount of the allowance represents management's best estimate of expected credit losses on commitments expected to be funded over the contractual life of the commitment. Our allowance methodology is more fully described in our 2024 Form 10-K.

The following table details activity in the allowance for credit losses on off-balance-sheet credit exposures.

Lease Commitments. We lease certain office facilities and office equipment under operating leases. The components of total lease expense were as follows:

Right-of-use lease assets totaled $264.8 million at September 30, 2025 and $270.3 million at December 31, 2024, and are reported as a component of premises and equipment on our accompanying consolidated balance sheets. The related lease liabilities totaled $302.1 million at September 30, 2025 and $308.1 million at December 31, 2024, and are reported as a component of accrued interest payable and other liabilities in the accompanying consolidated balance sheets. Lease payments under operating leases that were applied to our operating lease liability totaled $9.4 million and $27.8 million during the three and nine months ended September 30, 2025, respectively, and $8.3 million and $25.3 million during the three and nine months ended September 30, 2024, respectively. There has beenno significant change in our expected future minimum lease payments since December 31, 2024. See the 2024 Form 10-K for information regarding these commitments.

Litigation. We are subject to various claims and legal actions that have arisen in the course of conducting business. Management does not expect the ultimate disposition of these matters to have a material adverse impact on our financial statements.

Note 6 -Capital and Regulatory Matters

Banks and bank holding companies are subject to various regulatory capital requirements administered by state and federal banking agencies. Capital adequacy guidelines and, additionally for banks, prompt corrective action regulations, involve quantitative measures of assets, liabilities, and certain off-balance-sheet items calculated under regulatory accounting practices. Capital amounts and classifications are also subject to qualitative judgments by regulators about components, risk weighting and other factors.

Cullen/Frost’s and Frost Bank’s Common Equity Tier 1 capital (“CET1”) includes common stock and related paid-in capital, net of treasury stock, and retained earnings. In connection with the adoption of the Basel III Capital Rules, we elected to opt-out of the requirement to include most components of accumulated other comprehensive income in CET1. We also elected to exclude the effects of credit loss accounting under CECL from CET1 for a five-year transitional period, as further discussed in our 2024 Form 10-K. This CECL transitional adjustment totaled $15.4 million at December 31, 2024, after which point the transitional period ended. CET1 is reduced by goodwill and other intangible assets, net of associated deferred tax liabilities. Frost Bank's CET1 is also reduced by its equity investment in its financial subsidiary, Frost Insurance Agency (“FIA”).

Tier 1 capital includes CET1 and additional Tier 1 capital. For Cullen/Frost, additional Tier 1 capital included $145.5 million of 4.450% non-cumulative perpetual preferred stock at September 30, 2025 and December 31, 2024, the details of which are further discussed below. Frost Bank didnot have any additional Tier 1 capital beyond CET1 at September 30, 2025 or December 31, 2024. Total capital includes Tier 1 capital and Tier 2 capital. Tier 2 capital for both Cullen/Frost and Frost Bank includes a permissible portion of the allowances for credit losses on securities, loans, and off-balance-sheet credit exposures. Tier 2 capital for Cullen/Frost also includes the permissible portion of qualified subordinated debt (which decreases 20.0% per year during the final five years of the term of the notes) totaling $20.0 million at September 30, 2025 and $40.0 million at December 31, 2024, and trust preferred securities totaling $120.0 million at both September 30, 2025 and December 31, 2024.

The following table presents actual and required capital ratios as of September 30, 2025 and December 31, 2024, for Cullen/Frost and Frost Bank under the Basel III Capital Rules. Capital levels required to be considered well-capitalized are based upon prompt corrective action regulations, as amended to reflect the changes under the Basel III Capital Rules. See the 2024 Form 10-K for a more detailed discussion of the Basel III Capital Rules.

(1)“Well-capitalized” minimum Common Equity Tier 1 to Risk-Weighted Assets and Leverage Ratio are not formally defined under applicable banking regulations for bank holding companies.

As of September 30, 2025, capital levels at Cullen/Frost and Frost Bank exceed all capital adequacy requirements under the Basel III Capital Rules. Based on the ratios presented above, capital levels as of September 30, 2025, at Cullen/Frost and Frost Bank exceed the minimum levels necessary to be considered “well-capitalized.”

Cullen/Frost and Frost Bank are subject to the regulatory capital requirements administered by the Federal Reserve Board and, for Frost Bank, the Federal Deposit Insurance Corporation (“FDIC”). Regulatory authorities can initiate certain mandatory actions if Cullen/Frost or Frost Bank fail to meet the minimum capital requirements, which could have a direct material effect on our financial statements. Management believes, as of September 30, 2025, that Cullen/Frost and Frost Bank meet all capital adequacy requirements to which they are subject.

Series B Preferred Stock. Outstanding preferred stock includes 150,000 shares, or $150.0 million in aggregate liquidation preference, of our 4.450% Non-Cumulative Perpetual Preferred Stock, Series B, par value $0.01 and liquidation preference $1,000 per share (“Series B Preferred Stock”). Each share of Series B Preferred Stock issued and outstanding is represented by 40 depositary shares, each representing a 1/40th ownership interest in a share of the Series B Preferred Stock (equivalent to a liquidation preference of $25 per share). The Series B Preferred Stock qualifies as Tier 1 capital for the purposes of the regulatory capital calculations. The net proceeds from the issuance and sale of the Series B Preferred Stock, after deducting $4.5 million of issuance costs including the underwriting discount and professional service fees, among other things, were approximately $145.5 million. Refer to our 2024 Form 10-K for additional details related to our Series B Preferred Stock.

Purchases of Equity Securities. From time to time, our board of directors has authorized stock repurchase plans. The purpose of such plans and the manner in which shares are repurchased is discussed in more detail in our 2024 Form 10-K. Most recently, on January 29, 2025, our board of directors authorized a $150.0 million stock repurchase program (the “2025 Repurchase Plan”), allowing us to repurchase shares of our common stock over aone-year period expiring on January 28, 2026. The 2025 Repurchase Plan was publicly announced in a current report on Form 8-K filed with the SEC on January 30, 2025.

Under the 2025 Repurchase Plan, we repurchased 549,228 shares at a total cost of $69.3 million (excluding applicable excise taxes) during the nine months ended September 30, 2025. We also repurchased 19,331 shares at a total cost of $2.7 million in connection with the vesting of certain share awards during the nine months ended September 30, 2025. Repurchases made in connection with the vesting of share awards are not associated with any publicly announced stock repurchase plan. Under a prior repurchase plan, we repurchased 489,862 shares at a total cost of $50.0 million (excluding applicable excise taxes) during the nine months ended September 30, 2024. We also repurchased 18,314 shares at a total cost of $2.1 million in connection with the vesting of certain share awards during the nine months ended September 30, 2024. Under the Basel III Capital Rules, Cullen/Frost may not repurchase or redeem any of its preferred stock or subordinated notes and, in some cases, its common stock without the prior approval of the Federal Reserve Board.

Dividend Restrictions. In the ordinary course of business, Cullen/Frost is dependent upon dividends from Frost Bank to provide funds for the payment of dividends to shareholders and to provide for other cash requirements, including to repurchase its common stock. Banking regulations may limit the amount of dividends that may be paid. Approval by regulatory authorities is required if the effect of dividends declared would cause the regulatory capital of Frost Bank to fall below specified minimum levels. Approval is also required if dividends declared exceed the net profits for that year combined with the retained net profits for the preceding two years. Under the foregoing dividend restrictions and while maintaining its “well-capitalized” status, at September 30, 2025, Frost Bank could pay aggregate dividends of up to $923.3 million to Cullen/Frost without prior regulatory approval.

Under the terms of the junior subordinated deferrable interest debentures that Cullen/Frost has issued to Cullen/Frost Capital Trust II, Cullen/Frost has the right at any time during the term of the debentures to defer the payment of interest at any time or from time to time for an extension period not exceeding 20 consecutive quarterly periods with respect to each extension period. In the event that we have elected to defer interest on the debentures, we may not, with certain exceptions, declare or pay any dividends or distributions on our capital stock or purchase or acquire any of our capital stock.

Under the terms of the Series B Preferred Stock, in the event that we do not declare and pay dividends on the Series B Preferred Stock for the most recent dividend period, we may not, with certain exceptions, declare or pay dividends on, or purchase, redeem or otherwise acquire, shares of our common stock or any of our securities that rank junior to the Series B Preferred Stock.

Note 7 -Derivative Financial Instruments

The fair value of derivative positions outstanding is included in accrued interest receivable and other assets and accrued interest payable and other liabilities in the accompanying consolidated balance sheets and in the net change in each of these financial statement line items in the accompanying consolidated statements of cash flows.

Interest Rate Derivatives. We utilize interest rate swaps, caps and floors to mitigate exposure to interest rate risk and to facilitate the needs of our customers. Our objectives for utilizing our currently outstanding derivative positions are described below:

We have entered into certain interest rate derivative contracts that are not designated as hedging instruments to accommodate the business needs of our customers. These derivative contracts relate to transactions in which we enter into an interest rate swap, cap and/or floor with a customer while at the same time entering into an offsetting interest rate swap, cap and/or floor with a third-party financial institution. In connection with each swap transaction, we agree to pay interest to the customer on a notional amount at a variable interest 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. The transaction allows our customer to effectively convert a variable rate loan to a fixed rate. Because we act as an intermediary for our customers, changes in the fair value of the underlying derivative contracts largely offset each other and do not significantly impact our results of operations.

The notional amounts and estimated fair values of interest rate derivative contracts outstanding are presented in the following table. The fair values of these contracts are estimated utilizing internal valuation methods with observable market data inputs, or as determined by the Chicago Mercantile Exchange (“CME”) for centrally cleared derivative contracts. CME rules legally characterize variation margin payments for centrally cleared derivatives as settlements of the derivatives' exposure rather than collateral. As a result, the variation margin payment and the related derivative instruments are considered a single unit of account for accounting and financial reporting purposes. Variation margin, as determined by the CME, is settled daily. As a result, derivative contracts that clear through the CME have an estimated fair value ofzero.

The weighted-average rates paid and received for interest rate swaps outstanding at September 30, 2025, were as follows:

The weighted-average strike rate for outstanding interest rate caps was 3.80% at September 30, 2025.

Commodity Derivatives. We enter into certain commodity derivative contracts that are not designated as hedging instruments to accommodate the business needs of our customers. Upon the origination of a commodity derivative contract with a customer, we simultaneously enter into an offsetting contract with a third-party financial institution to mitigate our exposure to fluctuations in commodity prices. Because we act as an intermediary for our customers, changes in the fair value of the underlying derivative contracts largely offset each other and do not significantly impact our results of operations.

The notional amounts and estimated fair values of non-hedging commodity derivative contracts outstanding are presented in the following table. The fair values of these contracts are estimated utilizing internal valuation methods with observable market data inputs.

Foreign Currency Derivatives. We enter into foreign currency derivative contracts that are not designated as hedging instruments to accommodate the business needs of our customers and to mitigate our exposure to foreign currency. Upon the origination of a foreign currency derivative contract with a customer, we simultaneously enter into an offsetting contract with a third-party financial institution to mitigate our exposure to fluctuations in foreign currency exchange rates. Because we act as an intermediary for our customers, changes in the fair value of the underlying derivative contracts largely offset each other and do not significantly impact our results of operations. We also utilize foreign currency derivative contracts that are not designated as hedging instruments to mitigate the economic effect of fluctuations in foreign currency exchange rates on foreign currency holdings and certain short-term, non-U.S. dollar denominated loans. The notional amounts and fair values of non-hedging foreign currency derivative contracts are presented in the following table. The fair values of these contracts are estimated utilizing internal valuation methods with observable market data inputs.

Gains, Losses and Derivative Cash Flows. For non-hedging derivative instruments, gains and losses due to changes in fair value and all cash flows are included in other non-interest income and other non-interest expense as presented in the table below.

Counterparty Credit Risk. At September 30, 2025, our credit exposure relating to outstanding derivative contracts with bank customers was approximately $22.6 million. This credit exposure is partly mitigated as transactions with customers are generally secured by the collateral, if any, securing the underlying transaction being hedged. At September 30, 2025, after consideration of collateral pledged, we had $4.0 million credit exposure relating to outstanding derivative contracts with upstream financial institution counterparties. Collateral positions are generally cleared on the next business day. Collateral levels for upstream financial institution counterparties are monitored and adjusted, as necessary. See Note 8 – Balance Sheet Offsetting and Repurchase Agreements for additional information regarding our credit exposure with upstream financial institution counterparties. At September 30, 2025, we had $12.5 million in cash collateral related to derivative contracts on deposit with other financial institution counterparties.

Note 8 -Balance Sheet Offsetting and Repurchase Agreements

Balance Sheet Offsetting. Certain financial instruments, including resell and repurchase agreements and derivatives, may be eligible for offset in the consolidated balance sheet and/or subject to master netting arrangements or similar agreements. Our derivative transactions with upstream financial institution counterparties are generally executed under International Swaps and Derivative Association (“ISDA”) master agreements which include “right of set-off” provisions. In such cases there is generally a legally enforceable right to offset recognized amounts and there may be an intention to settle such amounts on a net basis. Nonetheless, we do not generally offset such financial instruments for financial reporting purposes.

Information about financial instruments that are eligible for offset in the consolidated balance sheet as of September 30, 2025, is presented in the following tables.

Information about financial instruments that are eligible for offset in the consolidated balance sheet as of December 31, 2024, is presented in the following tables.

Repurchase Agreements. We utilize securities sold under agreements to repurchase to facilitate the needs of our customers and to facilitate secured short-term funding needs. Securities sold under agreements to repurchase are stated at the amount of cash received in connection with the transaction. We monitor collateral levels on a continuous basis. We may be required to provide additional collateral based on the fair value of the underlying securities. Securities pledged as collateral under repurchase agreements are maintained with our safekeeping agents.

The remaining contractual maturity of repurchase agreements in the consolidated balance sheets as of September 30, 2025 and December 31, 2024, is presented in the following tables.

Note 9 -Stock-Based Compensation

A combined summary of activity in our active stock plans is presented in the table below. Performance stock units outstanding are presented assuming attainment of the maximum payout rate as set forth by the performance criteria. As of September 30, 2025, there were 2,353,029 shares remaining available for grant for future stock-based compensation awards.

Shares issued in connection with stock compensation awards are issued from available treasury shares. If no treasury shares are available, new shares are issued from available authorized shares. Shares issued in connection with stock compensation awards along with other related information were as follows:

Stock-based compensation expense is recognized ratably over the requisite service period for all awards. All stock option awards currently outstanding are fully vested and the service period for such awards generally matched the vesting period in most cases. The service period for non-vested stock units does not extend past the date the participant reaches 65 years of age. Deferred stock units granted to non-employee directors generally have immediate vesting and the related expense is fully recognized on the date of grant. For performance stock units, the service period generally matches the three-year performance period specified by the award, however, the service period does not extend past the date the participant reaches 65 years of age. Expense recognized each period is dependent upon our estimate of the number of shares that will ultimately be issued.

Stock-based compensation expense or benefit and the related income tax benefit is presented in the following table. The service period for performance stock units granted each year begins on January 1 of the following year.

Unrecognized stock-based compensation expense at September 30, 2025 is presented in the table below. Unrecognized stock-based compensation expense related to performance stock units is presented assuming attainment of the maximum payout rate as set forth by the performance criteria.

Note 10 -Earnings Per Common Share

Earnings per common share is computed using the two-class method as more fully described in our 2024 Form 10-K. The following table presents a reconciliation of net income available to common shareholders, net earnings allocated to common stock and the number of shares used in the calculation of basic and diluted earnings per common share.

Note 11 -Defined Benefit Plans

The components of the combined net periodic expense (benefit) for our defined benefit pension plans are presented in the table below.

Our non-qualified defined benefit pension plan is not funded. No contributions to the qualified defined benefit pension plan were made during the nine months ended September 30, 2025. We donot expect to make any contributions to the qualified defined benefit plan during the remainder of 2025.

Note 12 -Income Taxes

Income tax expense was as follows:

We had a net deferred tax asset totaling $285.1 million at September 30, 2025 and $375.2 million at December 31, 2024. No valuation allowance for deferred tax assets was recorded as of those dates as management believes it is more likely than not that all of the deferred tax assets will be realized against deferred tax liabilities and projected future taxable income.

The effective income tax rates differed from the U.S. statutory federal income tax rates of 21% during the comparable periods primarily due to the effect of tax-exempt income from securities, loans and life insurance policies and the income tax effects associated with stock-based compensation, among other things. There wereno unrecognized tax benefits during any of the reported periods. Interest and/or penalties related to income taxes are reported as a component of income tax expense. Such amounts were not significant during the reported periods.

We file income tax returns in the U.S. federal jurisdiction. We are no longer subject to U.S. federal income tax examinations by tax authorities for years before 2021.

Note 13 -Other Comprehensive Income (Loss)

The before and after-tax amounts allocated to each component of other comprehensive income (loss) are presented in the following table. Reclassification adjustments related to securities available for sale are included in net gain (loss) on securities transactions in the accompanying consolidated statements of income. Reclassification adjustments related to defined-benefit post-retirement benefit plans are included in the computation of net periodic pension expense (see Note 11 – Defined Benefit Plans).

Activity in accumulated other comprehensive income (loss), net of tax, was as follows:

Note 14 –Operating Segments

We are managed under a matrix organizational structure whereby ourtwo primary operating segments, Banking and Frost Wealth Advisors, overlap a regional reporting structure. The regions are primarily based upon geographic location and include Austin, Dallas, Fort Worth, Gulf Coast (which includes Corpus Christi and the Rio Grande Valley), Houston, Permian Basin, San Antonio and Statewide. We are primarily managed based on the line of business structure. In that regard, all regions have the same lines of business, which have the same product and service offerings, have similar types and classes of customers and utilize similar service delivery methods. Pricing guidelines for products and services are the same across all regions. The regional reporting structure is primarily a means to scale the lines of business to provide a local, community focus for customer relations and business development. See our 2024 Form 10-K for additional information about our operating segments and related accounting policies.

Our chief executive officer is our chief operating decision maker. We use a match-funded transfer pricing process to allocate costs, capital and resources to each operating segment. The process helps us to (i) identify the cost or opportunity value of funds within each business segment, (ii) measure the profitability of a particular business segment by relating appropriate costs to revenues, (iii) evaluate each business segment in a manner consistent with its economic impact on consolidated earnings, and (iv) enhance asset and liability pricing decisions. Our chief executive officer reviews actual net income versus budgeted net income to assess segment performance on a monthly basis and to make decisions about allocating capital and personnel to the segments. Financial results by operating segment, including significant expense categories provided to the chief operating decision maker, are detailed below.

Note 15 –Fair Value Measurements

The fair value of an asset or liability is the price that would be received to sell that asset or paid to transfer that liability in an orderly transaction occurring in the principal market (or most advantageous market in the absence of a principal market) for such asset or liability. In estimating fair value, we utilize valuation techniques that are consistent with the market approach, the income approach and/or the cost approach. Such valuation techniques are consistently applied. Inputs to valuation techniques include the assumptions that market participants would use in pricing an asset or liability. ASC Topic 820 establishes a three-level fair value hierarchy for valuation inputs that gives the highest priority to quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. See our 2024 Form 10-K for additional information regarding the fair value hierarchy and a description of our valuation techniques.

Financial Assets and Financial Liabilities. The tables below summarize financial assets and financial liabilities measured at fair value on a recurring basis as of September 30, 2025 and December 31, 2024, segregated by the level of the valuation inputs within the fair value hierarchy of ASC Topic 820 utilized to measure fair value.

Certain financial assets and financial liabilities are measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments in certain circumstances. Financial assets measured at fair value on a non-recurring basis during the reported periods include certain collateral dependent loans reported at the fair value of the underlying collateral if repayment is expected solely from the collateral.

The following table presents collateral dependent loans that were remeasured and reported at fair value through a specific allocation of the allowance for credit losses on loans based upon the fair value of the underlying collateral during the reported periods.

Non-Financial Assets and Non-Financial Liabilities. We donot have any non-financial assets or non-financial liabilities measured at fair value on a recurring basis. From time to time, non-financial assets measured at fair value on a non-recurring basis may include certain foreclosed assets which, upon initial recognition, were remeasured and reported at fair value through a charge-off to the allowance for loan losses and certain foreclosed assets which, subsequent to their initial recognition, were remeasured at fair value through a write-down included in other non-interest expense.

The following table presents foreclosed assets that were remeasured and reported at fair value during the reported periods:

Financial Instruments Reported at Amortized Cost. The estimated fair values of financial instruments that are reported at amortized cost in our consolidated balance sheets, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value, were as follows:

Under ASC Topic 825, entities may choose to measure eligible financial instruments at fair value at specified election dates. The fair value measurement option (i) may be applied instrument by instrument, with certain exceptions, (ii) is generally irrevocable and (iii) is applied only to entire instruments and not to portions of instruments. Unrealized gains and losses on items for which the fair value measurement option has been elected must be reported in earnings at each subsequent reporting date. During the reported periods, we hadno financial instruments measured at fair value under the fair value measurement option.

Note 16 -Accounting Standards Updates

Information about certain recently issued accounting standards updates is presented below. Also refer to Note 19 - Accounting Standards Updates in our 2024 Form 10-K for additional information related to previously issued accounting standards updates.

ASU No. 2023-07,“Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures.”ASU 2023-07 expands segment disclosure requirements for public entities to require disclosure of significant segment expenses and other segment items on an annual and interim basis and to provide in interim periods all disclosures about a reportable segment’s profit or loss and assets that are currently required annually. As noted in our 2024 Form 10-K, we adopted ASU 2023-07 for our annual financial statements in 2024. ASU 2023-07 became effective for interim periods in 2025. See Note 14 - Operating Segments.

ASU No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures.”ASU 2023-09 requires public business entities to disclose in their rate reconciliation table additional categories of information about federal, state and foreign income taxes and to provide more details about the reconciling items in some categories if items meet a quantitative threshold. ASU 2023-09 also requires all entities to disclose income taxes paid, net of refunds, disaggregated by federal, state and foreign taxes for annual periods and to disaggregate the information by jurisdiction based on a quantitative threshold, among other things. ASU 2023-09 will be effective for our annual financial statements for the year ended December 31, 2025.

ASU No. 2024-03, “Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses.”ASU 2024-03 requires disaggregated disclosure of income statement expenses for public business entities. ASU 2024-03 requires new financial statement disclosures in tabular format, disaggregating information about prescribed categories underlying any relevant income statement expense caption. The prescribed categories include, among other things, employee compensation, depreciation, and intangible asset amortization. Additionally, entities must disclose the total amount of selling expenses and, in annual reporting periods, an entity’s definition of selling expenses. ASU 2024-03 is effective for us, on a prospective basis, for annual periods beginning in 2027, and interim periods within fiscal years beginning in 2028, though early adoption and retrospective application is permitted. ASU 2024-03 is not expected to have a significant impact on our financial statements.

ASU No. 2025-05,“Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets.”ASU 2025-05 provides all entities, when developing reasonable and supportable forecasts as part of estimating expected credit losses on current accounts receivable and/or current contract assets arising from transactions under ASC Topic 606 - Revenue from Contracts with Customers, a practical expedient whereby entities can assume that current conditions as of the balance sheet date do not change for the remaining life of the asset. ASU 2025-05 will be effective in 2026 and is not expected to have a significant impact on our financial statements.

ASU No. 2025-06,“Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software.”ASU 2025-06 simplifies and modernizes the accounting for internal-use software by removing prescriptive project stage guidance and introducing a new capitalization threshold. Under the revised standard, software development costs are capitalized when management authorizes and commits funding for the project and it is probable the software will be completed and used as intended. ASU 2025-06 will be effective in 2028 and is not expected to have a significant impact on our financial statements.