Independent Bank Group, Inc. Fixed Income Investor Presentation July 2024

CAUTIONARY NOTE REGARDING FORWARD LOOKING STATEMENTS 2 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. This communication contains “forward-looking statements” within the meaning of the United States Private Securities Litigation Reform Act of 1995 that are subject to risks and uncertainties and are made pursuant to the safe harbor provisions of Section 27A of the Securities Act and Section 21E of the Securities Exchange Act of 1934, as amended, and other related federal securities laws. Forward-looking statements by their nature address matters that are, to different degrees, uncertain, including information about Independent Bank Group, Inc.’s (“IBTX”), SouthState Corporation’s (“SouthState”) or the combined company’s possible or assumed future results of operations, including its future revenues, income, expenses, provision for taxes, effective tax rate, earnings (loss) per share and cash flows, its future capital expenditures and dividends, its future financial condition and changes therein, including changes in IBTX’s, SouthState’s or the combined company’s loan portfolio and allowance for credit losses, IBTX’s, SouthState’s or the combined company’s future capital structure or changes therein, the plan and objectives of management for future operations, IBTX’s, SouthState’s or the combined company’s future or proposed acquisitions, the future or expected effect of acquisitions on IBTX’s, SouthState’s or the combined company’s operations, results of operations and financial condition, IBTX’s, SouthState’s or the combined company’s future economic performance and the statements of the assumptions underlying any such statement. Such statements are typically, but not exclusively, identified by the use in the statements of words or phrases such as “aim,” “anticipate,” “estimate,” “expect,” “goal,” “guidance,” “intend,” “is anticipated,” “is estimated,” “is expected,” “is intended,” “objective,” “plan,” “projected,” “projection,” “will affect,” “will be,” “will continue,” “will decrease,” “will grow,” “will impact,” “will increase,” “will incur,” “will reduce,” “will remain,” “will result,” “would be,” variations of such words or phrases (including where the word “could,” “may” or “would” is used rather than the word “will” in a phrase) and similar words and phrases indicating that the statement addresses some future result, occurrence, plan or objective. The forward-looking statements that IBTX and SouthState make are based on their current plans, estimates, expectations, ambitions and assumptions regarding IBTX’s, SouthState’s and the combined company’s business, the economy and other future conditions. Because forward-looking statements relate to future results and occurrences, they are subject to inherent uncertainties, risks and changes in circumstances that are difficult to predict and many of which are beyond the control of IBTX and SouthState. IBTX’s, SouthState’s and the combined company’s actual results may differ materially from those contemplated by the forward-looking statements, which are neither statements of historical fact nor guarantees or assurances of future performance. Many possible events or factors could affect IBTX’s, SouthState’s and the combined company’s future financial results and performance and could cause those results or performance to differ materially from those expressed in the forward-looking statements. In addition to factors previously disclosed in IBTX’s and SouthState’s reports filed with the U.S. Securities and Exchange Commission (the “SEC”), the following factors, among others, could cause actual results to differ materially from forward-looking statements or historical performance: (1) the occurrence of any event, change or other circumstance that could give rise to the right of one or both of the parties to terminate the definitive merger agreement between IBTX and SouthState providing for the acquisition of IBTX by SouthState (the “Transaction”); (2) the outcome of any legal proceedings that may be instituted against IBTX or SouthState; (3) the possibility that the Transaction does not close when expected or at all because required regulatory, shareholder or other approvals and other conditions to closing are not received or satisfied on a timely basis or at all (and the risk that such approvals may result in the imposition of conditions that could adversely affect the combined company or the expected benefits of the Transaction); (4) the risk that the benefits from the Transaction may not be fully realized or may take longer to realize than expected, including as a result of changes in, or problems arising from, general economic and market conditions, interest and exchange rates, monetary policy, laws and regulations and their enforcement, and the degree of competition in the geographic and business areas in which IBTX and SouthState operate; (5) disruption to the parties’ businesses as a result of the announcement and pendency of the Transaction; (6) the risk that the integration of each party’s operations will be materially delayed or will be more costly or difficult than expected or that the parties are otherwise unable to successfully integrate each party’s businesses into the other’s businesses; (7) the possibility that the Transaction may be more expensive to complete than anticipated, including as a result of unexpected factors or events; (8) reputational risk and potential adverse reactions of IBTX’s or SouthState’s customers, suppliers, employees or other business partners, including those resulting from the announcement or completion of the Transaction; (9) the dilution caused by SouthState’s issuance of additional shares of its capital stock in connection with the Transaction; (10) a material adverse change in the financial condition of SouthState or IBTX; (11) general competitive, economic, political and market conditions; (12) major catastrophes such as earthquakes, floods or other natural or human disasters, including infectious disease outbreaks; (13) the diversion of management’s attention and time from ongoing business operations and opportunities on merger-related matters; and (14) other factors that may affect future results of IBTX and SouthState including changes in asset quality and credit risk, the inability to sustain revenue and earnings growth, changes in interest rates and capital markets, inflation, customer borrowing, repayment, investment and deposit practices, the impact, extent and timing of technological changes, capital management activities and other actions of the Federal Reserve Board and legislative and regulatory actions and reforms. These factors are not necessarily all of the factors that could cause IBTX’s, SouthState’s or the combined company’s actual results, performance or achievements to differ materially from those expressed in or implied by any of the forward-looking statements. Other factors, including unknown or unpredictable factors, also could harm IBTX’s, SouthState’s or the combined company’s results. The projected financial information is intended to illustrate the potential impact of the Transaction on the Company based on the Company's current assumptions and beliefs. The projected financial information of the combined company included in this presentation are preliminary estimates based on information available to IBTX and SouthState management as of the date of this presentation. IBTX and SouthState urge you to consider all of these risks, uncertainties and other factors carefully in evaluating all such forward-looking statements made by IBTX and/or SouthState. As a result of these and other matters, including changes in facts, assumptions not being realized or other factors, the actual results relating to the subject matter of any forward-looking statement may differ materially from the anticipated results expressed or implied in that forward-looking statement. Any forward-looking statement made in this communication or made by IBTX or SouthState in any report, filing, document or information incorporated by reference in this communication, speaks only as of the date on which it is made. IBTX and SouthState undertake no obligation to update any such forward- looking statement, whether as a result of new information, future developments or otherwise, except as may be required by law. A forward-looking statement may include a statement of the assumptions or bases underlying the forward-looking statement. IBTX and SouthState believe that these assumptions or bases have been chosen in good faith and that they are reasonable. However, IBTX and SouthState caution you that assumptions as to future occurrences or results almost always vary from actual future occurrences or results, and the differences between assumptions and actual occurrences and results can be material. Therefore, IBTX and SouthState caution you not to place undue reliance on the forward-looking statements contained in this filing or incorporated by reference herein. If IBTX or SouthState update one or more forward-looking statements, no inference should be drawn that IBTX or SouthState will make additional updates with respect to those or other forward-looking statements. Further information regarding IBTX, SouthState and factors which could affect the forward-looking statements contained herein can be found in IBTX’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 (which is available at https://www.sec.gov/ix?doc=/Archives/edgar/data/1564618/000156461824000025/ibtx-20231231.htm), and its other filings with the SEC, and in SouthState’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 (which is available at https://www.sec.gov/ix?doc=/Archives/edgar/data/764038/000155837024002302/ssb-20231231x10k.htm), and its other filings with the SEC. In addition, the information on, or accessible through, our website, or any other website described herein, is not a part of, and is not incorporated or deemed to be incorporated by reference in, this presentation.

3 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. DISCLAIMER ADDITIONAL INFORMATION ABOUT THE TRANSACTION AND WHERE TO FIND IT SouthState has filed a registration statement on Form S-4 (the “Registration Statement”) with the SEC to register the shares of SouthState’s common stock that will be issued to IBTX shareholders in connection with the Transaction. The Registration Statement contains a joint proxy statement of SouthState and IBTX that also constitutes a prospectus of SouthState. The Registration Statement on Form S-4, as amended, was declared effective by the SEC on July 16, 2024, and on July 16, 2024, IBTX and SouthState each filed the definitive joint proxy statement/prospectus with the SEC. SouthState and IBTX commenced mailing the definitive joint proxy statement/prospectus to their respective shareholders on or about July 16, 2024. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE REGISTRATION STATEMENT ON FORM S-4, AND THE DEFINITIVE JOINT PROXY STATEMENT/PROSPECTUS INCLUDED WITHIN THE REGISTRATION STATEMENT ON FORM S-4, AS WELL AS ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC IN CONNECTION WITH THE TRANSACTION OR INCORPORATED BY REFERENCE THEREIN, BECAUSE THEY CONTAIN IMPORTANT INFORMATION REGARDING SOUTHSTATE, IBTX, THE TRANSACTION AND RELATED MATTERS Investors and security holders may obtain free copies of these documents and other documents filed with the SEC by IBTX or SouthState through the website maintained by the SEC or from SouthState at its website or from IBTX at its website. Documents filed with the SEC by SouthState will be available free of charge by accessing the “SEC Filings” tab of SouthState’s website or alternatively by directing a request by mail to SouthState’s Corporate Secretary, 1101 First Street South, Suite 202, Winter Haven, FL 33880, and documents filed with the SEC by IBTX will be available free of charge by accessing IBTX’s website under the “SEC Filings” tab or, alternatively, by directing a request by mail to IBTX’s Corporate Secretary, 7777 Henneman Way, McKinney, TX 75070-1711. PARTICIPANTS IN THE SOLICITATION IBTX, SouthState and certain of their respective directors and executive officers may be deemed to be participants in the solicitation of proxies from the shareholders of IBTX and SouthState in connection with the Transaction under the rules of the SEC. Information about the directors and executive officers of IBTX and their ownership of IBTX Common Stock is set forth in (i) the definitive joint proxy statement/prospectus related to the Transaction, including under the headings “Questions and Answers”, “Summary”, “The IBTX Special Meeting” “IBTX’s Reasons for the Merger; Recommendation of the IBTX Board of Directors”, “Interests of IBTX Directors and Executive Officers in the Merger” and “The Transaction Agreement – Description of the Support Agreements”, which was filed with the SEC by IBTX on July 16, 2024 (which is available at https://www.sec.gov/Archives/edgar/data/764038/000110465924080148/tm2417792-6_424b3.htm) and (ii) the definitive proxy statement for IBTX’s 2024 Annual Meeting of Shareholders, as filed with the SEC on Schedule 14A on April 26, 2024 (which is available at https://www.sec.gov/Archives/edgar/data/1564618/000110465924080226/tm2417792-7_defm14a.htm). Information about the directors and executive officers of IBTX, their ownership of IBTX Common Stock, and IBTX’s transactions with related persons is set forth in the sections entitled “Our Board of Directors”, “Compensation Discussion & Analysis”, “CEO Pay Ratio” and “Pay Versus Performance” of such definitive proxy statement. To the extent holdings of IBTX Common Stock by the directors and executive officers of IBTX have changed from the amounts of IBTX Common Stock held by such persons as reflected therein, such changes have been or will be reflected on Statements of Change in Ownership on Form 4 filed with the SEC, including: the Form 4s filed by Donald L. Poarch on July 3, Michael T. Viola on July 3, Janet P. Froetscher on July 3, G. Stacy Smith on July 3, Alicia K. Harrison on July 3, Craig E. Holmes on July 3, William E. Fair on July 3, Paul E. Washington on July 3, John Webb Jennings III on July 3, Paul B. Langdale on July 8, Brenda K. Montgomery on July 8, David R. Brooks on July 8 and July 18, Daniel W. Brooks on July 8 and July 18, Michael B. Hobbs on July 8 and July 18 and James P. Tippit on July 8 and July 18. Free copies of these documents may be obtained as described above. Information about the directors and executive officers of SouthState and their ownership of SouthState Common Stock can also be found in (i) the definitive joint proxy statement/prospectus related to the Transaction, including under the headings “Questions and Answers”, “Summary”, “The SouthState Special Meeting” “SouthState’s Reasons for the Merger; Recommendation of the SouthState Board of Directors”, “Interests of SouthState Directors and Executive Officers in the Merger” and “The Transaction Agreement – Description of the Support Agreements”, which was filed with the SEC by SouthState on July 16, 2024 (which is available at https://www.sec.gov/Archives/edgar/data/764038/000110465924080148/tm2417792-6_424b3.htm) and (ii) SouthState’s definitive proxy statement in connection with its 2024 Annual Meeting of Stockholders, as filed with the SEC on March 8, 2024 (which is available at https://www.sec.gov/ix?doc=/Archives/edgar/data/764038/000155837024002793/ssb-20240424xdef14a.htm) and other documents subsequently filed by SouthState with the SEC. Information about the directors and executive officers of SouthState, their ownership of SouthState Common Stock, and SouthState ’s transactions with related persons is set forth in the sections entitled “Our Directors”, “Director Independence”, “Related Person and Certain Other Transactions”, “Stock Ownership of Directors, Executive Officers, and Certain Beneficial Owners”, “Director Compensation”, “Compensation Discussion and Analysis”, “Compensation Committee Report”, “Executive Compensation”, “CEO Pay Ratio” and “Pay Versus Performance” of such definitive proxy statement, and the section entitled “Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters” of SouthState’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023, as filed with the SEC on March 4, 2024 (which is available at https://www.sec.gov/ix?doc=/Archives/edgar/data/764038/000155837024002302/ssb-20231231x10k.htm). To the extent holdings of SouthState Common Stock by the directors and executive officers of SouthState have changed from the amounts of SouthState Common Stock held by such persons as reflected therein, such changes have been or will be reflected on Statements of Change in Ownership on Form 4 filed with the SEC, including: the Form 4s filed by Sara Arana on March 6, Daniel Bockhorst on March 4 and March 20, Renee Brooks on March 4 and March 19, Ronald Cofield on May 2, Shantella Cooper on May 2 and May 8, John Corbett on March 4, Jean Davis on May 2, Martin Bernard Davis on May 2, Beth DeSimone on March 4, Douglas Hertz on May 2 and May 8, Greg Lapointe on March 4 and March 5, William Matthews V on March 4, Richard Murray IV on March 4 and March 21, G. Ruffner Page Jr. on May 2 and May 8, William Pou Jr. on May 2, James Roquemore on May 2, David Salyers on May 2, Joshua Snively on May 2 and June 13, Douglas Lloyd Williams on March 4 and Stephen Dean Young on March 4; and the Form 3 filed by Merrian Metz on July 26. Free copies of these documents may be obtained as described above.

DISCLAIMER (Continued) 4 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. NO OFFER OR SOLICITATION This communication shall not constitute an offer to sell or the solicitation of an offer to buy securities, nor shall there be any offer or sale of any securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful. Neither the SEC nor any other regulatory body has approved or disapproved of the securities of IBTX or passed upon the accuracy or adequacy of this communication. Any representation to the contrary is a criminal offense. Except as otherwise indicated, this presentation speaks as of the date hereof. The delivery of this communication shall not, under any circumstances, create any implication that there has been no change in the affairs of IBTX or SouthState after the date hereof. NON-GAAP FINANCIAL MEASURES In addition to results presented in accordance with GAAP, this presentation contains certain non-GAAP financial measures. These measures and ratios include “tangible common equity”, “return on average tangible common equity”, “adjusted return on average assets”, “tangible book value”, “tangible book value per common share”, “adjusted efficiency ratio”, “tangible common equity to tangible assets”, “adjusted return on average common equity”, “adjusted return on average tangible common equity”, “adjusted net income”, “net interest margin (tax equivalent)”, “net interest income (tax equivalent)”, “combined company earnings per share accretion excluding rate marks and CDI”, “combined company earnings accretion per share excluding rate marks, CDI and current expected credit losses”, “combined company tangible book value dilution excluding rate marks and CDI,” “combined company tangible book value dilution excluding rate marks, CDI and current expected credit losses,” “combined company tangible book value earnback excluding rate marks and CDI”, “combined company tangible book value earnback excluding rate marks, CDI and current expected credit losses”, adjusted noninterest expense”, “adjusted noninterest income to total revenue” and “adjusted noninterest expense to average assets” and are supplemental measures that are not required by, or are not presented in accordance with, accounting principles generally accepted in the United States. We believe that these measures provide useful information to management and investors that is supplementary to our financial condition, results of operations and cash flows computed in accordance with GAAP; however we acknowledge that our financial measures have a number of limitations relative to GAAP financial measures. Certain non-GAAP financial measures exclude items of income, expenditures, expenses, assets, or liabilities, including provisions for loan losses and the effect of goodwill, other intangible assets and income from accretion on acquired loans arising from purchase accounting adjustments, that we believe cause certain aspects of our results of operations or financial condition to be not indicative of our primary operating results. All of these items significantly impact our financial statements. Additionally, the items that we exclude in our adjustments are not necessarily consistent with the items that our peers may exclude from their results of operations and key financial measures and therefore may limit the comparability of similarly named financial measures and ratios. We compensate for these limitations by providing the equivalent GAAP measures whenever we present the non-GAAP financial measures and by including a reconciliation of the impact of the components adjusted for in the non- GAAP financial measure so that both measures and the individual components may be considered when analyzing our performance. A reconciliation of our non-GAAP financial measures to the comparable GAAP financial measures is included at the end of this presentation. ADDITIONAL INFORMATION ABOUT THE OFFERING IBTX has filed a shelf registration statement (File No. 333-272553) (including a base prospectus) and a preliminary prospectus supplement (the “Preliminary Prospectus Supplement”) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement, the Preliminary Prospectus Supplement and other documents IBTX has filed with the SEC for more complete information about IBTX and this offering. You may access these documents for free by visiting EDGAR on the SEC's website at www.sec.gov. Alternatively, IBTX, the underwriters 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 emailing Keefe, Bruyette & Woods, A Stifel Company at USCapitalMarkets@kbw.com or by calling U.S. Bancorp Investments, Inc. at 1-877-558-2607.

GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. PLANNED OFFERING OVERVIEW Issuer: Independent Bank Group, Inc. (Nasdaq: IBTX) Security Offered: Fixed-to-Floating Subordinated Notes Due 2034 Offering Size: $150 Million Expected Security Rating(1): BBB (POS*) Kroll Format: SEC Registered Term: 10 Years Call: 5 Years Use of Proceeds: To satisfy and discharge and/or repay all of the existing 5.875% subordinated notes due August 1, 2024 and for general corporate purposes Bookrunning Managers: *Following the announcement that SouthState plans to acquire Independent Bank Group, Inc. in an all-stock transaction, on May 21, 2024, KBRA revised the long-term ratings of Independent Bank Group, Inc. and its bank subsidiary, Independent Bank from Negative to Positive. This outlook was re-affirmed by KBRA in their report on July 24, 2024 Source: KBRA’s July 24, 2024 press release. (1) 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 5 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.

6 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. INDEPENDENT BANK GROUP, INC. SNAPSHOT Denver Austin Houston Dallas 92 Branches 1,505 Employees 1988 Year Founded Corporate Info and Footprint Headquarters: McKinney, Texas Ticker: Nasdaq: IBTX Chairman & CEO: David R. Brooks Markets: Metro Texas | Denver Balance Sheet Total Assets: $18.4B Net Loans: $14.5B Total Deposits: $15.8B Tangible Common Equity(1): $1.4B Asset Quality NPAs / Assets: 0.35% ACL / Gross Loans: 0.99% ACL / NPLs: 259% LTM NCOs / Avg. Loans: 0.03% Capital Ratios TCE / TA(1): 7.72% Leverage Ratio: 8.76% Tier 1 Capital Ratio: 10.03% Total Capital Ratio: 11.75% Founder-led organization High community involvement Conservative credit culture with history of resilient asset quality Granular loan portfolio with deep relationships across footprint in Texas and Colorado A Unique Community Bank Growth Story San Antonio Source: S&P Global. Note: IBTX Financials as of 6/30/2024. (1) Represents a non-GAAP measure. See appendix for non-GAAP reconciliation.

7 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. INVESTMENT HIGHLIGHTS Community bank holding company with $18.4 billion in assets and 92 financial centers across Texas and Colorado Innately conservative credit culture with a demonstrated history of maintaining asset quality through previous downturns, including strong NCO performance Highly granular loan portfolio with a small average credit size and low hold limits Loan growth driven by regional community banking: loans made to relationship borrowers across our footprint in Texas and Colorado Large insider ownership (approximately 13.4% of shares outstanding)(1) aligns shareholder interests with day-to-day management and decision making with a focus on risk management Disciplined growth both organically and through strategic acquisitions The SouthState transaction is expected to bolster IBTX positioning by: Providing the combined company with scale and diversification into similar high-growth markets Enhancing profitability profile while maintaining a strong capital base Minimizing interest rate risk position which provides stability given uncertainty in interest rate outlook Leveraging recent investments in technology and risk management into a ~$65B combined company regional bank Combining two institutions with history of resilient credit and management teams with acquisition / integration experience which mitigates execution risk (1) Per IBTX proxy statement dated as of 4/26/2024.

Merger Transaction Details

9 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. CREATING ONE OF THE SOUTH’S LEADING REGIONAL BANKS Enhanced Scale Through Partnership(1) Powerful Operating Leverage(4) 343 Branch Locations #5 Largest Regional Bank in the South(3) Dominant Southern Franchise Presence in 12 of 15 Fastest Growing U.S. MSAs(2) Projected Population Growth(6) Top 20% of U.S. MSAs highlighted in blue Combined Company Branch Footprint $65B Assets $48B Loans $55B Deposits 1.3% ROAA 18.0% ROATCE(5) 49% Efficiency Projected balances at merger close. Includes MSAs with greater than 1 million in total population. Note: The information presented on this slide reflect expectations regarding the (3) combined company and is inclusive of the assumptions detailed on slide 11. (4) SSB (251) IBTX (92) Virginia North Carolina South Carolina Georgia Florida Alabama Mississippi Louisiana Arkansas Tennessee Oklahoma Texas Colorado Excludes Bank of America, Capital One Financial, and Truist Financial. 2025 consensus estimates with cost savings fully phased in. Represents a non-GAAP measure. See Appendix for non-GAAP reconciliation. Source: S&P Global as of 7/11/2024. The map reflects the Top 20% of MSAs in the United States located in the Southeastern U.S. and Colorado.

10 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. TRA NSACTI ON RATIONALE Significant EPS accretion with manageable tangible book value dilution Peer leading pro forma profitability Conservative modeling assumptions Similar geographic business model with no market overlap promotes continuity with team members and customers Increases scale to leverage the recent investments in technology and risk management Acquisition and integration experience mitigates execution risk Creates a $65 billion financial institution in key growth markets in the United States Diversifies footprint into similar high-growth markets with a base of deep local connections Joins two granular customer bases with a history of resilient credit IBTX to merge into SSB; Independent Bank to merge into SouthState Bank 100% stock consideration; Fixed exchange ratio of 0.60x SSB shares for each IBTX share Anticipated closing by the end of the first quarter of 2025; subject to SSB and IBTX shareholder and regulatory approvals Deal Overview Strategically Compelling Financially Attractive Well-Positioned for Future Success

11 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. F INANCIAL ASSUMPTIONS Earnings Projections Based on consensus estimates for remaining periods of 2024 and 2025 with 5% and 5% annual long-term net income growth for SouthState and IBTX, respectively Interest Rate Marks $383.2 million pre-tax rate write-down on IBTX's loans (accreted into earnings over 3 years using straight-line amortization) $38.0 million pre-tax write-down on held-to-maturity securities (proceeds reinvested) $29.5 million pre-tax write-down on subordinated debt (amortized over 5.7 years straight-line) $11.9 million pre-tax write-up on trust preferred debt (amortized over 10 years straight-line) Merger Costs $139.6 million merger expenses, net of tax, fully reflected in pro forma TBV dilution at closing Targeted Cost Savings / Revenue Synergies Cost savings of 25% of IBTX’s 2025 non-interest expense base, grown at 3% per year Expected to be realized 50% in 2025, 100% thereafter Revenue synergies expected but not included in announced financial metrics Loan Credit Mark Estimates & CECL Double Count $207 million gross loan credit mark or 1.42% of IBTX's total loans $103.5 million (50%) allocated to purchase credit deteriorated (PCD) loans $103.5 million (50%) allocated to non-PCD loans (accreted into earnings over 3 years using straight-line amortization) Day two CECL reserve of $103.5 million non-PCD credit mark CDI Core deposit intangible of 3.0% of IBTX's core deposits (amortized over 10 years using sum-of-years-digits) Other Assumptions Sale and reinvestment of IBTX’s investment portfolio Note: Financial assumptions as of the date of the merger announcement.

12 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. North Texas 39 Branches Central Texas 9 Branches Greater Houston 13 Branches POSITI ONED FOR THE FUTURE I N KEY U.S. GROWTH MARKETS $4.5 $2.8 $1.9 $6.5 $1.5 $1.1 $1.0 $7.4 $1.1 $1.1 $1.7 Pro Forma Deposit Footprint Colorado Texas Louisiana Mississippi $1.8 Alabama Tennessee Georgia Dallas San Antonio Houston Augusta Atlanta $1.1 Jacksonville Gainesville Florida Pensacola I-4 Corridor Tampa Sarasota Huntsville Birmingham Austin Fort Collins Denver Colorado $1.5 Springs Colorado Front Range 31 Branches Source: S&P Global. Note 1: Pro forma deposit data as of 6/30/2023; Dollars in billions; Map includes all MSAs with more than $1B in deposits; Alabama and Virginia reflect aggregate state deposit balance. Note 2: I-4 Corridor includes Orlando, Daytona Beach, Tampa and Lakeland MSAs; Atlanta includes Atlanta-Sandy Springs-Alpharetta, Gainesville, and Athens-Clarke County MSAs. $0.5 Richmond Virginia Fort Lauderdale Miami North Carolina Raleigh $2.4 Charlotte $1.7 Greenville Columbia Orlando Savannah Mobile Pro Forma Deposits by State Florida 27% Texas 22% South Carolina 20% Georgia 16% Colorado 7% North Carolina 4% Alabama 4% Virginia 1% Oklahoma Arkansas Wilmington Myrtle Beach South Carolina Charleston

13 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. Stated 27.3% 2025 EPS Accretion(2) 9.6% TBV Dilution(1) 2.0 years TBV Earnback(1) Excluding Rate Marks/ CDI(1) 20.4% 2025 EPS Accretion(2) 2.0% TBV Dilution 0.9 years TBV Earnback Excluding Rate Marks/ CDI/CECL(1) 16.5% 2025 EPS Accretion(2) 0.4% TBV Dilution 0.3 years TBV Earnback Combined Company Earnings and TBV Impact FINANCIAL IMPACT OF THE SSB AND IBTX MERGER Note: The information presented on this slide reflect expectations regarding the combined company and is inclusive of the assumptions detailed on slide 11. Represents a non-GAAP measure. See Appendix for non-GAAP reconciliation. For illustrative purposes, assumes merger with SSB closes on 1/1/2025, cost savings are fully phased-in and excludes one-time deal costs.

14 2.50% 2.00% 1.50% 1.00% 0.50% 0.00% '07 '08 '09 '10 '11 '12 '13 Non-Performing Loans (“NPLs”) / Total Loans '14 '15 '16 '17 '18 '19 '20 '21 '22 '23 Q1'24 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. HISTORY OF RESILIENT CREDIT Source: S&P Global. Note 1: Financial data as of 3/31/2024. Note 2: Gray line represents aggregate data of current constituents of the KBW Nasdaq Regional Banking Index (KRX). Net Charge-Offs (“NCOs”) / Average Loans Peak NCOs: 0.31% Peak NCOs: 2.00% Peak NCOs: 1.94% SSB IBTX KBW Nasdaq Regional banking Index (KRX) 0.21% 0.03% 0.00% 5.00% 4.00% 3.00% 2.00% 1.00% 0.00% '07 '08 '11 '12 '13 '14 '15 '16 '17 '18 '19 '20 '21 '22 '23 Q1'24 Peak NPLs: 4.32% Peak NPLs: 2.80% Peak NPLs: 1.92% '09 '10 0.81% 0.55% 0.38%

15 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. Growth Company in High-Growth Markets Better not just Bigger Distinct Geographic Business Model Ownership Culture A Leadership Academy Growing Leaders VISION

Financial Overview

17 $37.8 $15.9 $15.0 $41.8 $43.9 $44.9 $45.5 $17.8 $18.7 $18.3 $19.0 $18.4 2022Y 2023Y 2024Q2 $24.7 $23.9 $11.4 $11.6 $30.2 $32.4 $33.2 $13.1 $12.4 $13.9 $14.7 $14.6 2024Q2 $30.7 $12.2 $11.9 $35.1 $36.4 $37.0 $37.1 $14.4 $15.6 $15.1 $15.7 $15.8 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. HISTORICAL BALANCE SHEET $1.3 $2.9 $3.1 $3.0 $3.5 $3.6 $1.2 $1.4 $1.5 $1.3 $1.4 $1.4 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 Total Assets ($bn) SSB IBTX Total Loans Held-for-Investment ($bn) SSB IBTX 2019Y 2020Y 2021Y Total Deposits ($bn) SSB IBTX 2019Y 2020Y 2021Y 2022Y 2023Y Tangible Common Equity(1) ($bn) SSB IBTX (1) Represents a non-GAAP measure. See Appendix for non-GAAP reconciliation.

18 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. TRACK RECORD OF STRONG PERFORMANCE 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 Adj. Return on Avg. Tangible Common Equity(1) (%) 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 Tangible Book Value Per Common Share(1) ($) Adjusted Return on Average Assets(1) (%) SSB IBTX Adjusted Return on Average Common Equity(1) (%) SSB IBTX SSB IBTX SSB IBTX 1.27% 0.98% 1.28% 1.34% 1.22% 1.51% 1.22% 1.20% 1.16% 1.17% 0.73% 0.53% 8.28% 7.81% 11.31% 10.59% 9.94% 9.94% 9.69% 8.62% 8. 91% 8. 59% 5.76% 4.41% $39.13 $41.16 $44.62 $46.32 $47.90 $ 28.99 $33.23 $35.25 $40.09 $ 32.25 $32.90 $33.27 2019Y 2020Y 2021Y (1) Represents a non-GAAP measure. See Appendix for non-GAAP reconciliation. 2022Y 2023Y 2024Q2 15.82% 14.14% 18.68% 18.40% 16.80% 16.05% 18.85% 15.58% 15.46% 15.20% 10.37% 7.40% 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2

19 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. TRACK RECORD OF STRONG PERFORMANCE (Continued) Net Interest Margin (Tax Equivalent)(1) (%) SSB IBTX Adjusted Efficiency Ratio(1) (%) SSB IBTX 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 Adjusted Noninterest Income / Adjusted Total Revenue(1) (%) SSB IBTX 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 Adjusted Noninterest Expense / Average Assets(1) (%) SSB IBTX 3.77% 3.26% 2.92% 3.44% 3.98% 3.57% 3.13% 3.37%3.49% 3.63% 2.76% 2.50% 56.53% 60.33% 59.88% 53.27% 55.52% 45.95% 46.04% 51 .04% 52.34% 54.20% 63.26% 71.09% 2.53% 2.34% 2.18% 2.02% 2.14% 2.15% 1.87% 1.75% 1.68% 1.91% 1.80% 1.87% 2019Y 2020Y 2021Y (1) Represents a non-GAAP measure. See Appendix for non-GAAP reconciliation. 2022Y 2023Y 2024Q2 21.8% 27.3% 25.5% 18.8% 16.5% 17.7% 11 .6% 13 .4% 11 .3% 8.8% 10 .2% 11 .3% 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2

20 8.88% 8.10% 7.71% 7.25% 8.21% 8.39% 8.98% 8.60% 8.53% 7.72% 7.55% 7.72% 2022Y 2023Y 2024Q2 9.73% 9.32% 8.27% 8.08% 9.70% 9.12% 8.80% 8.72% 9.49%9.42% 8.94% 8.76% 2022Y 2023Y 2024Q2 12.25% 11.77% 11.76% 11.75% 12.10% 10.19% 10.74% 11.52%10.96% 10.45% 9.93% 10.03% 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. CONSOLIDATED CAPITAL RATIOS 12.78% 14.24% 13.57% 14.08% 14.40% 11.83% 13.32% 13.67%12.97% 12.35% 11.57% 11.75% 2019Y 2020Y 2021Y (1) Represents a non-GAAP measure. See Appendix for non-GAAP reconciliation. 2022Y 2023Y 2024Q2 Tangible Common Equity / Tangible Assets(1) (%) SSB IBTX Leverage Ratio (%) SSB IBTX 2019Y 2020Y 2021Y Tier 1 Capital Ratio (%) SSB IBTX 2019Y 2020Y 2021Y Total Capital Ratio (%) SSB IBTX

222% 225% 221%237% 237%244% 243%249% 230%237% 227%231% 383% 326% 337% 401% 440% 431% 374% 319% 325% 386% 411% 401% 68%69% 52%56% 55%56% 63% 58%60% 50%51% 65% 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 REGULATORY CRE AND C&D CONCENTRATION RATIOS IBTX Regulatory CRE / Total Capital (%) 107% 86% 90% 93% 82% 104% 84% 81%79% 87% 87% 76% 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 SSB Regulatory CRE / Total Capital (%) Consolidated Bank Level 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 SSB Regulatory C&D / Total Capital (%) Consolidated Bank Level Consolidated Bank Level 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 IBTX Regulatory C&D / Total Capital (%) Consolidated Bank Level 21 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER.

IBTX Loan Portfolio and Credit Quality

IBTX – LOAN PORTFOLIO OVERVIEW AS OF JUNE 30, 2024 CRE 57.5% Mortgage Warehouse 4.3% 1-4 Family 11.6% Consumer 0.5% 1-4 Family Construction 2.9% C&I 14.7% Agricultural 0.8% Construction & Development 7.7% North Texas 35.3% Central Texas 12.8% Houston 25.1% Colorado 26.8% Loan Portfolio by Industry Loan Portfolio by Geography $14.6B Loans Held for Investment 6.03% Q2’24 Loan Yield 0.38% NPLs / Loans HFI 0.10% Q2’24 NCOs / Avg. Loans 258.83% Allowance / NPLs Owner Occupied 21.3% Non-Owner Occupied 78.7% 23 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER.

IBTX – COMMERCIAL REAL ESTATE PORTFOLIO AS OF JUNE 30, 2024 Total CRE Loans: $8.4B $37.9M Largest CRE Loan Size $1.8M Average CRE Loan Size 21.3% Owner Occupied Office and Office Warehouse 17.9% 24 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. Retail 29.7% Hotel/Motel 4.4% Industrial 11.5% Daycare/School 2.6% Healthcare 5.5% Church 1.4% Convenience Store 3.8% Mini Storage 1.5% 2.0% Miscellaneous 3.8% Restaurant 0.2% Dealerships 0.9% Mixed Use (Non-Retail) RV & Mobile Home Parks 1.5% Multifamily 13.3%

25 Healthcare 1.5% Misc. CRE 16.9% Retail 30.5% Office / Warehouse 6.1% Hotel / Motel 2.5% Industrial 4.4% Multifamily 38.1% CRE Construction 39.7% Single Family Residential Construction 26.4% Land / Land Development 33.9% GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. IBTX – CONSTRUCTION / LAND DEVELOPMENT PORTFOLIO AS OF JUNE 30, 2024 C&D Portfolio(1) CRE Construction Portfolio 76% C&D / Bank Regulatory Capital 97.8% Loans in IBTX Markets(1) (Texas and Colorado) $2.2M Average Loan Size(1) 588 C&D Loans(1) 33.2% Owner Occupied C&D Loans(1) (1) Includes loans greater than $500,000. Total C&D: $1.6B

Office Non-Owner Occupied 49.0% Office Owner Occupied 16.7% Office / Warehouse Non- Owner Occupied 22.4% Office / Warehouse Owner Occupied 11.9% IBTX – OFFICE CRE / C&D PORTFOLIO AS OF JUNE 30, 2024 26 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. $23.6M Largest Office Loan $1.3M Average Loan Size 28.6% Owner Occupied 34.3% Office / Warehouse Total Office CRE / C&D: $1.5B

Strip Center 65.7% Free Standing / Single Tenant 12.5% Big Box 1.4% Mixed Use 20.4% IBTX – RETAIL CRE / C&D PORTFOLIO AS OF JUNE 30, 2024 27 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. $31.1M Largest Retail Loan 1,052 Total Retail Loans 88.9% Loans in IBTX Markets (Texas and Colorado) $2.5M Average Loan Size 151 Number of Loans > $5M $10.0M Avg. Size of Loans > $5M Total Retail CRE / C&D: $2.7B

IBTX – HOTEL / MOTEL PORTFOLIO AS OF JUNE 30, 2024 $5.6M Average Loan Size 51.2% Average Loan-to-Value Total Hotel / Motel Portfolio: $384.1M CRE 96.5% Construction & Development 3.5% Texas 48.5% Colorado 36.3% Other 15.2% Limited / Selected Service Brand 71.6% Boutique / Independent 5.9% Full Service Brand 22.5% Hotel Loans by Type Hotel Loans by Property Location Hotel Loans by Product Type 28 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. Granular book of hotel loans, the majority of which are branded or limited / selected service properties in IBTX core markets across Texas and Colorado

E&P $654.1 M 99% Services $4.6 M 1% IBTX – ENERGY LENDING AS OF JUNE 30, 2024 29 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. Energy assets are well-diversified by basin across the United States 1.4% Energy Reserves / Energy Loans 4.7% Energy Loans / Total Loans HFI Total Energy Portfolio: $658.7M

30 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. IBTX – CONSERVATIVE CREDIT CULTURE 0.76% 0.47% 1.28% 1.09% 1.07% 0.99% 2019Y(2) 2020Y(2) 2021Y 2022Y 2023Y ACL / Non-Performing Loans (%) 2024Q2 ACL / Loans Held for Investment(1) (%) 193% 171% 259% 371% 293% 259% 2019Y(2) 2020Y (2) 2021Y 2022Y 2023Y 2024Q2 Loan Category Loan Balance ($mm) Allowance for Credit Losses ($mm) Allowance for Credit Losses (% of Loans) Commercial $2,152.8 $35.2 1.64% Mortgage Warehouse Purchase Loans $633.6 $0.0 0.00% Commercial Real Estate $8,406.5 $64.2 0.76% Commercial Construction & Development $1,131.4 $24.7 2.18% Single-family Interim Construction $427.7 $12.7 2.97% Residential Real Estate $1,687.2 $7.5 0.44% Agricultural $110.4 $0.6 0.54% Consumer $72.2 $0.4 0.55% Total Loans Held for Investment ("LHFI") $14,621.8 $145.3 0.99% Total LHFI (excl. Mortgage Warehouse) $13,988.2 $145.3 1.04% Excludes mortgage warehouse purchase loans. Prior to CECL adoption. Allowance for Credit Losses (“ACL”) by Loan Type as of June 30, 2024

SSB Loan Portfolio and Credit Quality

32 Consumer RE 25% Owner- Occupied CRE 17% Cons / Other 4% C&I 17% Total Loans $33.2 Billion Investor CRE (2) 29% CDL(1) 8% GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. SSB – LOAN PORTFOLIO OVERVIEW AS OF JUNE 30, 2024 Loan Type No. of Loans Balance Avg. Loan Balance Investor CRE 7,947 $ 9.7B $ 1,224,600 Consumer RE 45,512 8.4B 185,500 Owner-Occupied CRE 7,677 5.5B 719,500 C & I 19,488 5.8B 296,000 Constr., Dev. & Land 3,018 2.6B 858,900 Cons / Other(3) 54,236 1.0B 19,100 Total 137,878 $ 33.1B $ 240,000 Loan Relationships Top 10 Top 20 Represents ~2% of total loans Represents ~4% of total loans SNC loans represent approximately 2% of total outstanding loans at June 30, 2024 CDL includes residential construction, commercial construction, and all land development loans. Investor CRE includes non owner-occupied CRE and other income producing property. Excludes SELF loans acquired from ACBI.

33 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. SSB – NON OWNER-OCCUPIED COMMERCIAL REAL ESTATE PORTFOLIO AS OF JUNE 30, 2024 (2) Weighted average DSC information from SSB’s 12/31/2023 stress test using commitment balances, totaling ~$5.4B; excludes loans below $1.5M, unless part of a larger relationship. Weighted average LTV as of 6/30/2024. (1) Includes loan types representing 2% or more of investor CRE portfolio; based on the total portfolio (3) Represents % of each of $9.1B, excluding 1-4 family rental properties and agricultural loans. loan type balance.

34 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. SSB – COMMERCIAL REAL ESTATE MATURITIES BY YEAR(1) $0.7 $1.3 $1.9 $1.7 $1.6 $8.1 8% 4% 13% 11% 10% 53% $0.0 $1.0 $2.0 $3.0 $4.0 $5.0 $6.0 $7.0 $8.0 $9.0 2024 2025 2026 2027 2028 2029 & Beyond $ in billions 87% CRE loans mature in 2026 or later (1) Includes agricultural and 1-4 family rental properties loans.

35 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. SSB – OFFICE PORTFOLIO AS OF JUNE 30, 2024 FL 43% SC 21% GA 18% VA 6% AL 2% Other 5% NC 5% Office represents 4% of the loan portfolio Average loan size only $1.4 million 95% located in the SouthState footprint Approximately 10% is located within the Central Business District(1) 81% of the portfolio is less than 150K square feet(1) 81% mature in 2026 or later 58% weighted average Loan to Value(2) 1.47x weighted average Debt Service Coverage(2) Office Portfolio By State Office Portfolio By Metropolitan Statistical Area Review consists of all loans over $1 million. Substantially all loans reviewed in the $1 million to $1.5 million population were 50,000 square feet or smaller and were not located in a Central Business District. Weighted average DSC information from SSB’s 12/31/2023 stress test using commitment balances, totaling ~$5.4B; excludes loans below $1.5M, unless part of a larger relationship. Weighted average LTV as of 6/30/2024.

36 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. SSB – CONSERVATIVE CREDIT CULTURE 0.62% 1.85% 1.26% 1.18% 1.41% 1.42% 2019Y(1) 2020Y 2021Y 2022Y 2023Y ACL / Non-Performing Loans (%) 2024Q2 ACL / Total Loans (%) 250% 428% 376% 328% 250% 241% 2019Y(1) 2020Y 2021Y 2022Y 2023Y 2024Q2 Allowance for Credit Losses (“ACL”) by Loan Type as of June 30, 2024 Loan Category Loan Balance ($mm) Allowance for Credit Losses ($mm) Allowance for Credit Losses (% of Loans) Construction and Land Development $2,592.3 $87.2 3.36% Commerical Non-owner Occupied $9,106.8 $118.8 1.30% Commerical Owner Occupied Real Estate $5,523.0 $91.5 1.66% Consumer Owner Occupied $6,969.3 $60.0 0.86% Home Equity Lines $1,471.4 $18.9 1.28% Commercial and Industrial $5,769.8 $81.9 1.42% Other Income Producing Properties $625.0 $1.8 0.29% Consumer $1,175.1 $12.2 1.04% Other Loans $1.8 N/D - Total $33,234.5 $472.3 1.42% (1) Prior to CECL adoption.

Combined Company Loans, Deposits and Funding Overview

38 Construction & Land Dev. 7.8% Non-Owner Occupied CRE 29.3% Commercial & Industrial 17.4% Owner Occupied CRE 16.6% 25.4% Total Loans: $33.2B Consumer / Other 3.5% 1-4 Family Non-Owner Occupied CRE 45.2% Commercial & Industrial 14.7% Owner Occupied CRE 12.2% Mortgage Warehouse 4.3% Consumer / Other 1.2% Construction & Land Dev. 7.7% Non-Owner Occupied CRE 34.2% Owner Occupied CRE 15.3% Commercial & Industrial 16.6% 1-4 Family 22.1% Mortgage Warehouse 1.3% Consumer / Other 2.8% Construction & Land Dev. 7.8% GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. COMBINED COMPANY LOAN COMPOSITION AS OF JUNE 30, 2024 Q2’24 Yield on Loans: 5.82% CRE Concentration: 227% C&D Concentration: 50% SouthState Corporation(1) Independent Bank Group, Inc. Combined Company(2) Total Loans: $14.6B 1-4 Family (3) 14.5% Total Loans: $47.9B Source: SSB and IBTX earnings releases. SSB balances and yields exclude loans held-for-sale. Excludes purchase accounting adjustments. Includes 1-4 family real estate and 1-4 family construction. Q2’24 Yield on Loans: 6.03% CRE Concentration: 431% C&D Concentration: 82% Q2’24 Yield on Loans: 5.88% CRE Concentration: 282% C&D Concentration: 58%

39 Noninterest- bearing Checking 28.0% Interest-bearing Checking 20.3% Savings 6.7% Money market 32.7% Time Deposits 12.3% Noninterest- bearing Checking 26.0% Interest- bearing Checking 21.0% Savings 5.6% Money market 26.7% Public Funds 4.2% Time Deposits 16.4% GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. COMBINED COMPANY DEPOSIT COMPOSITION AS OF JUNE 30, 2024 Q2’24 Cost of Deposits: 1.80% Loans / Deposits: 89.6% SouthState Corporation Independent Bank Group, Inc. Combined Company(1) Total Deposits: $37.1B Total Deposits: $15.8B Total Deposits: $52.9B Q2’24 Cost of Deposits: 3.22% Loans / Deposits: 92.3% Q2’24 Cost of Deposits: 2.22% Loans / Deposits: 90.4% Source: SSB and IBTX earnings releases. (1) Excludes purchase accounting adjustments. Noninterest- bearing Checking 21.3% Interest-bearing Checking 22.7% Savings 3.2% Money market 12.7% Public Funds 14.2% Time Deposits 25.9%

40 86.4% 87.8% 92.0% 93.3% 88.5% 87.7% 2019Y 2020Y 2021Y 2022Y SSB Historical Cost of Deposits 2023Y 2024Q2 0.10% 1.20% 1.80% 1.75% 0.56% 0.25% 0.24% 0.25% 0.10% 4.50% Fed Funds Rate 5.50% 5.50% 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. DEPOSIT PORTFOLIO TRENDS SSB Core Deposits(1) / Total Deposits (%) IBTX Core Deposits(1) / Total Deposits (%) 2019Y 2020Y 2021Y 2022Y IBTX Historical Cost of Deposits 0.52% 2.40% 3.22% 1.75% 1.08% 0.59% 0.25% 0.29% 0.25% 4.50% 5.50% Fed Funds Rate 5.50% 2019Y 2020Y Core deposits are defined as total deposits less all time deposits. Current cycle defined as Q4 2021 to Q2 2024. 2021Y 2022Y 2023Y 2024Q2 SSB Total Cost of Deposits 84.7% 90.2% 93.2% 90.6% 72.8% 74.1% 2023Y 2024Q2 IBTX Total Cost of Deposits Current Cycle Deposit Beta(2): 33.1% Current Cycle Deposit Beta(2): 57.0%

41 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. CONSERVATIVE SECURITIES PORTFOLIO AS OF JUNE 30, 2024 Available for Sale Securities ($mm) Held to Maturity Securities ($mm) SSB IBTX Mortage- Backed Securities $2,948.4 Government Agency Securities $195.1 Obligations $952.7 Corporate Obligations $27.3 U.S. Treasuries $37.9 State and Municipal Other $336.7 Mortage- Backed Securities $673.4 Government Agency Securities $394.6 State and Municipal Obligations $217.9 $171.6 Corporate Obligations $36.4 U.S. Treasuries Other $0.5 Mortage- Backed Securities $2,149.8 Government Agency Securities $147.3 Other $51.5 State and Municipal Obligations $204.3 Total : $4.5B Total : $1.5B Total : $2.3B Total : $0.2B Note: Available for sale securities balances are shown as fair value and held to maturity securities are shown as amortized cost. (1) % of AFS is calculated as unrealized loss, net of taxes, divided by amortized cost of AFS portfolio. 2.39% Q2’24 Yield 7.17 years Duration 9.3% Of Total Assets -$190.1M (13%) AOCI, net of taxes (% of AFS(1)) 2.48% Q2’24 Yield 5.89 years Duration 15.0% Of Total Assets -$620.8M (12%) AOCI, net of taxes (% of AFS(1))

42 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. LIQUIDITY OVERVIEW AS OF JUNE 30, 2024 SSB IBTX (1) Net of any outstanding balances as of 6/30/2024 and excludes cash balances. Sources of Liquidity Loans HFI / Deposit Ratio (%) 97% 91% 80% 92% 94% 92% 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 93% 80% 68% 83% 87% 90% 2019Y 2020Y 2021Y 2022Y 2023Y 2024Q2 Source of Short-Term Liquidity Amount(1) ($mm) Unsecured Fed Funds Lines Available from Commercial Banks $405.0 American Financial Exchange (overnight borrowings) $474.0 Unused Borrowing Capacity from FHLB $5,181.0 Unused Borrowing Capacity under Fed Discount Window $1,134.9 Unused Portion of Line of Credit $66.3 Source of Short-Term Liquidity Amount(1) ($mm) Federal Home Loan Bank of Atlanta $6,254.8 Federal Reserve Bank of Atlanta Discount Window $1,783.3 Fair Value of Unpledged Securities $2,865.1

43 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. INTEREST RATE SENSITIVITY AS OF JUNE 30, 2024 Percentage Change in Projected Net Interest Income from Baseline Over 1 Year (1.6%) 0.9% 1.5% 4.0% (4.5%) (10.5%) +200 bps -100 bps +100 bps Note: The figures above illustrate the impact of an immediate and sustained decrease or increase in interest rate on net interest income over the 12 months based on SSB’s and IBTX’s interest rate sensitivity models. SSB IBTX

Capital, Historical Interest Coverage and Debt Schedule

45 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. ESTIMATED EFFECT OF SUBDEBT RAISE ON IBTX STANDALONE RATIOS AS OF JUNE 30, 2024 82% 76% Standalone Adjusted for this offering and repayment of outstanding notes due 2024 (1) 431% 400% Standalone Adjusted for this offering and repayment of outstanding notes due 2024 (1) (1) For illustrative purposes, gives effect to the repayment in full at maturity of $110 million 5.875% fixed rate subordinated notes due 8/1/2024 and raise of $150 million subordinated debt. Standalone Adjusted for this offering and repayment of outstanding notes due 2024 (1) Total Capital Ratio (%) 12.67% 11.75% Regulatory C&D / Total Capital (%) Regulatory CRE / Total Capital (%)

GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. EFFECT OF SUBDEBT RAISE ON COMBINED COMPANY RATIOS AS OF MARCH 31, 2024 *Note: Based off SSB and IBTX 3/31/2024 balance sheet. Note: The information presented on this slide reflect expectations regarding the combined company and is inclusive of the assumptions detailed on slide 11 and the sale of mortgage warehouse loans. 46 Interest rate marks include reversal of IBTX’s existing loan discount and existing fair market value adjustments on subordinated debt and trust preferred. For illustrative purposes, gives effect to the repayment in full at maturity of $110 million 5.875% fixed rate subordinated notes due 8/1/2024 and raise of $150 million subordinated debt. Combined Company Capital INCLUDING Interest Rate Purchase Accounting Marks* Without Subdebt Raise With Subdebt Raise(2) Combined Company Capital EXCLUDING Interest Rate Purchase Accounting Marks* Leverage Ratio 8.24% 8.24% Leverage Ratio 8.67% 8.67% Without Subdebt Raise With Subdebt Raise(2) Tier 1 Capital Ratio 10.05% 10.05% Tier 1 Capital Ratio 10.54% 10.54% Total Capital Ratio 12.20% 12.49% Total Capital Ratio 12.67% 12.97% Interest Rate Marks: $382.6M(1)

47 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. IBTX – HISTORICAL DOUBLE LEVERAGE AND INTEREST COVERAGE (1) For illustrative purposes, gives effect to the repayment in full at maturity of $110 million fixed rate subordinated notes with 5.875% annual coupon rate and raise of $150 million subordinated debt with 8.50% annual coupon rate and 2 years of interest coverage held at the holding company. As adjusted for ($ Thousands) FY 2019 FY 2020 FY 2021 FY 2022 FY 2023 Q2'24 this offering(1) Bank level equity $ 2,588,267 $ 2,875,550 $ 2,903,617 $ 2,700,494 $ 2,722,515 $ 2,221,549 $ 2,233,799 Consolidated equity 2,339,773 2,515,371 2,576,650 2,385,383 2,402,593 1,897,083 1,897,083 Double leverage ratio 111% 114% 113% 113% 113% 117% 118% Interest Coverage Earnings: Income from continuing operations before taxes $ 246,264 $ 252,382 $ 282,233 $ 246,295 $ 52,318 $ (488,330) $ (489,902) (+) Goodwill Impairment - - - - - 518,000 518,000 (+) Interest on advances from the FHLB 10,173 4,170 2,038 2,017 35,705 1,750 1,750 (+) Interest on other borrowings including existing subordinated debt 11,590 12,462 15,247 14,451 16,018 5,716 4,100 (+) Interest on junior subordinated debentures 3,028 2,162 1,756 2,713 4,725 1,223 1,223 (+) Interest Attributable to $150MM Subordinated Debt Raise - - - - - - 3,188 Earnings available to pay down interest on other borrowings (net of deposit interest expense) 271,055 271,176 301,274 265,476 108,766 38,359 38,359 A (+) Interest on deposits 123,384 76,266 44,199 77,628 358,405 125,248 125,248 Earnings available to pay down interest on deposits and other borrowings $ 394,439 $ 347,442 $ 345,473 $ 343,104 $ 467,171 $ 163,607 $ 163,607 B Interest Expense: Interest on advances from the FHLB $ 10,173 $ 4,170 $ 2,038 $ 2,017 $ 35,705 $ 1,750 $ 1,750 Interest on other borrowings including existing subordinated debt 11,590 12,462 15,247 14,451 16,018 5,716 4,100 Interest on junior subordinated debentures 3,028 2,162 1,756 2,713 4,725 1,223 1,223 Interest Attributable to $150MM Subordinated Debt Raise - - - - - - 3,188 Interest expense on other borrowings (excluding interest on deposits) 24,791 18,794 19,041 19,181 56,448 8,689 10,261 C Interest on deposits 123,384 76,266 44,199 77,628 358,405 125,248 125,248 Total interest expense (including interest on deposits) $ 148,175 $ 95,060 $ 63,240 $ 96,809 $ 414,853 $ 133,937 $ 135,509 D Interest coverage on other borrowings (excluding deposit interest expense) - A / C Interest coverage on deposits and other borrowings - B / D 10.9x 2.7x 14.4x 3.7x 15.8x 5.5x 13.8x 3.5x 1.9x 1.1x 4.4x 1.2x 3.7x 1.2x

48 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. CURRENT OUTSTANDING DEBT SCHEDULE Term / Structure Company Rank Maturity Date Call Date Amount ($000) Front-End Coupon Back-End Coupon Current Coupon 10yr IBTX Subordinated 8/1/2024 - $110,000 5.875% - 5.875% 10yr NC 5 SSB Subordinated 6/1/2030 6/1/2025 $200,000 5.75% 3m SOFR + 561.7 bps 5.75% 10yr NC 5 SSB Subordinated 9/1/2030 9/1/2025 $75,000 5.50% 3m SOFR + 536.3 bps 5.50% 10yr NC 5 IBTX Subordinated 9/15/2030 9/15/2025 $130,000 4.00% 3m SOFR + 388.5 bps 4.00% Trust Preferred IBTX Junior Subordinated March 2033 to Sept. 2037 Currently Callable $57,324 - - 8.99%(1) Trust Preferred SSB Junior Subordinated Oct. 2033 to March 2037 Currently Callable $117,637(2) - - 7.34%(2) Note: The table does not include any borrowings from government agencies or revolving lines of credit. Annualized rate for the 3 months ended 6/30/2024. Balance and interest rate as of 12/31/2023 per SSB’s latest 10-K filing for the year ended December 31, 2023. Ordered by maturity date

Appendix

50 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. HISTORICAL FINANCIALS – IBTX For the 3 Months Ending, 2019 2020 2021 2022 2023 6/30/2024 Balance Sheet ($000) Tota l Assets $ 14,958.2 $ 17,753.5 $ 18,732.6 $ 18,258.4 $ 19,035.1 $ 18,359.2 Annualized Growth 51.9% 18.7% 5.5% (2.5%) 4.3% (1.9%) Loans HFI 11,614.3 13,066.1 12,439.4 13,909.4 14,710.5 14,621.8 Annualized Growth 47.3% 12.5% (4.8%) 11.8% 5.8% 3.6% Tota l Deposi ts 11,941.3 14,398.9 15,553.9 15,121.4 15,723.0 15,842.7 Annualized Growth 54.3% 20.6% 8.0% (2.8%) 4.0% 6.5% Tangible Common Equity (1) 1,245.0 1,433.3 1,507.1 1,328.4 1,358.0 1,376.5 Annualized Growth 48.3% 15.1% 5.2% (11.9%) 2.2% 5.7% Captial Ratios (%) TCE / TA (1) 8.98% 8.60% 8.53% 7.72% 7.55% 7.72% Leverage Ratio 9.32% 9.12% 8.80% 9.49% 8.94% 8.76% Tier 1 Capi ta l 10.19% 10.74% 11.52% 10.45% 9.93% 10.03% Tota l Capi ta l 11.83% 13.32% 13.67% 12.35% 11.57% 11.75% CRE Concentration (Bank Level) 374% 319% 325% 386% 411% 401% Loans HFI / Tota l Deposi ts 97.3% 90.8% 80.0% 92.0% 93.6% 92.3% Asset Quality (%) ACL / Loans HFI (2) 0.47% 0.76% 1.28% 1.09% 1.07% 0.99% NPLs / Loans HFI (2) 0.24% 0.44% 0.49% 0.29% 0.37% 0.40% ACL / NPLs 193% 171% 259% 371% 293% 259% NCOs / Average Loans 0.07% 0.05% 0.06% 0.04% 0.01% 0.10% Earnings and Profitability ROAA 1.32% 1.23% 1.21% 1.09% 0.23% (10.55%) Adjusted ROAA (1) 1.51% 1.28% 1.22% 1.16% 0.73% 0.53% ROAE 8.50% 8.26% 8.86% 8.04% 1.83% (87.53%) Adjusted ROAE (1) 9.69% 8.62% 8.91% 8.59% 5.76% 4.41% ROATCE (1) 16.55% 14.93% 15.38% 14.23% 3.30% (146.65%) Adjusted ROATCE (1) 18.85% 15.58% 15.46% 15.20% 10.37% 7.40% Efficiency Ratio 53.01% 48.79% 51.30% 56.82% 86.44% 509.32% Adjusted Efficiency Ratio (1) 45.95% 46.04% 51.04% 54.20% 63.26% 71.09% Yields and Costs (%) Net Interest Margin (FTE) (1) 3.98% 3.57% 3.13% 3.49% 2.76% 2.50% Yield on Loans 5.47% 4.70% 4.38% 4.58% 5.61% 6.03% Yield on Earning Assets 5.11% 4.20% 3.48% 4.06% 5.22% 5.62% Cost of IB Deposi ts 1.48% 0.83% 0.42% 0.78% 3.27% 4.09% Cost of Tota l Deposi ts 1.08% 0.59% 0.29% 0.52% 2.40% 3.22% For the 12 Months Ending December 31, Represents a non-GAAP measure. See Appendix for non-GAAP reconciliation. Loans HFI excludes mortgage warehouse purchase loans.

51 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. HISTORICAL FINANCIALS – SSB For the 3 Months Ending, 2019 2020 2021 2022 2023 6/30/2024 Balance Sheet ($000) Tota l Assets $ 15,921.9 $ 37,789.9 $ 41,838.5 $ 43,918.7 $ 44,902.0 $ 45,494.0 Annualized Growth 8.5% 137.3% 10.7% 5.0% 2.2% 1.2% Loans HFI 11,375.1 24,664.1 23,928.2 30,177.9 32,388.5 $ 33,234.6 Annualized Growth 3.2% 116.8% (3.0%) 26.1% 7.3% 5.4% Tota l Deposi ts 12,177.1 30,693.9 35,054.8 36,350.6 37,048.9 $ 37,098.4 Annualized Growth 4.6% 152.1% 14.2% 3.7% 1.9% 1.0% Tangible Common Equity (1) 1,320.3 2,921.3 3,093.8 3,035.4 3,521.2 $ 3,649.9 Annualized Growth 1.5% 121.3% 5.9% (1.9%) 16.0% 11.8% Captial Ratios (%) TCE / TA (1) 8.88% 8.10% 7.71% 7.25% 8.21% 8.39% Leverage Ratio 9.73% 8.27% 8.08% 8.72% 9.42% 9.7% Tier 1 Capi ta l 12.25% 11.77% 11.76% 10.96% 11.75% 12.1% Tota l Capi ta l 12.78% 14.24% 13.57% 12.97% 14.08% 14.4% CRE Concentration (Bank Level) 225% 237% 244% 249% 237% 231% Loans HFI / Tota l Deposi ts 93.4% 80.4% 68.3% 83.0% 87.4% 89.6% Asset Quality (%) ACL / Loans HFI 0.62% 1.85% 1.26% 1.18% 1.41% 1.42% NPLs / Loans HFI 0.30% 0.43% 0.34% 0.36% 0.56% 0.59% ACL / NPLs 250% 428% 376% 328% 250% 241% NCOs / Average Loans 0.04% 0.01% 0.01% 0.02% 0.08% 0.05% Earnings and Profitability ROAA 1.21% 0.42% 1.19% 1.12% 1.11% 1.17% Adjusted ROAA (1) 1.27% 0.98% 1.34% 1.20% 1.17% 1.22% ROAE 7.89% 3.35% 10.01% 9.84% 9.37% 9.58% Adjusted ROAE (1) 8.28% 7.81% 11.31% 10.59% 9.94% 9.94% ROATCE (1) 15.11% 6.67% 16.64% 17.16% 15.87% 15.49% Adjusted ROATCE (1) 15.82% 14.14% 18.68% 18.40% 16.80% 16.05% Efficiency Ratio 62.52% 67.47% 65.55% 54.21% 55.50% 57.03% Adjusted Efficiency Ratio (1) 60.33% 56.53% 59.88% 52.34% 53.27% 55.52% Yields and Costs (%) Net Interest Margin (FTE) (1) 3.77% 3.26% 2.92% 3.37% 3.63% 3.44% Yield on Loans 4.77% 4.35% 4.08% 4.28% 5.46% 5.82% Yield on Earning Assets 4.40% 3.57% 3.05% 3.50% 4.85% 5.21% Cost of IB Deposi ts 0.76% 0.36% 0.15% 0.16% 1.77% 2.52% Cost of Tota l Deposi ts 0.56% 0.24% 0.10% 0.10% 1.20% 1.80% For the 12 Months Ending December 31, (1) Represents a non-GAAP measure. See Appendix for non-GAAP reconciliation.

NON-GAAP RECONCILIATION – IBTX 52 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. ($ in thousands except per share data) 2019 2020 2021 2022 2023 6/30/2024 Tangible Common Equity Total common stockholders equity $ 2,339,773 $ 2,515,371 $ 2,576,650 $ 2,385,383 $ 2,402,593 $ 1,897,083 Adjustments: Goodwill (994,021) (994,021) (994,021) (994,021) (994,021) (476,021) Other Intangible Assets, net (100,741) (88,070) (75,490) (62,999) (50,560) (44,532) Tangible Common Equity 1,245,011 1,433,280 1,507,139 1,328,363 1,358,012 1,376,530 Tangible Assets Total Assets 14,958,207 17,753,476 18,732,648 18,258,414 19,035,102 18,359,162 Adjustments: Goodwill (994,021) (994,021) (994,021) (994,021) (994,021) (476,021) Other Intangible Assets, net (100,741) (88,070) (75,490) (62,999) (50,560) (44,532) Tangible Assets 13,863,445 16,671,385 17,663,137 17,201,394 17,990,521 17,838,609 Common Shares Outstanding 42,950,228 43,137,104 42,756,234 41,190,677 41,281,919 41,376,169 Tangible Common Equity to Tangible Assets 8.98% 8.60% 8.53% 7.72% 7.55% 7.72% Book Value Per Common Share $54.48 $58.31 $60.26 $57.91 $58.20 $45.85 Tangible Book Value Per Common Share $28.99 $33.23 $35.25 $32.25 $32.90 $33.27 Return on Average Tangible Common Equity Net Income 192,736 201,209 224,750 196,291 43,201 (493,455) Average shareholders' common equity 2,267,103 2,435,474 2,536,658 2,442,315 2,361,267 2,267,289 (Less) Average intangible assets 1,102,188 1,087,890 1,075,258 1,062,712 1,050,267 913,976 Average Tangible Common Equity 1,164,915 1,347,584 1,461,400 1,379,603 1,311,000 1,353,313 Return on Average Tangible Common Equity 16.55% 14.93% 15.38% 14.23% 3.30% (146.65%) For the 3 Months Ending, For the 12 Months Ending December 31,

NON-GAAP RECONCILIATION – IBTX (CONTINUED) This is not applicable starting in 2021 under the adoption of CECL.. Separation expense include severance and accelerated vesting expense for stock awards related to the separation of certain employees. The year ended December 31, 2022 reflects a reduction in workforce due to the restructuring of certain departments and business lines, payments made due to the separation of executive officers and payments made related to the dissolution of a Company department. COVID-19 expense includes expenses for COVID testing kits, vaccination incentive bonuses, and personal protection and cleaning supplies. Acquisition expenses includes all merger related expenses. Assumes an adjusted effective tax rate of 21.0%, 20.5%, 20.4%, 20.3%, 20.2%, and 20.5%, respectively. Excludes average balance of goodwill and net other intangible assets and preferred stock. Calculated using adjusted net income. For the 3 Months Ending, ($ in thousands except per share data) 2019 2022 2023 6/30/2024 Net Interest Income - Reported (a) $ 504,757 $ For the 12 Months Ending December 31, 2020 2021 516,446 $ 520,322 $ 558,208 $ 105,148 456,883 $ Unexpected income recognized on credit impaired acquired loans(1) (5,120) (3,209) - - - - Adjusted Net Interest Income (b) 499,637 513,237 520,322 558,208 456,883 105,148 Provision Expense - Reported (c) 14,805 42,993 (9,000) 4,490 4,130 - Noninterest Income - Reported (d) 78,176 85,063 66,517 51,466 51,109 13,433 Gain (loss) on sale of loans (6,779) (356) (56) 1,844 14 - Gain on sale of branch (1,549) - - - - - Gain on sale of trust business (1,319) - - - - - Gain (loss) on sale of other real estate (875) 36 (63) - 1,797 Gain on sale of securities available for sale (275) (382) (13) - - Loss (Gain) on sale and disposal of premises and equipment 585 (370) 304 494 (323) 11 Recoveries on loans charged off prior to acquisition (2,101) (4,312) (381) (192) (473) (57) Adjusted Noninterest Income (e) 65,863 79,679 66,308 53,612 52,124 13,387 Noninterest Expense - Reported (f) 321,864 306,134 313,606 358,889 451,544 606,911 Separation expense(2) (3,421) - - (11,046) - - Litigation settlement - - - - (102,500) - Economic development employee incentive grant - - - 1,000 - - OREO impairment (1,801) (784) - - (5,215) - FDIC special assessment - - - - (8,329) 645 Goodwill and asset impairment (1,173) (462) (124) (4,442) (955) (518,000) COVID-19 expense(3) - (1,915) (614) - - Acquisition expense(4) (42,744) (17,294) (900) (300) (107) (2,338) Adjusted Noninterest Expense (g) 272,725 285,679 311,968 344,101 334,438 87,218 Income Tax Expense - Reported (h) 53,528 51,173 57,483 50,004 9,117 5,125 Net Income - Reported (a) - (c) + (d) - (f) - (h) = (i) 192,736 201,209 224,750 196,291 43,201 (493,455) Adjusted Net Income(5) (b) - (c) + (e) - (g) = (j) 219,582 210,017 225,893 209,747 135,942 24,884 EFFICIENCY RATIO Amortization of other intangible assets (k) 12,880 12,671 $12,580 $12,491 $12,439 $2,953 Reported Efficiency Ratio (f - k) / (a + d) 53.01% 48.79% 51.30% 56.82% 86.44% 509.32% Adjusted Efficiency Ratio (g - k) / (b + e) 45.95% 46.04% 51.04% 54.20% 63.26% 71.09% NONINTEREST EXPENSE / AVERAGE ASSETS Reported Noninterest Expense / Average Assets (f) / (l) 2.21% 1.87% 1.69% 1.99% 2.43% 12.98% Adjusted Noninterest Expense / Average Assets (g) / (l) 1.87% 1.75% 1.68% 1.91% 1.80% 1.87% NONINTEREST INCOME / TOTAL REVENUE Reported Noninterest Income / Total Revenue d / (a + d) 13.4% 14.1% 11.3% 8.4% 10.1% 11.3% Adjusted Noninterest Income / Adjusted Total Revenue e / (b + e) 11.6% 13.4% 11.3% 8.8% 10.2% 11.3% PROFITABILITY Total Average Assets (l) 14,555,315 16,357,736 18,558,168 18,009,090 18,555,748 18,803,877 Total Average Stockholders Common Equity (m) 2,267,103 2,435,474 2,536,658 2,442,315 2,361,267 2,267,289 Total Average Tangible Common Equity(6) (n) 1,164,915 1,347,584 1,461,400 1,379,603 1,311,000 1,353,313 Reported Return on Average Assets Reported Return on Average Common Equity Reported Return on Average Tangible Common Equity (i) / (l) (i) / (m) (i) / (n) 1.32% 8.50% 16.55% 1.23% 8.26% 14.93% 1.21% 8.86% 15.38% 1.09% 8.04% 14.23% 0.23% 1.83% 3.30% (10.55%) (87.53%) (146.65%) Adjusted Return on Average Assets(7) (j) / (l) 1.51% 1.28% 1.22% 1.16% 0.73% 0.53% Adjusted Return on Average Common Equity(7) (j) / (m) 9.69% 8.62% 8.91% 8.59% 5.76% 4.41% Adjusted Return on Average Tangible Common Equity(7) (j) / (n) 18.85% 15.58% 15.46% 15.20% 10.37% 7.40% 53 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER.

NON-GAAP RECONCILIATION – IBTX (CONTINUED) 54 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. 2019 2020 2021 2022 2023 6/30/2024 NET INTEREST MARGIN Net Interest Income - Reported (a) $ 504,757 $ 516,446 $ 520,322 $ 558,208 $ 456,883 $ 105,148 Tax equivalent adjustments 3,741 3,828 3,938 4,425 4,173 1,075 Net Interest Income - Tax Equivalent (o) 508,498 520,274 524,260 562,633 461,056 106,223 Average Earning Assets (p) 12,784,084 14,565,011 16,757,867 16,116,535 16,696,195 17,095,551 Net Interest Margin - Reported (a) / (p) 3.95% 3.55% 3.10% 3.46% 2.74% 2.47% Net Interest Margin - Tax Equivalent (a) / (o) 3.98% 3.57% 3.13% 3.49% 2.76% 2.50% For the 3 Months Ending, For the 12 Months Ending December 31,

NON-GAAP RECONCILIATION – SSB ($ in thousands except per share data) For the 12 Months Ending December 31, 2019 2020 2021 2022 2023 For the 3 Months Ending, 6/30/2024 Tangible Common Equity Total common stockholders equity $ 2,373,013 $ 4,647,880 $ 4,802,940 $ 5,074,927 $ 5,533,098 $ 5,650,402 Adjustments: Goodwill (1,002,900) (1,563,942) (1,581,085) (1,923,106) (1,923,106) (1,923,106) Other Intangible Assets, net (49,816) (162,592) (128,067) (116,450) (88,776) (77,389) Tangible Common Equity 1,320,297 2,921,346 3,093,788 3,035,371 3,521,216 3,649,907 Tangible Assets Total Assets 15,921,881 37,789,873 41,838,456 43,918,696 44,902,024 45,493,969 Adjustments: Goodwill (1,002,900) (1,563,942) (1,581,085) (1,923,106) (1,923,106) (1,923,106) Other Intangible Assets, net (49,816) (162,592) (128,067) (116,450) (88,776) (77,389) Tangible Assets 14,869,165 36,063,339 40,129,304 41,879,140 42,890,142 43,493,474 Common Shares Outstanding 33,744,385 70,973,477 69,332,297 75,704,563 76,022,039 76,195,723 Tangible Common Equity to Tangible Assets 8.88% 8.10% 7.71% 7.25% 8.21% 8.39% Book Value Per Common Share $70.32 $65.49 $69.27 $67.04 $72.78 $74.16 Tangible Book Value Per Common Share $39.13 $41.16 $44.62 $40.09 $46.32 $47.90 Return on Average Tangible Common Equity Net Income 186,483 120,632 475,543 496,049 494,308 132,370 (Plus) Amortization of intangibles, net of taxes 10,589 23,148 27,696 26,006 21,594 4,399 Net income plus after-tax amortization of intangibles 197,072 143,780 503,239 522,055 515,902 136,769 Average shareholders' common equity 2,363,652 3,605,416 4,748,926 5,040,281 5,277,366 5,554,470 (Less) Average intangible assets (1,059,435) (1,449,256) (1,725,164) (1,997,915) (2,026,167) (2,003,930) Average Tangible Common Equity 1,304,217 2,156,160 3,023,762 3,042,366 3,251,199 3,550,540 Return on Average Tangible Common Equity 15.11% 6.67% 16.64% 17.16% 15.87% 15.49% 55 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER.

NON-GAAP RECONCILIATION – SSB (CONTINUED) 56 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. For the 3 Months Ending, For the 12 Months Ending December 31, ($ in thousands except per share data) 2019 2020 2021 2022 2023 6/30/2024 Adjusted Net Income Net Income (GAAP) $ 186,483 $ 120,632 $ 475,543 $ 496,049 $ 494,308 $ 132,370 Securities losses (gains), net of tax (2,173) (41) (81) (24) (33) - PCL - non PCD loans and UFC, net of tax - 92,212 - 13,492 - - Pension plan termination expense, net of tax 7,641 - - - - - Swap termination expense, net of tax - 31,784 - - - - Provision (Benefit) for income taxes - carryback tax loss - (31,468) - - - - FHLB prepayment penalty, net of tax 107 200 - - - - Merger, branch consolidation and severance related expense, net of tax 3,701 68,369 52,740 24,163 10,291 4,430 Extinguishment of debt cost, net of tax - - 9,081 - - - FDIC special assessment, net of tax - - - - 20,087 474 Adjusted Net Income (non-GAAP) 195,759 281,688 537,283 533,680 524,653 137,274 Adjusted Return on Average Assets Return on Average Assets (GAAP) 1.21% 0.42% 1.19% 1.12% 1.11% 1.17% Effect to adjust for securities losses (gains), net of tax (0.01%) (0.00%) (0.00%) (0.00%) (0.00%) - Effect to adjust for PCL - non PCD loans and UFC, net of tax 0.00% 0.32% - 0.03% - - Effect to adjust for pension plan termination expense, net of tax 0.05% - - - - - Effect to adjust for swap termination expense, net of tax - 0.12% - - - - Effect to adjust for benefit for income taxes - carryback tax loss - (0.11%) - - - - Effect to adjust for FHLB prepayment penalty, net of tax 0.00% 0.00% - - - - Effect to adjust for merger, branch consolidation and severance related expense, net of tax 0.02% 0.23% 0.13% 0.05% 0.02% 0.05% Effect to adjust for extinguishment of debt cost, net of tax - - 0.02% - - - Effect to adjust for FDIC special assessment, net of tax - - - - 0.04% 0.00% Adjusted Return on Average Assets (non-GAAP) 1.27% 0.98% 1.34% 1.20% 1.17% 1.22%

NON-GAAP RECONCILIATION – SSB (CONTINUED) 57 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. ($ in thousands except per share data) 2019 2020 2021 2022 2023 6/30/2024 Adjusted Return on Average Common Equity Return on Average Common Equity (GAAP) 7.89% 3.35% 10.01% 9.84% 9.37% 9.58% Effect to adjust for securities losses (gains), net of tax (0.09%) (0.00%) (0.00%) (0.00%) (0.00%) - Effect to adjust for PCL - non PCD loans and UFC, net of tax 0.00% 2.56% - 0.27% - - Effect to adjust for pension plan termination expense, net of tax 0.32% - - - - - Effect to adjust for swap termination expense, net of tax - 0.88% - - - - Effect to adjust for benefit for income taxes - carryback tax loss - (0.87%) - - - - Effect to adjust for FHLB prepayment penalty, net of tax 0.01% 0.01% - - - - Effect to adjust for merger, branch consolidation and severance related expense, net of tax 0.15% 1.88% 1.11% 0.48% 0.19% 0.33% Effect to adjust for extinguishment of debt cost, net of tax - - 0.19% - - - Effect to adjust for FDIC special assessment, net of tax - - - - 0.38% 0.03% Adjusted Return on Average Common Equity (non-GAAP) 8.28% 7.81% 11.31% 10.59% 9.94% 9.94% Adjusted Return on Average Tangible Common Equity Return on Average Common Equity (GAAP) 7.89% 3.35% 10.01% 9.84% 9.37% 9.58% Effect to adjust for securities losses (gains), net of tax (0.09%) (0.00%) (0.00%) (0.00%) (0.00%) - Effect to adjust for PCL - non PCD loans and UFC, net of tax 0.00% 2.56% - 0.27% - - Effect to adjust for pension plan termination expense, net of tax 0.32% - - - - - Effect to adjust for swap termination expense, net of tax - 3.51% - - - - Effect to adjust for benefit for income taxes - carryback tax loss - (0.87%) - - - - Effect to adjust for FHLB prepayment penalty, net of tax 0.00% 0.01% - - - - Effect to adjust for merger, branch consolidation and severance related expense, net of tax 0.16% 1.90% 1.11% 0.48% 0.20% 0.32% Effect to adjust for extinguishment of debt cost, net of tax - - 0.19% - - - Effect to adjust for FDIC special assessment, net of tax - - - - 0.38% 0.03% Effect to adjust for intangible assets, net of tax 7.54% 3.68% 7.37% 7.81% 6.85% 6.12% Adjusted Return on Average Tangible Common Equity (non-GAAP) 15.82% 14.14% 18.68% 18.40% 16.80% 16.05% For the 3 Months Ending, For the 12 Months Ending December 31,

NON-GAAP RECONCILIATION – SSB (CONTINUED) 58 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. ($ in thousands except per share data) 2019 2020 2021 2022 2023 6/30/2024 Adjusted Efficiency Ratio Efficiency Ratio 62.52% 67.47% 65.55% 54.21% 55.50% 57.03% Effect to adjust for swap termination expense - (3.40%) - - - - Effect to adjust for merger, branch consolidation and severance related expense (0.70%) (7.54%) (5.67%) (1.87%) (0.76%) (1.36%) Effect to adjust for pension plan termination expense (1.47%) - - - - - Effect to adjust for FHLB prepayment penalty (0.02%) - - - - - Effect to adjust for FDIC special assessment - - - - (1.47%) (0.15%) Adjusted Efficiency Ratio 60.33% 56.53% 59.88% 52.34% 53.27% 55.52% Net Interest Margin - Tax Equivalent Net interest income $ 504,275 $ 826,465 $ 1,033,175 $ 1,335,671 $ 1,452,608 $ 350,259 Tax equivalent adjustments 2,072 4,592 5,921 8,876 3,023 631 Net interest income (tax equivalent) 506,347 831,057 1,039,096 1,344,547 1,455,631 350,890 Average interest earnings assets 13,416,147 25,460,624 35,620,647 39,881,909 40,098,398 41,011,662 Net Interest Margin (GAAP) 3.76% 3.25% 2.90% 3.35% 3.62% 3.43% Net Interest Margin (Tax Equivalent) 3.77% 3.26% 2.92% 3.37% 3.63% 3.44% Adjusted Noninterest Expense / Average Assets Noninterest Expense $ 404,638 $ 797,644 $ 948,421 $ 929,701 $ 994,580 $ 248,747 Pension plan termination expense (9,526) - - - - - Swap termination expense - (38,787) - - - - Merger, branch consolidation, severance related and other expense (4,552) (85,906) (67,242) (30,888) (13,162) (5,785) Extinguishment of debt costs - - (11,706) - - - FDIC special assessment - - - - (25,691) (619) Adjusted Noninterest Expense 390,560 672,951 869,473 898,813 955,727 242,343 Average Assets 15,428,827 28,761,512 39,847,686 44,480,475 44,655,961 $ 45,427,734 Noninterest Expense / Average Assets 2.62% 2.77% 2.38% 2.09% 2.23% 2.20% Adjusted Noninterest Expense / Average Assets 2.53% 2.34% 2.18% 2.02% 2.14% 2.15% For the 3 Months Ending, For the 12 Months Ending December 31,

NON-GAAP RECONCILIATION – SSB (CONTINUED) 59 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. ($ in thousands except per share data) 2019 2020 2021 2022 2023 6/30/2024 Adjusted Noninterest Income / Adjusted Total Revenue Net Interest Income (a) $ 504,275 $ 826,465 $ 1,033,175 $ 1,335,671 $ 1,452,608 $ 350,259 Noninterest Income (b) $ 143,565 $ 311,140 $ 354,252 $ 309,247 $ 286,906 $ 75,225 Securities losses (gains) (2,711) (50) (102) (30) (43) $ - Adjusted Noninterest Income (c) 140,854 311,090 354,150 309,217 286,863 75,225 Noninterest Income / Total Revenue (b) / (a + b) 22.2% 27.4% 25.5% 18.8% 16.5% 17.7% Adjusted Noninterest Income / Adjusted Total Revenue (c) / (a + c) 21.8% 27.3% 25.5% 18.8% 16.5% 17.7% For the 3 Months Ending, For the 12 Months Ending December 31,

60 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. NON-GAAP RECONCILIATION – ILLUSTRATIVE COMBINED COMPANY EARNINGS ACCRETION Note: The information presented on this slide reflects expectations regarding the combined company and is inclusive of the assumptions detailed on slide 11. (1) For illustrative purposes, assumes merger with SSB closes on 1/1/2025, cost savings are fully phased-in and excludes one- time deal costs. Dollars in millions; excluding per share data Stated Excluding Rate Marks/ CDI Excluding Rate Marks/ CDI/CECL SSB Earnings (Mean Consensus Estimates GAAP) $526.9 $526.9 $526.9 IBTX Earnings (Mean Consensus Estimates GAAP) 167.0 $167.0 $167.0 Combined Earnings $693.9 $693.9 $693.9 Run-Rate Cost Savings $70.5 $70.5 $70.5 Accretion of Interest Rate Marks 97.8 - - Accretion Non-PCD Credit Mark 27.3 27.3 - Incremental Income on Loan / Securities Portfolio Sale and Securities Reinvestment 33.0 33.0 33.0 Amortization of Core Deposit Intangible (49.3) - - Other Adjustments(2) 16.0 16.0 16.0 Pro Forma Earnings $889.2 $840.7 $813.4 Standalone Avg. Diluted Shares Outstanding (Millions) 76.6 76.6 76.6 Standalone EPS $6.88 $6.88 $6.88 Pro Forma Avg. Diluted Shares Outstanding (Millions) 101.5 101.5 101.5 Pro Forma EPS $8.76 $8.29 $8.02 EPS Accretion ($) $1.88 $1.40 $1.13 EPS Accretion (%) 27.3% 20.4% 16.5% For the Year Ending December 31, 2025 (1)

61 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. NON-GAAP RECONCILIATION – ILLUSTRATIVE COMBINED COMPANY TBV DILUTION Stated Excluding Rate Marks / CDI Excluding Rate Marks / CDI / CECL $ Millions Millions of Shares $ Per Share $ Millions Millions of Shares $ Per Share $ Millions Millions of Shares $ Per Share SSB Tangible Book Value at Close (3/31/2025) Equity Consideration to IBTX Core Deposit Intangibles Goodwill Created Restructuring Cost Attributable to SSB Establishment of Day 2 Non-PCD Reserve $50.95 76.2 24.9 $3,881.5 2,024.5 (342.9) (716.8) (104.9) (81.8) $50.95 76.2 24.9 $3,881.5 2,024.5 0.0 (668.8) (104.9) (81.8) $50.95 76.2 24.9 $3,881.5 2,024.5 0.0 (668.8) (104.9) 0.0 Pro Forma Tangible Book Value $4,659.7 101.1 $46.08 $5,050.6 101.1 $49.95 $5,132.3 101.1 $50.76 SSB Tangible Book Value Per Share Accretion / (Dilution) ($) SSB Tangible Book Value Per Share Accretion / (Dilution) (%) TBVPS Earnback (years) ($4.87) (9.6%) 2.0 ($1.01) (2.0%) 0.9 ($0.20) (0.4%) 0.3 Note: The information presented on this slide reflects expectations regarding the combined company and is inclusive of the assumptions detailed on slide 11.

62 GROWTH MARKETS. COMMON CULTURE. BETTER TOGETHER. NON-GAAP RECONCILIATION – ILLUSTRATIVE COMBINED COMPANY RETURN ON TCE Dollars in millions; excluding per share data For the Year Ended 12/31/2025 (1) SSB Earnings (Mean Consensus Estimates GAAP) $526.9 IBTX Earnings (Mean Consensus Estimates GAAP) 167.0 Combined Earnings $693.9 Run-Rate Cost Savings $70.5 Accretion of Interest Rate Marks 97.8 Accretion Non-PCD Credit Mark 27.3 Incremental Income on Loan / Securities Portfolio Sale and Securities Reinvestment 33.0 Amortization of Core Deposit Intangible (49.3) Other Adjustments(2) 16.0 Pro Forma Earnings $889.2 Average Common Equity 7,955.8 Average Intangibles 3,014.1 Average Tangible Common Equity 4,941.7 Return on Average Tangible Common Equity 18.0% Note: The information presented on this slide reflects expectations regarding the combined company and is inclusive of the assumptions detailed on slide 11. (1) For illustrative purposes, assumes merger with SSB closes on 1/1/2025, cost savings are fully phased-in and excludes one- time deal costs.