SEC Form FWP filed by Trustmark Corporation

Fixed Income Investor Presentation November 2025

Safe Harbor Statement and Disclaimers Certain statements contained in this presentation 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. This presentation is not an offer to sell securities and Trustmark Corporation (Trustmark) is not soliciting an offer to buy securities in any jurisdiction where such offer or sale is not permitted. Neither the SEC nor any state securities commission has approved or disapproved of the securities of Trustmark or passed upon the accuracy or adequacy of this presentation. Any representation to the contrary is a criminal offence. Except as otherwise indicated, this presentation speaks as of the date hereof. Trustmark has filed a shelf registration statement (including a base prospectus) and a preliminary prospectus supplement with the SEC for the offering to which this presentation relates. Before you invest, you should read the prospectus in that registration statement, the preliminary prospectus supplement and other documents Trustmark has filed with the SEC for more complete information about Trustmark and this offering. You may access these documents for free by visiting EDGAR on the SEC’s website at www.sec.gov. Alternatively, Trustmark, any underwriter or any dealer participating in the offering will arrange to send you the prospectus and the related preliminary prospectus supplement if you request it by contacting Keefe, Bruyette & Woods, A Stifel Company, toll-free at 1-800-966-1599 or by email at [email protected], or Goldman Sachs & Co. LLC, toll-free at 1-866-471-2526 or by email at [email protected]. This presentation includes statistical and other industry and market data that we obtained from government reports and other third-party sources. Our internal data, estimates, and forecasts are based on information obtained from government reports, trade, and business organizations and other contacts in the markets in which we operate and our management’s understanding of industry conditions. Although we believe that this information (including the industry publications and third-party research, surveys, and studies) is accurate and reliable, we have not independently verified such information. In addition, estimates, forecasts, and assumptions are necessarily subject to a high degree of uncertainty and risk due to a variety of factors. Finally, forward-looking information obtained from these sources is subject to the same qualifications and the additional uncertainties regarding the other forward-looking statements in this presentation. Numbers contained in this presentation for the quarter ended September 30, 2025 and for other quarterly periods are unaudited. Additionally, all figures presented as year-to-date and for periods that represent a full fiscal year ended December 31 represent unaudited results. As a result, subsequent information may cause a change in certain accounting estimates and other financial information, including Trustmark’s allowance for credit losses, fair values, and income taxes. This presentation includes financial information in its analysis of Trustmark’s performance that is not in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The reconciliations of these measures to their most directly comparable GAAP equivalents are provided in the Appendix to this presentation. These disclosures should not be viewed as a substitute for operating results determined in accordance with GAAP, nor are they necessarily comparable to non-GAAP performance measures that may be presented by other companies.2

3 Table of Contents Offering Summary 4 Company Overview 5-7 Q3 ’25 Results 8 Historical Growth 9-10 Capital Position 11-12 Net Interest Income 13 Deposit Portfolio 14 Loan Portfolio 15-19 Asset Quality 20-21 Liquidity Profile 22-23 Noninterest Income & Expense 24-25 Appendix 26-33

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. Offering Summary * An explanation of the significance of ratings may be obtained from the rating agency. Generally, rating agencies base their ratings on such material and information, and such of their own investigations, studies and assumptions, as they deem appropriate. The rating of the subordinated notes should be evaluated independently from similar ratings of other securities. A credit rating of a security is not a recommendation to buy, sell or hold securities and may be subject to review, revision, suspension, reduction or withdrawal at any time by the assigning rating agency. No report of any rating agency is incorporated by reference herein.Issuer: Trustmark Corporation Security Offered: Fixed-to-Floating Subordinated Notes due 2035 Offering Size: $125 Million Expected Security Rating: BBB- (Stable) S&P* / BBB- (Stable) Fitch Ratings* Format: SEC Registered Term: 10 Years Call: 5 Years Use of Proceeds: Repayment of TRMK’s existing 3.625% subordinated notes due 2035, together with cash in hand, if needed, and for general corporate purposes Joint Bookrunning Managers: Keefe Bruyette & Woods, A Stifel Company Goldman Sachs & Co. LLC

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. Today’s Presenters v Duane Dewey President, Chief Executive Officer Trustmark Corporation Trustmark Bank Mr. Dewey, with 40 years of banking experience, was named President and CEO in January 2021. Mr. Dewey joined Trustmark in 2003 as President of Wealth Management and assumed additional responsibilities for Commercial Real Estate, Institutional Banking, Corporate Banking, and Treasury Management. In 2019, Mr. Dewey was named Chief Operating Officer and, in 2020, became President and COO and joined the Board of Directors. Prior to joining Trustmark, Mr. Dewey served as Managing Director of Wealth Management at Provident Bank in Cincinnati, OH, and at Bank of America in Corporate Banking in Dallas, TX and in Private Banking in Washington, DC. Tom Owens Treasurer, Principal Financial Officer Trustmark Corporation Executive VP, Chief Financial Officer Trustmark Bank Mr. Owens was named Chief Financial Officer effective March 2021. Joined Trustmark in 2013, initially serving as Executive Vice President and Bank Treasurer. Prior experience includes over 25 years in financial leadership roles at other leading banking organizations, including KeyBank and Wachovia. Barry Harvey Executive VP, Chief Credit and Operations Officer Trustmark Bank Mr. Harvey serves as Executive Vice President and Chief Credit and Operations Officer at Trustmark, having joined the company in 1999. Directs all credit, IT, and operational activities and provides strategic guidance for the bank’s lending and deposit functions. Prior experience includes 38 years in the financial services industry with expertise in portfolio management and credit analysis. Tom Chambers Principal Accounting Officer Trustmark Corporation Executive VP, Chief Accounting Officer Trustmark Bank Mr. Chambers serves as Executive Vice President and Chief Accounting Officer for Trustmark Bank and serves as the Principal Accounting Officer for Trustmark Corporation, having joined the company in 2002. As Chief Accounting Officer, Mr. Chambers oversees Accounting, which includes Securities Exchange Commission and Regulatory external reporting, Corporate Taxes, Accounts Payable, and Strategic Sourcing. Mr. Chambers previously served as Director of Finance of Mississippi for BellSouth Mobility. Granville Tate, Jr. Secretary Trustmark Corporation Executive VP, Chief Administrative Officer, Secretary Trustmark Bank Mr. Tate, Jr. was named Chief Administrative Officer effective January 2021. Joined Trustmark in 2015, overseeing the Corporate Governance, Risk Management, Corporate Security, Facilities, Asset Review and Legal areas of the organization. Also serves as Secretary of Trustmark Corporation and Trustmark Bank. Prior experience includes over 30 years in private legal practice, with a focus on Banking, Corporate, and Finance Law. Joey Rein Assistant Secretary Trustmark Corporation Executive VP, Director of Corporate Strategy Trustmark Bank Mr. Rein serves as Director of Corporate Strategy, responsible for M&A, strategic planning, and investor relations, having joined the company in 1998. Also serves as Assistant Secretary of Trustmark Corporation and Trustmark Bank, managing corporate governance duties. Prior experience in Corporate Planning and Development at Deposit Guaranty Corp.

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. Trustmark Corporation Trustmark is a diversified financial services company headquartered in Jackson, MS, providing banking and financial solutions through offices in AL, FL, GA, MS, TN and TX Our vision is to be a premier financial services provider in our marketplace. Our mission is to achieve outstanding customer satisfaction by providing banking and wealth management solutions through superior sales and service, utilizing excellent people, teamwork, and diversity, while meeting our corporate financial goals. Who We Are Strategic Priorities to Enhance Shareholder Value Pursue efficiency opportunities through adoption of technology, redesign of workflows and workforce structure Focus on profitable growth to increase EPS, enhance scale, benefit from favorable demographic trends in growth markets, and increase penetration across lines of business Invest in technology solutions and data analytics to drive customer engagement, inform sales practices, and aid in the development and enhancement of product or service offerings Prioritize risk management throughout the organization by incorporating industry leading practices to comply with all applicable regulatory requirements Adopt a mindset that embraces growth, innovation and efficiency while maintaining core values and sound risk management practices Our Footprint LPO6

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. Our Company Franchise Overview TRMK (167) LPO (1) FL AL TN MS LA TX Houston Jackson Birmingham Memphis Tallahassee Atlanta GA 10.3% Leverage Ratio 9.6% TCE / TA* Company Highlights $13.5B Gross Loans HFI $18.8B Total Assets $10.1B Wealth AUM(1) $15.6B Total Deposits 14.3% TRBC Ratio #2 Mississippi Market Share(2) 1889 Year Founded Outstanding CRA Rating(3) BBB S&P Issuer Rating BBB Fitch Issuer Rating Profitability Capital & Asset Quality Ratings 0.49% NPAs / Assets 0.13% NCOs / Avg Loans 60% C&D / TRBC(4) 249% CRE / TRBC(4) 11.9% CET1 Ratio 1.21% ROAA 12.84% ROATCE* 1.84% Cost of Deposits 20% Fee Income / Total Revenue * A reconciliation of this non-GAAP measure is set forth in appendix Note: Unless otherwise stated, financial data as of or for the 3 months ended 9/30/25 Note: TRMK’s Loan Production Office is responsible for the nationwide equipment finance business (1)AUM as of 9/30/2025 per TRMK 10-Q filing (2)Deposit market share data as of 6/30/25 (3)TRMK formally upgraded to “outstanding” status in February 2025 (4)Financial data per bank level regulatory filings; CRE ratio excludes owner-occupied CRE per regulatory definition Company Info Balance Sheet7

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. Financial Highlights – Third Quarter 2025 Loans held for investment (HFI) increased $83.4 million, or 0.6%, linked-quarter, and a $448.0 million, or 3.4%, increase year-over-year Total deposits increased $515.1 million, or 3.4%, linked-quarter, and $390.0 million, or 2.6%, from the prior year; cost of total deposits increased 4 basis points to 1.84% At September 30, 2025 Total Assets $18.8 billion Loans (HFI) $13.5 billion Total Deposits $15.6 billion Banking Centers 167

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. Tangible Book Value Per Share* Enhanced Financial Positioning NIM—FTE Total Deposits Loans HFI ($ in billions) ($ in billions) * A reconciliation of this non-GAAP measure is set forth in appendix9 3.17% 3.32% 3.51% 3.80% 2022 2023 2024 9/30/2025 YTD $12.2 $13.0 $13.1 $13.5 2022 2023 2024 9/30/2025 YTD $18.98 $21.73 $26.68 $29.60 2022 2023 2024 9/30/2025 YTD $14.4 $15.6 $15.1 $15.6 2022 2023 2024 9/30/2025 YTD

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. $60,918 $153,290 $45,210 $166,261 $136,481 $159,220 $186,335 2022 2023 2024 9/30/2025 YTD Net Income from Continuing Operations (GAAP) (in thousands) Net Income from Adjusted Continuing Operations* (Non-GAAP) (in thousands) $0.99 $2.50 $0.74 $2.74 $2.22 $2.60 $3.04 2022 2023 2024 9/30/2025 YTD Diluted EPS from Continuing Operations (GAAP) (in thousands) Diluted EPS from Adjusted Continuing Operations* (Non-GAAP) 0.35% 0.82% 0.24% 1.21% 0.78% 0.86% 1.01% 2022 2023 2024 9/30/2025 YTD ROAA from Continuing Operations (GAAP) ROAA from Adjusted Continuing Operations* (Non-GAAP) Consistent Growth in Profitability Net Income Available to Shareholders Diluted EPS ROAA ROATCE* * A reconciliation of this non-GAAP measure is set forth in appendix Note: 2024 GAAP metrics include one-time losses related to securities repositioning completed in Q2 202410 4.86% 12.43% 3.04% 13.03% 10.78% 12.95% 12.71% 2022 2023 2024 9/30/2025 YTD ROATCE from Continuing Operations (GAAP) ROATCE from Adjusted Continuing Operations* (Non-GAAP)

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. 1 Current Capital Position Regulatory Capital as of September 30, 2025 Capital Highlights Common Equity Tier 1 $1,813 Trust Preferred $60 ACL $191 Subordinated Notes $124 Tier 1 $1,873 Tier 2 $315 $ in millions Subordinated Notes Approaching Call Phase: The $125.0 million subordinated notes remain outstanding. They will begin to phase out of Tier 2 capital on a 20% annual basis starting December 1, 2025. Legacy Tier 1 Capital: The company continues to utilize $60.0 million in trust preferred securities as Tier 1 capital under regulatory grandfathering provisions. 14.3% Total Capital Ratio 11.9% CET1 Ratio 12.3% Tier 1 Ratio 10.3% Leverage Ratio 9.6% TCE / TA* * A reconciliation of this non-GAAP measure is set forth in appendix11

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. 9.6% 9.3% TRMK Peer Median 11.6% 11.4% TRMK Peer Median 9.5% 8.9% TRMK Peer Median 11.9% 11.6% TRMK Peer Median Strong Capital Position Relative to Peers Source: S&P Global Market Intelligence * A reconciliation of this non-GAAP measure is set forth in appendix Note: Financial data as of 9/30/2025 Note: Peers include major-exchange traded banks headquartered in the Southeast with assets between $10bn and $50bn; Excludes merger targets and mutual holding companies Note: Assumes a tax rate of 21.0% for peer after-tax HTM losses; Assumes a tax rate of 25.0% for TRMK after-tax HTM losses Tangible Common Equity / Tangible Assets* Common Equity Tier 1 Ratio* Common Equity Tier 1, including AOCI & HTM* TCE/TA, including After-Tax HTM Losses* 12

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. $158 $158 $155 $161 $165 Q3-24 Q4-24 Q1-25 Q2-25 Q3-25 Net Interest Income – FTE ($ in millions) Net Interest Income Income Statement Highlights – Net Interest Income Net interest income (FTE) totaled $165.2 million in the third quarter, resulting in a net interest margin of 3.83%, up 2 basis points from the prior quarter Securities yield during Q3-25 was 3.50%, up 4 basis points linked-quarter and an increase of 6 basis points year-over-year 3.81%0.09%-0.03%-0.04%3.83%Q2-25 NIMQ3-25 NIM Asset Rate/Volume Liability Rate/Volume Net Interest Margin Yields and Costs(1) # of Days in Qtr 13 (1)Loan Yield includes LHFI & LHFS 3.69% 3.76% 3.75% 3.81% 3.83% 3.44% 3.41% 3.46% 3.46% 3.50% 2.94% 2.61% 2.43% 2.42% 2.44% Q3-24 Q4-24 Q1-25 Q2-25 Q3-25 Loan Yield NIM Securities Yield Cost of IBL 6.55% 6.32% 6.15% 6.19% 6.21%

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. 20.6% 20.3% 20.4% 20.7% 21.2% 29.9% 31.2% 30.6% 29.8% 28.8% 27.5% 27.3% 27.9% 27.1% 27.6% 21.9% 21.1% 21.2% 22.4% 22.3% 93.9% 93.8% 93.8% 93.3% 93.2% 2024Q3 2024Q4 2025Q1 2025Q2 2025Q3 Demand/Non-Interest Bearing NOW & Other Trans. Accounts MMDA & Other Savings Time $15.2 $15.1 $15.1 $15.1 $15.6 2.22% 1.98% 1.83% 1.80% 1.84% 2.49% 2.31% 2.15% 2.12% 2.15% 2024Q3 2024Q4 2025Q1 2025Q2 2025Q3 TRMK Peer Median (3) Diverse, Low Cost & Core Deposit Base Source: S&P Global Market Intelligence Note: Financial data as of or for the respective period and 9/30/25, as applicable (1) Percentages may not sum to 100% due to rounding (2) Core deposits exclude jumbo time deposits (>$250k) (3) Peers include major-exchange traded banks headquartered in the Southeast with assets between $10bn and $50bn; Excludes merger targets and mutual holding companies Deposit Composition Over Time(1) Cost of Deposits Relative to Peers Granular Deposit Base Core Deposits(2) (%) Average deposit account size of $34k Top 20 commercial depositors represent 2.9% of total deposits Average retail deposit size of $22k Top 20 retail depositors represent 1.7% of total deposits Average commercial deposit size of $78k Total Deposits ($bn) ($ in billions) 14

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. Prime, 9% Variable (<= 1-month), 42% Variable (> 1- month), 2% Hybrid ARMs, 9% Fixed, 39% Loans by Rate Index(1,2) Earning Asset Composition & Interest Rate Sensitivity Cash flow hedge portfolio structured to mitigate asset sensitivity driven by loan portfolio mix with 52% variable rate Active interest rate swap hedge notional at quarter end was $800 million with a weighted average received fix rate of 3.27% and active floor notional was $75 million with a SOFR rate of 3.58% Active cash flow hedge notional of $875 million has an effective weighted average maturity of 3.5 years including effect of forward settle notional of $565 million in interest rate swaps and $75 million in interest rate floors Book Balance: $13.8B Yield(3): 6.21% As of 09/30/25 15 (1)Loans include LHFI & LHFS (2)Totals may not foot due to rounding (3)Loan Yield includes LHFI & LHFS (4)$ Millions $829 $765 $676 $496 $266 $70 $46 $93 $113 $81 $16 3.21% 3.34% 3.46% 3.58% 3.59% 3.64% 3.00% 3.10% 3.20% 3.30% 3.40% 3.50% 3.60% 3.70% 3.80% 3.90% 4.00% $- $100 $200 $300 $400 $500 $600 $700 $800 $900 $1,000 2025 2026 2027 2028 2029 2030 Hedge Notional (2)(4) Swap Notional (Annual Avg) Floor Notional (Annual Avg) Receive Fixed Rate (Annual Avg)

Loans Held for Investment (HFI) PortfolioFocus on profitable, credit-disciplined loan growth continued Loans HFI Loan Portfolio Composition 09/30/25(1)Change ($ in millions) (1) Other RE, 9/30/2025 LQ Y-o-Y 15% Loans secured by real estate: 24% Const., land dev. and other land loans $ 1,242 $ (113) $ (346) Secured by 1-4 family residential prop. 3,055 (2) 160C&I, 14% Secured by nonfarm, nonresidential prop. 3,300 (179) (283) Other real estate secured 2,056 137 580 Commercial and industrial loans 1,904 71 137 Consumer, 1% Consumer loans 151 2 2 State & Other Political 1-4 Residential, State and other political subdivision loans 1,028 67 32 Sub. , 8% 23% Other, 6% Other Loans & Leases 813 101 167 Construction, Total LHFI $ 13,548 $ 83 $ 448 Land Dev, 9%• Portfolio exhibits diversity by product type, geography, and industry Loans HFI by QuarterTotal loans to NDFIs of $292 million (2% of total loans): $13,548 $13,465 • $96 million to mortgage credit intermediaries $93 million to business credit intermediaries(2) $13,241 $52 million to consumer credit intermediaries $13,100 $13,090 • $51 million to other non-depository financial institutions Dollar Change: $(10) $151 $224 $83 private credit with total exposure of $137 • Minimal lending to million to six long term relationships, of which only $55 million Q3-24 Q4-24 Q1-25 Q2-25 Q3-25 (3) is funded and outstanding (<0.5% of total loans) (1) Totals and percentages may not foot due to rounding (2) This figure includes the referenced private credit in the last bullet below (3) Defined as direct loans made to mid-market businesses typically by non-bank vehicles such as private debt and Business Development Companies. Offering Company Q3’25 Historical Capital Net Interest Deposit Loan Asset Liquidity Noninterest Summary Overview Results Growth Position Income Portfolio Portfolio Quality Profile Inc. & Exp.

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. C&D / TRBC Ratio (%) CRE / TRBC Ratio (%)(1) Commercial & Construction Loan Concentrations Note: Financial data per bank level regulatory filings (1) Excludes non-owner occupied commercial real estate per regulatory definition 269% 281% 257% 249% 2022Y 2023Y 2024Y 2025Q3 105% 86% 71% 60% 2022Y 2023Y 2024Y 2025Q3 17

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. Commercial Real Estate and Offices (CRE) Portfolio Detail CRE Portfolio Focused on vertical construction with limited exposure to unimproved land and development Well-diversified product and geographical mix CRE Portfolio(1)(2) ($ in millions) 09/30/25 % of CRE Portfolio Lots, Development and Unimproved Land $ 254 5% 1-4 Family Construction 310 6% Other Construction 678 13% Total Construction, Land Development and Other Land Loans $ 1,242 24% Retail 262 5% Offices 228 4% Hotels/Motels 252 5% Industrial 464 9% Senior Living 283 5% Other 446 9% Total Non-owner Occupied & REITs $ 1,935 37% Multi-Family(3) 1,987 38% Total CRE $ 5,164 100%

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. Commercial Loan Portfolio Detail (1)All information provided above reflects outstanding balances (2)Totals and percentages may not foot due to rounding Portfolio includes commercial, financial intermediaries, agriculture production, equipment finance, non-profits, and leases Credits originated by the Equipment Finance line of business comprise $652 million of the commercial portfolio Well-diversified portfolio with no single category exceeding 15% Commercial Portfolio (1)(2) ($ in millions) 09/30/25 % of Commercial Portfolio Manufacturing $ 417 15% Wholesale Trade 350 13% Real Estate & Rental & Leasing 348 13% Finance & Insurance 287 11% Construction 279 10% Transportation & Warehousing 169 6% Administrative & Support & Waste Mgmt & Remediation Services 129 5% Retail Trade 128 5% Professional, Scientific & Technical Services 117 4% Health Care & Social Assistance 105 4% Information 92 3% Other 278 10% Total $ 2,699 100%

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. Strong Consistent History of Credit Risk Management (Loans HFI) $ % Allowance /Non-accrual Loans 182% 139% 200% 193% 208% 197% NPA/ Total Loans+ OREO 0.55% 0.81% 0.65% 0.71% 0.66% 0.67% $68 $86 $107 $90 $95 $92 $573 $524 $647 $644 $162 $331 $ % YTD YTD YTD 20 $135 $223 $434 $452 $412 $415 $27 $108 $213 $192 $161 $109 -15.00 -13.00 -11.00 -9.00 -7.00 -5.00 -3.00 -1.00 1.00 3.00 5.00 50 150 250 350 450 550 650 750 850 2022 2023 2024 Q1-25 Q2-25 Q3-25 Criticized & Classified Loans ($ in millions and %) Classified Loans Special Mention Loans Classified/Total Loans Criticized/Total Loans 0.99% 1.08% 1.22% 1.26% 1.25% 1.22% 2022 2023 2024 Q1- 25 Q2-25 Q3-25 Axis Title Allowance for Credit Losses/Loans $66 $100 $80 $87 $81 $84 $2 $7 $6 $8 $9 $8 2022 2023 2024 Q1-25 Q2-25 Q3-25 Nonperforming Assets ($ in millions) Nonaccrual Loans Other Real Estate 0.01% 0.06% 0.19% 0.04% 0.08% 0.10% 2022 2023 2024 Q1-25 Q2-25 Q3-25 Net Charge-offs/Average Loans 1.31 2.52 4.87 4.80 4.19 3.80 1.10 1.70 3.26 3.37 3.01 3.01

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. 0.87% 1.01% 0.95% 0.56% 0.30% (0.02%) (0.03%) 0.15% 0.10% 0.11% 0.19% 0.06% 0.02% (0.04%) 0.01% 0.06% 0.19% 0.10% 1.41% 2.56% 2.56% 1.57% 1.10% 0.69% 0.49% 0.44% 0.47% 0.50% 0.48% 0.51% 0.50% 0.25% 0.27% 0.51% 0.68% 0.64% 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 YTD TRMK National Average Strong Historical Credit Culture (1) Performance is based upon credits underwritten and approved by Trustmark (2) Sourced from Federal Reserve Economic Data; Includes all Commercial Banks (3) Data as of 6/30/25 YTD per Federal Reserve Economic Data Net Charge-Offs / Average Loans (1) (2) (3) 21

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. (Dollars in millions) Liquidity Available to TRMK 9/30/2025 On-Balance Sheet Liquidity FRBA Interest-Bearing Balance $454 Unencumbered Securities(1) 1,329 Total Liquidity Available on BS $1,783 Available Lines of Credit FHLB of Dallas Line(2) $2,020 Discount Window Line(2) 1,235 Upstream Federal Funds Line 280 Total Borrowing Capacity $3,535 Total Immediate Liquidity $5,318 86.7% 89.1% 87.8% 86.6% 86.0% 2025Q3 2025Q2 2025Q1 2024Q4 2024Q3 Liquidity Profile (1) Includes cash on deposit with the Federal Reserve Bank. (2) In 2025, Trustmark reallocated a substantial portion of its external credit facilities from the Federal Home Loan Bank (FHLB) to the Federal Reserve under its Borrower-In-Custody (BIC) program. This collateral represents an estimated incremental borrowing capacity of approximately $6 billion. Loans Held for Investment / Deposits (%) Calculation of Available Liquidity Cash & AFS Securities / Total Assets (%) 13.8% 12.4% 12.7% 13.0% 13.5% 2024Q3 2024Q4 2025Q1 2025Q2 2025Q3 22

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. Treasuries 2% Residential Pass- Through MBS 32% Other Residential MBS 8% Commercial MBS 58% Treasuries 11% U.S. Govt. Agency Obligation 4% Residential Pass- Through MBS 64% Commercial MBS 21% Investment Securities Portfolio (1) All commercial mortgage-backed securities issued or guaranteed by FNMA, FHLMC, or GNMA (2) Unrealized gains/losses shown on an after-tax basis; assumes a tax rate of 25.0% AFS Securities 59% of Portfolio $1.8B $1.3B HTM Securities 41% of Portfolio MRQ Securities Portfolio Composition Investment Portfolio Summary No corporate securities owned All securities owned are investment grade rated $345M Expected Cash Flow From Securities Over Next 12 Months 3.9 Years Effective Securities Portfolio Duration 4.4 Years Average Portfolio Life $22.0M Unrealized AT Gain on AFS Securities (2) $26.0M Unrealized AT Loss on HTM Securities (2) (1) (1) 23

Attractive Diversified Fee Income Business Noninterest Income – Q3-25(1) Noninterest Income(1) Change Other, net, 6% ($ in millions) Wealth Management, Q3-25 LQ Y-o-Y 25% Service Charges on Deposit Accounts Service Charges $ 11.3 $ 0.7 $ (0.0) on Deposit Accounts, 28% Bank Card and Other Fees 8.3 (0.4) 0.4 Mortgage Banking, net 8.2 (0.4) 2.1 Wealth Management 9.8 0.2 0.5 Other, net 2.4 0.1 (0.6)Total Noninterest Income $ 39.9 $ 0.0 $ 2.4 Mortgage Banking, net, Bank Card and 21% Other Fees, 21%Noninterest Income(1) ($ in millions)$41 $43$39 $40 $38 • Noninterest income in the third quarter totaled $39.9 million, up $41 $11 thousand linked-quarter and $2.4 million year-over-year. $11 $11 $11 $11$8 • Mortgage banking, net totaled $8.2 million in the third quarter, a decrease $9 $9 $8 of $420 thousand linked-quarter and an increase of $2.1 million year$8 over-year. The linked-quarter decrease was principally due to lower gain $7 $9$6 $9 $8 on sales of loans, net and increased net negative hedge ineffectiveness, $10 which was partly offset by increased mortgage servicing income, net. $9$9 $10 $10• Wealth Management revenue in the third quarter totaled $9.8 million, an $4 $6$3 $2 $2 increase of $160 thousand from the prior quarter and a $510 thousand Q3-24(1) Q4-24 Q1-25 Q2-25 Q3-25 increase from the previous year. Service Charges on Deposit Accounts Bank Card and Other Fees Mortgage Banking, net Wealth Management Other, net (1) Totals may not foot due to rounding Offering Company Q3’25 Historical Capital Net Interest Deposit Loan Asset Liquidity Noninterest Summary Overview Results Growth Position Income Portfolio Portfolio Quality Profile Inc. & Exp.

Company Overview Q3’25 Results Capital Position Net Interest Income Loan Portfolio Liquidity Profile Historical Growth Offering Summary Deposit Portfolio Asset Quality Noninterest Inc. & Exp. Income Statement Highlights – Noninterest Expense (1) Totals may not foot due to rounding Noninterest expense in the third quarter increased $5.8 million, or 4.7%, linked-quarter and included approximately $2.3 million in nonroutine items Salaries and employee benefits in the third quarter totaled $71.5 million, an increase of $3.2 million, or 4.7%, linked-quarter principally due to annual salary merit increases effective July 1 and general performance incentives Services and fees totaled $28.8 million in the third quarter, an increase of $1.8 million, or 6.6%, linked-quarter and included approximately $900 thousand in nonroutine items including professional fees related to the conversion to a state bank charter and other corporate strategic initiatives. Other real estate expense, net increased $1.8 million, which reflects the establishment of a $1.4 million reserve for a single property (2) $124 Q3-25 LQ Y-o-Y Salaries & Benefits 71.5 $ 3.2 $ 4.8 $ Services & Fees 28.8 1.8 3.1 Net Occupany—Premises 7.8 0.3 0.4 Equipment Expense 6.4 0.2 0.3 Other Expense 16.5 0.4 (0.9) Total Noninterest Expense 130.9 $ 5.8 $ 7.7 $ Noninterest Expense(1) ($ in millions) Change 25 $17 $15 $16 $16 $16 $6 $6 $6 $6 $6 $7 $7 $7 $8 $8 $26 $27 $26 $27 $29 $67 $69 $68 $68 $72 $123 $124 $125 $131 Q3-24 Q4-24 Q1-25 Q2-25 Q3-25 Noninterest Expense ($ in millions)(1) Salaries and Benefits Services & Fees Net Occupancy—Premises Equipment Expense Other Expense

Appendix

Current Ratings Profile Rating disclaimer: A rating is not a recommendation to buy, sell or hold securities. Ratings may be subject to revision or withdrawal at any time by the assigning rating organization. Each rating organization has its own methodology for assigning ratings and, accordingly, each rating should be evaluated independently of any other rating. S&P Global Ratings Fitch Ratings Trustmark Corporation Long-Term Issuer Rating BBB BBB Subordinated Debt BBB- BBB- Outlook Stable Stable

Historical Interest Coverage & Double Leverage Ratio * A reconciliation of this non-GAAP measure is set forth in appendix (1)Assumes net proceeds from subordinated debt raise are used to repay outstanding subordinated notes. (2)Pro forma earnings inclusive of adjustments to interest expense on subordinated debt, opportunity cost of cash, and the amortization of capitalized offering expenses. (3)Assumes a $125 million subordinated debt issuance at a market coupon rate. (4)Assumes repayment of $125 million aggregate principal amount of existing subordinated debt at 3.625% fixed rate coupon. Double Leverage($ in thousands)2023Y2024Y2025Q12025Q22025Q3Bank Level Equity$1,768,536$2,060,699$2,112,860$2,155,600$2,189,910Consolidated Equity1,661,8471,962,3272,021,2272,070,7892,114,268Double Leverage Ratio106.4%105.0%104.5%104.1%103.6%Pro Forma Bank Level Equity(1)$2,189,910iPro Forma Consolidated Equity(1)$2,113,418iiPro Forma Double Leverage Ratio103.6%= i / iiInterest Coverage($ in thousands)2023Y2024Y2025Q12025Q22025Q3Interest Expense on Debt$80,003$46,528$9,374$10,495$9,211AInterest Expense on Deposits245,951329,38167,71868,17771,065Total Interest Expense$325,954$375,909$77,092$78,672$80,276BIncome From Adjusted Continuing Operations Before Taxes*$188,940$222,224$65,334$68,856$69,754CInterest Coverage (excluding deposit expense)3.4x5.8x8.0x7.6x8.6x= (C + A) / AInterest Coverage (including deposit expense)1.6x1.6x1.8x1.9x1.9x= (C + B) / BPro Forma Pre-Tax Income(2)$68,925DIncremental Interest Expense from Subordinated Debt Raise(3)$1,914EIncremental Interest Expense Benefit from Subordinated Debt Redemption(4)1,133FPro Forma Earnings Before Interest Expense on Debt$78,917= D + E—F + APro Forma Earnings Before Interest Expense$149,982= D + E—F + BPro Forma Interest Coverage (excluding deposit expense)7.9x= (D + E—F + A) / (E—F + A)Pro Forma Interest Coverage (including deposit expense)1.9x= (D + E—F + B) / (E—F + B)28

Reconciliation of Non-GAAP Financial Measures ($ in thousands, except per share data) Quarter Nine Months Year Ended December 31,EndedEnded2022202320249/30/259/30/25Adjusted Continuing OperationsNet Interest Income (GAAP)a494,708$ 552,878$ 584,421$ 162,441$ 473,252$ Provision for Credit Losses (GAAP)b22,892 24,581 41,255 1,685 11,655 PCL, LHFI sale of 1-4 family mortgage loans— (8,633)—Provision for Credit Losses From Adjusted Continuing Operations (Non-GAAP)c22,892 24,581 32,622 1,685 11,655 Noninterest Income (Loss) (GAAP)d151,422 148,433 (23,419) 39,931 122,405 Mortgage Loan Sale Loss (incl in Other, Net)— 4,798 — Visa C Shares Gain (incl in Other, Net)— (8,056) — Securities (Gains) Losses, Net-—182,792 — Noninterest Income From Adjusted Continuing Operations (Non-GAAP)e151,422 148,433 156,115 39,931 122,405 Noninterest Expense (GAAP)f564,133 495,696 485,690 130,933 380,058 Litigation Settlement Expense(100,750) (6,500) ——Reduction in Force Expense- (1,406) ——Noninterest Expense From Adjusted Continuing Operations (Non-GAAP)g463,383 487,790 485,690 130,933 380,058 Income (Loss) From Continuing Operations Before Income Taxes (GAAP)a-b+d-f59,105 181,034 34,057 69,754 203,944 Income Taxes From Continuing Operations (GAAP)h(1,813) 27,744 (11,153) 12,967 37,683 Income (Loss) From Continuing Operations (GAAP)i60,918 153,290 45,210 56,787 166,261 Income From Adjusted Continuing Operations Before Income Taxes (Non-GAAP)a-c+e-g159,855 188,940 222,224 — Income Taxes From Adjusted Continuing Operations (Non-GAAP)23,374 29,720 35,889 — Income From Adjusted Continuing Operations (Non-GAAP)136,481$ 159,220$ 186,335$ -$ -$ Total Revenue (GAAP)a+d646,130$ 701,311$ 561,002$ 202,372$ 595,657$ Total Revenue (Non-GAAP)a+e646,130 701,311 740,536 202,372 595,657 Discontinued OperationsGain on Sale of FBBIj-$ -$ 228,272$ -$ -$ FBBI Operating Results—Noninterest Incomek53,722 58,525 28,255 — Noninterest Income53,722 58,525 256,527 — FBBI Operating Results—Noninterest Expensel39,080 42,223 19,375 — Income From Discontinued Operations (GAAP)m14,642 16,302 237,152 — Income Taxes From Discontinued Operations (GAAP)n3,673 4,103 59,353 — Income From Discontinued Operations (GAAP)o10,969$ 12,199$ 177,799$ -$ -$ Total Operating ResultsNet Interest Income (GAAP)a494,708$ 552,878$ 584,421$ 162,441$ 473,252$ Provision for Credit Losses (GAAP)b22,892 24,581 41,255 1,685 11,655 Noninterest Income (Loss) (GAAP)d151,422 148,433 (23,419) 39,931 122,405 Gain on Sale of FBBIj— 228,272 — FBBI Operating Results—Noninterest Incomek53,722 58,525 28,255 — Noninterest Income Total Operating Results (Non-GAAP)p205,144 206,958 233,108 39,931 122,405 Noninterest Expense (GAAP)f564,133 495,696 485,690 130,933 380,058 FBBI Operating Results—Noninterest Expensel39,080 42,223 19,375 — Noninterest Expense Total Operating Results (Non-GAAP)q603,213 537,919 505,065 130,933 380,058 Income From Total Operating Results (Non-GAAP)a-b+p-q73,747 197,336 271,209 69,754 203,944 Income Taxes From Total Operating Results (Non-GAAP)h+n1,860 31,847 48,200 12,967 37,683 Income From Total Results (GAAP)i+o71,887$ 165,489$ 223,009$ 56,787$ 166,261$ Diluted Per Share Data Diluted Earnings (Loss) per Share From Continuing Operations (GAAP)0.99$ 2.50$ 0.74$ 0.94$ 2.74$ Diluted Earnings per Share From Discontinued Operations (GAAP)0.18 0.20 2.90 — Diluted Earnings per Share Total (GAAP)1.17 2.70 3.63 0.94 2.74 Diluted Earnings per Share From Adjusted Continuing Operations (Non-GAAP)2.22 2.60 3.04 n/an/a Financial Ratios Return on Average Assets From Continuing Operations (GAAP)0.35%0.82%0.24%1.21%1.21%Return on Average Assets From Adjusted Continuing Operations (Non-GAAP)0.78%0.86%1.01%n/an/a Return on Average Tangible Common Equity From Continuing Operations (GAAP)4.86%12.43%3.04%12.84%13.03%Return on Average Tangible Common Equity From Adjusted Continuing Operations (Non-GAAP)10.78%12.95%12.71%n/an/a29

Return on Average Tangible Common Equity Reconciliation of Non-GAAP Financial Measures (1)Calculation = ((Net Income From Adjusted Continuing Operations Adjusted For Intangible Amortization/Number of Days in Period)*Number Of Days in Year)/Total Average Tangible Common Equity. ($ in thousands)Quarter Nine Months Year Ended December 31,EndedEnded2022202320249/30/259/30/25Average Tangible Common Equity Average Total Shareholders’ Equity1,608,299$ 1,565,740$ 1,801,797$ 2,090,373$ 2,041,407$ Less: Average Goodwill334,605 334,605 334,605 334,605 334,605 Less: Average Identifiable Intangible Assets971 325 182 49 80 Total Average Tangible Common Equity1,272,723$ 1,230,810$ 1,467,010$ 1,755,719$ 1,706,722$ Net Income From Continuing Operations Adjusted For Intangible AmorizationNet Income From Adjusted Continuing Operations136,481$ 159,220$ 186,335$ 56,787$ 166,261$ Plus: Intangible Amortization Net of Tax740 217 81 24 72 Net Income From Adjusted Continuing Operations Adjusted For Intangible Amortization137,221$ 159,437$ 186,416$ 56,811$ 166,333$ ROATCE From Adjusted Continuing Operations(1)10.78%12.95%12.71%12.84%13.03%30

Reconciliation of Non-GAAP Financial Measures ($ in thousands except for per share figures) Year Ended, Quarter Ended, 12/31/22 12/31/23 12/31/24 3/31/25 6/30/25 9/30/25 Tangible Common Equity Stockholders’ Equity $1,492,268 $1,661,847 $1,962,327 $2,021,227 $2,070,789 $2,114,268 Less: Goodwill and Other Intangibles 335,131 334,841 334,731 334,700 334,668 334,637 Tangible Common Equity (Non-GAAP) $1,157,137 $1,327,006 $1,627,596 $1,686,527 $1,736,121 $1,779,631 Tangible Assets Total Assets (GAAP) $18,015,478 $18,722,189 $18,152,422 $18,296,203 $18,615,659 $18,801,510 Less: Goodwill and Other Intangibles 335,131 334,841 334,731 334,700 334,668 334,637 Tangible Assets (Non-GAAP) $17,680,347 $18,387,348 $17,817,691 $17,961,503 $18,280,991 $18,466,873 Common Shares Outstanding 60,977,686 61,071,173 61,008,023 60,718,411 60,401,684 60,126,376 Tangible Common Equity to Tangible Assets Ratio (Non-GAAP) 6.5% 7.2% 9.1% 9.4% 9.5% 9.6% Tangible Book Value per Share (Non-GAAP) $18.98 $21.73 $26.68 $27.78 $28.74 $29.60 Tangible Common Equity & Tangible Book Value Per Share31

Reconciliation of Non-GAAP Financial Measures (1) Assumes a tax rate of 25.0% ($ in thousands) Quarter Ended, 9/30/25 After-Tax Unrealized Gain / (Loss) on HTM Securities Fair Value of HTM Securities $1,233,736 Less: Carrying Value of HTM Securities 1,268,459 Pre-Tax Unrealized Gain / (Loss) on HTM Securities ($34,723) After-Tax Unrealized Gain / (Loss) on HTM Securities(1) ($26,042) Tangible Common Equity Including After-Tax HTM Losses Stockholders’ Equity $2,114,268 Less: Goodwill and Other Intangibles 334,637 Tangible Common Equity (Non-GAAP) $1,779,631 Plus: After-Tax Unrealized Gain / (Loss) on HTM Securities (26,042) Tangible Common Equity Including After-Tax HTM Losses (Non-GAAP) $1,753,589 Tangible Assets Including After-Tax HTM Losses Total Assets (GAAP) $18,801,510 Less: Goodwill and Other Intangibles 334,637 Tangible Assets (Non-GAAP) $18,466,873 Plus: After-Tax Unrealized Gain / (Loss) on HTM Securities (26,042) Tangible Assets Including After-Tax HTM Losses (Non-GAAP) $18,440,831 Tangible Common Equity to Tangible Assets Ratio Including After-Tax HTM Losses (Non-GAAP) 9.5% Tangible Common Equity & Tangible Assets Including Unrealized Losses on HTM Securities32

Reconciliation of Non-GAAP Financial Measures (1)Assumes a tax rate of 25.0% (2)Includes other intangible assets, net of DTLs, disallowed deferred tax assets (DTAs), threshold deductions and transition adjustments, as applicable. Common Equity Tier 1 and Common Equity Tier 1 Including AOCI & After-Tax HTM Losses($ in thousands)Quarter Ended,9/30/25After-Tax Unrealized Gain / (Loss) on HTM Securities Fair Value of HTM Securities $1,233,736Less: Carrying Value of HTM Securities1,268,459Pre-Tax Unrealized Gain / (Loss) on HTM Securities($34,723)After-Tax Unrealized Gain / (Loss) on HTM Securities(1)($26,042)Common Equity Tier 1 Capital (CET1)Stockholders’ Equity$2,114,268Less: Accumulated Other Comprehensive Income (Loss) (AOCI)(19,380)Less: Goodwill Net of Associated Deferred Tax Liabilities320,754Less: Other Adjustments and Deductions for CET1(2)111Common Equity Tier 1 Capital (Non-GAAP)$1,812,783ACET1 Including AOCI & After-Tax HTM Losses Plus: Accumulated Other Comprehensive Income (Loss) (AOCI)(19,380)Plus: After-Tax Unrealized Gain / (Loss) on HTM Securities(26,042)Less: Unrealized Gain (Loss) on Cash Flow Hedges included in AOCI2,180CET1 Including AOCI & After-Tax HTM Losses (Non-GAAP)$1,765,181BRisk Weighted Assets$15,263,314CCET1 Capital Ratio11.9%= A / CCET1 Capital Ratio Including AOCI & After-Tax HTM Losses (Non-GAAP)11.6%= B / C33