Acquisition of Guaranty BancorpNasdaq: GBNKMay 22, 2018 Exhibit 99.1Independent Bank Group

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Certain statements contained in this communication that are not statements of historical fact constitute forward-looking statements within the meaning of the PrivateSecurities 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 theSecurities Act of 1993, as amended and Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements include informationabout Independent Bank Group’s and Guaranty Bancorp’s possible or assumed future economic performance or future results of operations, including IndependentBank Group’s or Guaranty Bancorp’s future revenues, income, expenses, provision for loan losses, provision for taxes, effective tax rate, earnings per share and cashflows, and Independent Bank Group’s and Guaranty Bancorp’s future capital expenditures and dividends, future financial condition and changes therein, includingchanges in Independent Bank Group’s and Guaranty Bancorp’s loan portfolio and allowance for loan losses, future capital structure or changes therein, as well as theplans and objectives of management for Independent Bank Group’s and Guaranty Bancorp’s future operations, future or proposed acquisitions, the future or expectedeffect of acquisitions on Independent Bank Group’s and Guaranty Bancorp’s operations, results of operations, financial condition, and future economic performance,statements about the benefits of the proposed transaction, and the statements of the assumptions underlying any such statement. Such statements are typically, but notexclusively, identified by the use in the statements of words or phrases such as “aim”, “anticipate”, “estimate”, “expect”, “goal”, “guidance”, “intend”, “isanticipated”, “is expected”, “is intended”, “objective”, “plan”, “projected”, “projection”, “will affect”, “will be”, “will continue”, “will decrease”, “will grow”, “willimpact”, “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 Independent Bank Group and Guaranty Bancorp make are based on our current expectations andassumptions regarding Independent Bank Group’s and Guaranty Bancorp’s businesses, the economy, and other future conditions. Because forward-lookingstatements relate to future results and occurrences, they are subject to inherent uncertainties, risks, and changes in circumstances that are difficult to predict. Manypossible events or factors could affect Independent Bank Group’s or Guaranty Bancorp’s future financial results and performance and could cause those results orperformance to differ materially from those expressed in the forward-looking statements. Such risks and uncertainties include, among others: the occurrence of anyevent, change or other circumstances that could give rise to the right of one or both of the parties to terminate the definitive merger agreement between IndependentBank Group and Guaranty Bancorp, the outcome of any legal proceedings that may be instituted against Independent Bank Group or Guaranty Bancorp, delays incompleting the transaction, the failure to obtain necessary regulatory approvals (and the risk that such approvals may result in the imposition of conditions that couldadversely affect the combined company or the expected benefits of the transaction) and shareholder approvals or to satisfy any of the other conditions to thetransaction on a timely basis or at all, the possibility that the anticipated benefits of the transaction are not realized when expected or at all, including as a result of theimpact of, or problems arising from, the integration of the two companies or as a result of the strength of the economy and competitive factors in the areas whereIndependent Bank Group and Guaranty Bancorp do business, the possibility that the transaction may be more expensive to complete than anticipated, including as aresult of unexpected factors or events, diversion of management’s attention from ongoing business operations and opportunities, potential adverse reactions orchanges to business or employee relationships, including those resulting from the announcement or completion of the transaction, Independent Bank Group’s abilityto complete the acquisition and integration of Guaranty Bancorp successfully, and the dilution caused by Independent Bank Group’s issuance of additional shares ofits common stock in connection with the transaction. Each of Independent Bank Group and Guaranty Bancorp disclaims any obligation to update such factors or topublicly announce the results of any revisions to any of the forward-looking statements included herein to reflect future events or developments. Further informationon Independent Bank Group, Guaranty Bancorp, and factors which could affect the forward-looking statements contained herein can be found in Independent BankGroup’s Annual Report on Form 10-K for the fiscal year ended December 31, 2017, its Quarterly Report on Form 10-Q for the three-month period ended March 31,2018 and its other filings with the Securities and Exchange Commission (“SEC”), and in Guaranty Bancorp’s Annual Report on Form 10-K for the fiscal year endedDecember 31, 2017, its Quarterly Report on Form 10-Q for the three-month period ended March 31, 2018 and its other filings with the SEC.Forward-Looking Statements

Additional Statements
Additional Information about the Merger and Where to Find It
In connection with the proposed acquisition of Guaranty Bancorp, Independent Bank Group will file with the SEC a registration statement on Form S-4 to register the shares of Independent Bank Group’s common stock to be issued in connection with the merger. The registration statement will include a joint proxy statement/prospectus which will be sent to the shareholders of Independent Bank Group and Guaranty Bancorp seeking their approval of the proposed transaction.
WE URGE INVESTORS AND SECURITY HOLDERS TO READ THE REGISTRATION STATEMENT ON FORM S-4, THE JOINT PROXY
STATEMENT/PROSPECTUS INCLUDED WITHIN THE REGISTRATION STATEMENT ON FORM S-4 AND ANY OTHER RELEVANT DOCUMENTS FILED OR TO BE FILED WITH THE SEC IN CONNECTION WITH THE PROPOSED TRANSACTION BECAUSE THESE DOCUMENTS DO AND WILL CONTAIN IMPORTANT INFORMATION ABOUT INDEPENDENT BANK GROUP, GUARANTY BANCORP, AND THE PROPOSED TRANSACTION.
Investors and security holders may obtain copies of these documents free of charge through the website maintained by the SEC at www.sec.gov or from Independent Bank Group at its website, www.ibtx.com, or from Guaranty Bancorp at its website, www.gbnk.com. Documents filed with the SEC by Independent Bank Group will be available free of charge by directing a request by telephone or mail to Independent Bank Group, Inc., 1600 Redbud Blvd., Suite 400, McKinney, Texas 75069, 972-562-9004, and documents filed with the SEC by Guaranty Bancorp will be available free of charge by directing a request by telephone or mail to Guaranty Bancorp, 1331 Seventeenth St., Suite 200, Denver, Colorado 80202, 303-293-5563.
Participants in the Solicitation
Independent Bank Group, Guaranty Bancorp and certain of their respective directors and executive officers may be deemed to be participants in the solicitation of proxies from the shareholders of Independent Bank Group and Guaranty Bancorp in connection with the proposed transaction. Certain information regarding the interests of these participants and a description of their direct and indirect interests, by security holdings or otherwise, will be included in the joint proxy statement/prospectus regarding the proposed transaction when it becomes available. Additional information about Independent Bank Group, and its directors and executive officers, may be found in the definitive proxy statement of Independent Bank Group relating to its 2018 Annual Meeting of Shareholders filed with the SEC on April 26, 2018, and other documents filed by Independent Bank Group with the SEC. Additional information about Guaranty Bancorp, and its directors and executive officers, may be found in the definitive proxy statement of Guaranty Bancorp relating to its 2018 Annual Meeting of Stockholders filed with the SEC on March 23, 2018, and other documents filed by Guaranty Bancorp with the SEC. These documents can be obtained free of charge from the sources described above.
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Overview of Guaranty Bancorp (GBNK)
• Denver, Colorado headquartered bank established in 1955 and Nasdaq listed in 2005, with 32 branches strategically located along the Front Range, including 14 in the Denver MSA
• Largest bank operating exclusively in Colorado and the fourth largest bank headquartered in the state – ranks second in Colorado deposit market share among banks headquartered in the state
• High quality, committed management team and experienced, customer focused lenders
• Strong profitability metrics – core ROAA over 1.20%
• Attractive funding base – over 30% noninterest bearing deposits, with a cost of deposits of approximately 30 basis points
• Conservative credit culture – five year average net charge-offs to average loans from 2013 to 2017 of 0.05% vs. U.S. commercial bank industry aggregate of 0.51%
• Sizable wealth management platform with approximately $1.5 billion in assets under management – provides opportunity for augmentation and scale in Texas metro markets
Financial Summary(1)Balance Sheet DataTotal Assets ($M)    3,721.7 Total Loans Held for Investment ($M)    2,845.5 Total Deposits ($M)    3,031.7 Loans to Deposits (%)                93.9Regulatory CapitalTangible Common Equity ($M)                324.8 Tang. Common Equity / Tang. Assets (%)                8.9 Total Risk Based Capital Ratio (%)                13.3Profitability Data (LTM)Adjusted Net Income ($M)(2)                43.3 Adjusted Return on Average Assets (%)(2)                1.22 Adjusted Return on Average Equity (%)(2)                11.2 Net Interest Margin (%)                3.88 Efficiency Ratio                51.9Asset QualityNonperforming Assets to Assets (%)(3)                0.16 Net Charge-offs to Average Loans (%)                0.04
Source: SNL Financial as of March 31, 2018
(1) Data as of and for the last twelve months ended March 31, 2018
(2) LTM net income reflects adjustment for one-time deferred tax asset revaluation associated with tax legislation of $976 thousand (3) Excludes performing restructured loans
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Transaction SummaryGuaranty Bancorp (“GBNK”) and bank subsidiary,Merger PartnerGuaranty Bank and Trust CompanyTransaction Value(1) $1.0 billion in aggregate, or $35.37 per shareConsideration Mix 100% stock0.45 IBTX common shares for each share of GBNK common stock, which equates to 13,189,494 shares of Fixed Exchange RatioIBTX common stock based on the number of shares of GBNK common stock outstanding as of May 21, 2018Pro Forma Ownership 70% IBTX / 30% GBNKAdditions to Paul Taylor (President & CEO of GBNK) and Ed Cordes (Chairman of GBNK) to join IBTX Board of Directors Management / Board Michael Hobbs (President of Guaranty Bank and Trust Company) to serve as Colorado Market CEO for IBTXRequired Approvals IBTX and GBNK shareholders, as well as customary regulatory approvalsAnticipated Closing Fourth quarter of 2018, subject to regulatory and shareholder approvals and other customary closing conditions(1) Based on an IBTX closing price of $78.60 on May 21, 20185

Significant Scale Along the Front RangePro Forma Colorado Deposit Market Share2017 2017 2017 CO 2017 Deposits Market Rank HQ Institution Branches ($M) S hare (%)1 Wells Fargo & Co.                159    31,779                24.202 * FirstBank Holding Co.                99    14,784                11.263 U.S. Bancorp                155    14,620                11.134 JPM organ Chase & Co.                115    12,878                9.815 BNP Paribas                75                4,539                 3.466 KeyCorp                59                4,196                 3.19Pro Forma                40                3,192                 2.437 * Guaranty Bancorp                32                2,914                 2.228 * Alpine Banks of Colorado                41                2,892                 2.209 Lauritzen Corp.                26                2,694                 2.0510 Zions Bancorp.                38                2,646                 2.0111 Pinnacle Bancorp Inc.                43                2,637                 2.0112 * CoBiz Financial Inc.                11                2,361                 1.8013 BBVA                37                2,356                 1.7914 Bank of America Corp.                11                2,090                 1.5915 * National Bank Holdings Corp.                50                1,909                 1.4532 Independent Bk Group Inc.                8                278                 0.21Top 15 Institutions                951 105,295                80.17 Total For Institutions In Market                1,472 131,337    100.00Pro Forma Colorado FootprintGBNK (32)IBTX (8)Source: SNL FinancialNote: Reflects FDIC deposit data as of June 30, 20176

Attractive Metropolitan Colorado MarketsFive Year Projected Population Growth8.9% 8.1% 7.7% 6.9% 7.1% 6.8% 3.5% Greeley Fort Collins Denver Boulder Colorado Texas Nationwide MSA MSA MSA MSAFive Year Projected Median Household Income Growth16.8% 12.9% 12.2% 9.7% 9.5% 9.5% 8.9% Greeley Fort Collins Denver Boulder Colorado Texas Nationwide MSA MSA MSA MSA• Demographically attractive markets• The Denver MSA is the largest in the state, with a population of approximately 2.9 million– Ranked fourth among “The Best Places for Business and Careers,” according to Forbes– Home to 10 Fortune 500 companies• Greeley was the third fastest growing metropolitan area in the country in 2017, according to the Greeley Economic Development Council• Fort Collins is recognized as the business center of Northern Colorado and hosts manufacturing facilities for major corporations including Anheuser-Bush, Broadcom and Intel• Boulder is recognized as the top city in the U.S. for education according to Forbes, and is home to the University of Colorado’s flagship campus, which enrolls approximately 33 thousand studentsSource: SNL Financial, Forbes, Fortune, Greeley Economic Development Council, Fort Collins Chamber of Commerce7

Transaction Assumptions and ValuationCost Savings 37.5% of GBNK noninterest expense (80% realized in 2019, and 100% thereafter)• $28.5 million mark on gross loans (1.00% of gross loans)Mark-to-Market • $7.0 million mark on held-to-maturity securities – 4.5 year amortizationAdjustments • $8.9 million unrealized loss on available-for-sale securities – 4.5 year amortization• $5.0 million fixed asset write-upCore Deposit Estimated 2.25% of all non-time deposits, 10 year amortizationIntangiblesGBNK Transaction MultiplesValue as of April 27, 2018(1) Current Value(2) Aggregate Value $969.4 M $1.0 B Per Share $33.07 $35.37Price / Tangible Book Value 2.98x 3.19x Price / Est. 2018 Earnings per Share(3) 17.3x 18.5x Price / Est. 2019 Earnings per Share(3) 15.9x 17.0x Price / Est. 2019 EPS w/Synergies (3)(4) 11.1x 11.9x Core Deposit Premium 23.1% 25.5%(1) Based on an IBTX closing price of $73.50 on April 27, 2018, the date the parties entered into a letter of intent (2) Based on an IBTX closing price of $78.60 on May 21, 2018 (3) Based on Wall Street analyst consensus EPS estimates (4) Assumes hypothetical 100% realization of noninterest expense synergies8

Financial Impact of AcquisitionsEstimated Pro Forma Transaction Consequences (1) GBNK Impact2019 EPS Accretion (80% Cost Saves Realization) (%) ~ 5.1% 2020 EPS Accretion (%) ~ 6.5% 2020 EPS Accretion ($) ~ $0.39 Tangible Book Value per Share Accretion / (Dilution) ~ (4.7%) Tangible Book Value per Share Earnback (Years) ~ 3.1IBTX Projected Pro Forma Standalone w/ Integrity w/ GBNKCapital Ratios 3/31/2018 6/30/2018 12/31/2018Tangible Common Equity / Tangible Assets 8.5% 8.5% 8.7% Leverage Ratio 9.2% 9.1% 9.5% Tier 1 Common Risk Based Ratio 9.6% 9.6% 9.8% Tier 1 Risk Based Capital Ratio 10.0% 9.9% 10.3% Total Risk Based Capital Ratio 12.5% 12.1% 12.1%(1) Includes the impact of lost interchange revenue attributable to the Durbin amendment9

Transaction Rationale • Premier Colorado franchise delivers an attractive core deposit base and strong profitability • Financially attractive transaction with EPS accretion of approximately 6.5% Tangible book value earnback of approximately 3 years IBTX remains well capitalized on a pro forma basis • High quality, committed management team and experienced, customer focused lenders • Significant scale in high-growth, metropolitan markets, including the Denver MSA Fill in and expansion of the branch footprint along the Colorado Front Range, with locations in the downtown or central business districts of Denver, Fort Collins, Greeley, Longmont and Boulder Substantially completes our Colorado acquisition strategy • Partnership with the fourth largest bank headquartered in Colorado GBNK is the largest bank operating exclusively in Colorado On a pro forma basis, IBTX will be ranked 7th in Colorado deposit market share, and will be the only Texas or Colorado headquartered bank with top 10 deposit market share in both states • Improves IBTX’s noninterest bearing deposits to deposits, cost of deposits and loan to deposit ratio GBNK noninterest bearing deposits over 30% GBNK cost of deposits of approximately 30 bps 10

History of Growth – Total Assets Guaranty Bancorp Total Assets—$3,722M (Dollars in Millions) Integrity BancsharesOrganic CAGR of ~21% since 2011(1) Total Assets—$761M$15,000Total CAGR of ~46% since 2011(1)$13,294$12,000 Carlile Bancshares $3,722 Live Oak Financial Total Assets—$2,193M Total Assets—$122M BOH Holdings Total Assets—$1,040M $8,684 $761$9,000 Houston City Bancshares Grand Bank I Bank Holding Company Total Assets—$329M Total Assets—$592M Total Assets—$158M $2,193 Community Group Total Assets—$105M $5,853 $6,000 $5,055 Collin Bank $592 $4,133 Total Assets—$173M $1,491 $3,000 $2,164 $1,740 $262 $173 $02012 2013 2014 2015 2016 2017 3/31/18IBTX IPO: 4/3/2013 Annual Acquired Assets Pending Acquisitions Note: Acquired assets excludes impact of purchase accounting (1) CAGR basis of $1.254 billion as of December 31, 2011 Source: SNL Financial 11

Impact of Crossing $10 Billion in Assets• We will cross the $10 billion threshold as a result of the acquisition and it is possible we will cross the threshold organically by the fourth quarter of 2018• We have been proactively planning for this event and continue to invest in the people, processes and systems necessary to operate successfully as a $10+ billion institution• Pro forma for the pending acquisitions of Integrity and GBNK, we estimate annual interchange revenue loss of $5 million attributable to the Durbin amendment• DFAST preparation currently in process with estimated total implementation costs of $2 million, and a total ongoing annual cost of $500,000 to $1 million, assuming no change in current legislation 12

Appendix 13

Guaranty Bancorp Financial Highlights 12/31/14 -For the Years Ended: Quarters Ended: 3/31/18 2014 2015 2016 2017 6/30/2017 9/30/2017 12/31/2017 3/31/2018 CAGR Balance Sheet ($000) Assets                2,124,778                2,368,525     3,366,427                3,698,890                3,403,852                 3,510,046                3,698,890                 3,721,651 18.8% Loans Held for Investment                1,541,434                1,814,536     2,515,009                2,805,663                2,577,585                 2,661,552                2,805,663                 2,845,525 20.8% Deposits                1,685,324                1,801,845     2,699,084                2,941,627                2,763,623                 2,898,060                2,941,627                 3,031,714 19.8% Equity                206,939                221,639                 352,378                404,899                 367,529                375,152                404,899                 410,432 23.5% Tangible Common Equity                199,785                216,466                 280,657                325,352                 297,105                305,400                325,352                 324,824 16.1% Profitability (%) Net Income(1) ($000) 13,512 22,454 24,727 39,600 10,125 10,054 9,581 13,557 Core ROAA(1)(2) 0.76 1.07 1.12 1.31 1.24 1.37 1.37 1.51 Core ROAE(1)(2) 7.6 11.0 11.3 12.1 11.6 12.6 12.4 13.7 Net Interest Margin 3.73 3.74 3.68 3.88 3.82 4.04 3.96 3.72 Cost of Deposits 0.16 0.18 0.23 0.26 0.26 0.27 0.28 0.31 Efficiency Ratio 72.2 60.9 58.0 52.2 53.8 50.3 49.6 53.9 Balance Sheet Ratios (%) Loans / Deposits 91.5 100.7 93.2 95.4 93.3 91.8 95.4 93.9 TCE / TA 9.4 9.2 8.5 9.0 8.9 8.9 9.0 8.9 Leverage Ratio 11.1 10.7 9.8 10.2 10.0 10.2 10.2 10.0 Tier 1 Risk Based Ratio 12.6 12.1 11.3 11.4 11.5 11.4 11.4 11.3 Total Risk-Based Capital Ratio 13.9 13.2 13.6 13.4 13.7 13.5 13.4 13.3 Asset Quality (%)NPAs / Assets(3) 0.67 0.61 0.16 0.14 0.13 0.12 0.14 0.16 LLR / Loans 1.46 1.27 0.92 0.83 0.90 0.86 0.83 0.82 LLR / NPAs(3) 157 158 435 456 542 543 456 401 NCOs/Avg Loans (0.10) (0.03) (0.01) 0.04 0.04 0.11 (0.01) 0.01 Per Share Information Tangible Book Value per Share ($) 9.24 9.97 9.91 11.13 10.46 10.75 11.13 11.09 Dividends Declared ($) 0.20 0.40 0.46 0.50 0.13 0.13 0.13 0.16 Earnings per Share(1) ($) 0.64 1.06 1.05 1.40 0.36 0.36 0.33 0.47(1) Year and quarter end net income and earnings per share as of 12/31/17 reflects adjustment for one-time deferred tax asset revaluation associated with tax legislation of $976 thousand and $0.03, respectively (2) Excludes (gains)/losses on sale of securities, OREO and other one-time items per SNL Financial (3) Excludes performing restructured loans 14 Source: SNL Financial

Independent Bank Group Financial Highlights 12/31/14 -For the Years Ended: Quarters Ended: 3/31/18 2014 2015 2016 2017 6/30/2017 9/30/2017 12/31/2017 3/31/2018 CAGR Balance Sheet ($000) Assets                4,132,639                5,055,000     5,852,801                8,684,463                8,593,979                 8,891,114                8,684,463                 8,811,014 26.2% Loans Held for Investment                3,200,597                3,987,852     4,570,654                6,471,675                6,236,859                 6,362,315                6,471,675                 6,649,580 25.2% Deposits                3,249,598                4,028,279     4,577,109                6,632,822                6,669,288                 6,872,631                6,632,822                 6,794,660 25.5% Equity                540,851                627,309                 672,365                1,336,018                 1,259,592                1,281,460                1,336,018                 1,354,699 32.7% Tangible Common Equity                275,001                328,371                 399,869                671,316                 603,337                627,561                671,316                 691,328 32.8% Profitability (%)Net Income(1) ($000) 28,978 38,786 53,540 82,040 18,134 23,514 24,721 28,964 Core ROAA(1)(2) 1.06 0.96 1.07 1.18 1.12 1.21 1.28 1.41 Core ROAE(1)(2) 8.1 7.5 9.2 8.3 7.6 8.3 8.5 9.1 Net Interest M argin 4.19 4.05 3.81 3.84 3.80 3.88 4.00 3.97 Cost of Deposits 0.37 0.34 0.38 0.46 0.42 0.48 0.50 0.59 Efficiency Ratio 56.4 57.4 52.0 50.4 52.7 49.9 48.1 50.5 Balance Sheet Ratios (%) Loans / Deposits 98.5 99.0 99.9 97.6 93.5 92.6 97.6 97.9 TCE / TA 7.1 6.9 7.2 8.4 7.6 7.6 8.4 8.5 Leverage Ratio 8.2 8.3 7.8 8.9 8.2 8.3 8.9 9.2 Tier 1 Risk Based Ratio 9.8 8.9 8.6 10.1 9.5 9.6 10.1 10.0 Total Risk-Based Capital Ratio 12.6 11.1 11.4 12.6 11.6 11.7 12.6 12.5 Asset Quality (%)NPAs / Assets(3) 0.20 0.24 0.30 0.25 0.28 0.26 0.25 0.22 LLR / Loans 0.58 0.68 0.69 0.61 0.58 0.59 0.61 0.63 LLR / NPAs(3) 219 225 179 185 149 165 185 212 NCOs/Avg Loans 0.03 0.02 0.12 0.01 0.00 (0.00) 0.02 0.01 Per Share Information Tangible Book Value per Share ($) 16.15 17.85 21.19 23.76 21.71 22.57 23.76 24.37 Dividends Declared ($) 0.24 0.32 0.34 0.40 0.10 0.10 0.10 0.12 Earnings per Share(1) ($) 1.89 2.27 2.93 3.22 0.66 0.85 0.88 1.03(1) Net income and earnings per share for the year and quarter ended 12/31/17 reflects adjustment for one-time deferred tax asset revaluation associated with tax legislation of $5.5 million, $0.22, and $0.20, respectively (2) Excludes (gains)/losses on sale of securities, OREO and other one-time items per SNL Financial (3) Excludes performing restructured loans 15 Source: SNL Financial

Pro Forma Loan Portfolio IBTX Integrity Bancshares Guaranty Bancorp Pro Forma Cons. & Cons. & Cons. & Cons. & Other Other Other Resi. RE Other Resi. REC&I 4.2% 8.5% Resi. RE 6.0% Resi. RE14.1% 13.8% 9.5% C&I12.0% C&I 17.2% 14.7%12.5%12.0% Owner Occ. Owner Const. Owner Owner CRE Occ. Const. C&I & Land Occ. Const. Occ. 19.6% CRE& Land 19.9% 4.9% CRE & LandCRE 16.8%16.3% 13.9% 12.9%17.7%Const. Non Owner Non Owner & Land Non Owner Non Owner Occ. & Multi Occ. & Multi 13.4% Occ. & Multi Occ. & Multi 35.6% 23.8% 43.6%37.0% Loans ($M) Loans ($M) Loans ($M) Loans ($M)Residential RE $                944 14.1% Residential RE $                65 9.5% Residential RE $                490 17.2% Residential RE $    1,499 14.7% Owner Occupied CRE                1,184 17.7% Owner Occupied CRE                134 19.6% Owner Occupied CRE                396 13.9% Owner Occupied CRE                1,714 16.8% Non Owner Occ. & Multi                2,378 35.6% Non Owner Occ. & Multi                163 23.8% Non Owner Occ. & Multi                1,240 43.6% Non Owner Occ. & Multi                3,780 37.0% Construction & Land                1,091 16.3% Construction & Land                92 13.4% Construction & Land                139 4.9% Construction & Land                1,322 12.9% C&I                801 12.0% C&I                136 19.9% C&I                342 12.0% C&I                1,278 12.5% Consumer & Other                280 4.2% Consumer & Other                94 13.8% Consumer & Other                241 8.5% Consumer & Other                615 6.0% Total $    6,678 100.0% Total $                683 100.0% Total $    2,847 100.0% Total $ 10,208 100.0% Yield on loans: 5.09% Yield on loans: 5.51% Yield on loans: 4.53% Yield on loans: 4.96%Note: Data represented by 2018Q1 regulatory data Source: SNL Financial 16

Pro Forma Deposit Composition IBTX Integrity Bancshares Guaranty Bancorp Pro Forma Jumbo Jumbo Jumbo Jumbo Retail CDs NIB Retail CDs Retail CDs Retail CDsCDs 6.2% Demand CDs 4.0% CDs 2.8% CDs 5.1% NIB 6.5% 9.9% 12.6% 8.5% Demand 27.0% NIB NIB Demand 29.5% Demand 32.1%44.9% Savings & MMDA NOW & Savings & 28.6% Other Trans. Savings & MMDA NOW & Savings & 3.4% MMDA NOW & 37.5% NOW & MMDA 40.3% Other Trans. Other Trans. Other Trans. 49.1% 16.6%22.8% 12.7% Deposits ($M) Deposits ($M) Deposits ($M) Deposits ($M) NIB Demand $    1,837 27.0% NIB Demand $                270 44.9% NIB Demand $                973 32.1% NIB Demand $    3,080 29.5% NOW & Other Trans.                1,548 22.8% NOW & Other Trans.                76 12.7% NOW & Other Trans.                104 3.4% NOW & Other Trans.                1,728 16.6% Savings & MMDA                2,545 37.5% Savings & MMDA                172 28.6% Savings & MMDA                1,488 49.1% Savings & MMDA                4,204 40.3% Retail CDs                445 6.5% Retail CDs                59 9.9% Retail CDs                383 12.6% Retail CDs                887 8.5% Jumbo CDs                420 6.2% Jumbo CDs                24 4.0% Jumbo CDs                84 2.8% Jumbo CDs                528 5.1% Total $    6,795 100.0% Total $                601 100.0% Total $    3,032 100.0% Total $ 10,428 100.0% Cost of deposits: 0.58% Cost of deposits: 0.63% Cost of deposits: 0.31% Cost of deposits: 0.51% Yield/Cost Spread: 4.51% Yield/Cost Spread: 4.88% Yield/Cost Spread: 4.22% Yield/Cost Spread: 4.46% Loans / Deposits: 98.3% Loans / Deposits: 113.6% Loans / Deposits: 93.9% Loans / Deposits: 97.9% Note: Data represented by 2018Q1 regulatory data Note: Noninterest bearing deposits include reclassed demand deposits Source: SNL Financial 17

Contact Information Corporate Headquarters Independent Bank Group, Inc. 1600 Redbud Blvd. Suite 400 McKinney, Texas 75069(972) 562-9004 Telephone (972) 562-7734 Faxwww.ibtx.comAnalysts / Investors: Michelle Hickox Executive Vice President and Chief Financial Officer (972) 562-9004 mhickox@ibtx.comMark Haynie Executive Vice President and General Counsel (972) 562-9004 mhaynie@ibtx.com Media: Peggy Smolen Director of Marketing (972) 562-9004 psmolen@ibtx.com18

Independent Bank Group