UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-Q

For the quarterly period ended March 31, 2026

or

For the transition period from to

Commission file number 000-03683

Trustmark Corporation

(Exact name of registrant as specified in its charter)

(601) 208-5111

(Registrant’s telephone number, including area code)

Securities registered Pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

As of April 30, 2026, there were 58,605,547 shares outstanding of the registrant’s common stock (no par value).

Forward-Looking Statements

Certain statements contained in this Quarterly Report on Form 10-Q constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. You can identify forward-looking statements by words such as “may,” “hope,” “will,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “project,” “potential,” “seek,” “continue,” “could,” “would,” “future” or the negative of those terms or other words of similar meaning. You should read statements that contain these words carefully because they discuss our future expectations or state other “forward-looking” information. These forward-looking statements include, but are not limited to, statements relating to anticipated future operating and financial performance measures, including net interest margin, credit quality, business initiatives, growth opportunities and growth rates, among other things, and encompass any estimate, prediction, expectation, projection, opinion, anticipation, outlook or statement of belief included therein as well as the management assumptions underlying these forward-looking statements. You should be aware that the occurrence of the events described under the caption “Risk Factors” in Trustmark’s filings with the Securities and Exchange Commission (SEC) could have an adverse effect on our business, results of operations or financial condition. Should one or more of these risks materialize, or should any such underlying assumptions prove to be significantly different, actual results may vary significantly from those anticipated, estimated, projected or expected.

Risks that could cause actual results to differ materially from current expectations of Management include, but are not limited to, actions by the Board of Governors of the Federal Reserve System (FRB) that impact the level of market interest rates, local, state, national and international economic and market conditions, conditions in the housing and real estate markets in the regions in which Trustmark operates, conditions and changes, including volatility, in the credit and financial markets, changes in the level of nonperforming assets and charge-offs, an increase in unemployment levels, a slowdown in economic growth, changes in our ability to measure the fair value of assets in our portfolio, changes in the level and/or volatility of market interest rates, the impacts related to or resulting from bank failures and other economic and industry volatility, including potential increased regulatory requirements, the demand for the products and services we offer, potential unexpected adverse outcomes in pending litigation matters, our ability to attract and retain noninterest-bearing deposits and other low-cost funds, competition in loan and deposit pricing, as well as the entry of new competitors into our markets through de novo expansion and acquisitions, changes in accounting standards and practices, including changes in the interpretation of existing standards, that affect our consolidated financial statements, changes in consumer spending, borrowings and savings habits, technological changes, changes in the financial performance or condition of our borrowers, greater than expected costs or difficulties related to the integration of acquisitions or new products and lines of business, cyber-attacks and other breaches which could affect our information system security, natural disasters, environmental disasters, pandemics or other health crises, acts of war or terrorism, potential market or regulatory effects of the current United States presidential administration’s policies, changes to the credit rating of U.S. Government securities and other risks described in our filings with the SEC.

Although we believe that the expectations reflected in such forward-looking statements are reasonable, we can give no assurance that such expectations will prove to be correct. Except as required by law, we undertake no obligation to update or revise any of this information, whether as the result of new information, future events or developments or otherwise.

PART I. FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

Trustmark Corporation and Subsidiaries

Consolidated Balance Sheets

($ in thousands)