Exhibit 99.1

FOR IMMEDIATE RELEASE

PROSPERITY BANCSHARES, INC.^®

REPORTS FOURTH QUARTER

2019 EARNINGS

HOUSTON, January 29, 2020. Prosperity Bancshares, Inc.^® (NYSE: PB), the parent company of Prosperity Bank^® (collectively, “Prosperity”), reported net income for the quarter ended December 31, 2019 of $86.134 million compared with $83.331 million for the same period in 2018. Net income per diluted common share was $1.01 compared with $1.19 for the same period in 2018. On November 1, 2019, LegacyTexas Financial Group, Inc. (“LegacyTexas”), merged with Prosperity Bancshares and LegacyTexas Bank merged with Prosperity Bank (collectively, the “Merger”).  During the fourth quarter of 2019, Prosperity incurred merger related charges of $46.402 million, or $0.43⁽¹⁾ per diluted common share. Excluding these charges, earnings per diluted common share was $1.44⁽¹⁾ for the fourth quarter of 2019.  Additionally, loans increased 76.6% during the fourth quarter 2019, primarily due to the Merger. Nonperforming assets remain low at 0.25% of fourth quarter average interest-earning assets.

“The combination of LegacyTexas Bank and Prosperity Bank, which was effective November 1, 2019, has been one of the most exciting times in Prosperity’s history. The commonalities, enthusiasm and strengths that both companies offer should not only result in asset growth, but should also enhance customer and associate opportunities, and ultimately increase shareholder value. We are excited about Prosperity’s future opportunities,” said David Zalman, Prosperity’s Chairman and Chief Executive Officer.

“Prosperity Bank has been rated in the Top 10 of Forbes Best Banks in America for the seventh consecutive year, and we are the highest rated Texas-based bank,” continued Zalman.

“Despite oil and gas prices remaining in the $55 to $60 per barrel range, Texas and Oklahoma continue to experience employment and population growth, with many companies moving to these states because of favorable tax environments and business friendly political climates. Consumer sentiment remains strong and the trends suggest a positive start to 2020,” concluded Zalman.

______________

Page 1 of 18

Results of Operations for the Three Months Ended December 31, 2019

Net income was $86.134 million⁽²⁾ for the three months ended December 31, 2019 compared with $83.331 million⁽³⁾ for the same period in 2018 and was impacted by merger related expenses of $46.402 million. Net income per diluted common share was $1.01 for the three months ended December 31, 2019 compared with $1.19 for the same period in 2018 and was also impacted by the merger related expenses. Annualized returns on average assets, average common equity and average tangible common equity for the three months ended December 31, 2019 were 1.19%, 6.33% and 12.50%⁽¹⁾, respectively. Excluding merger related expenses, annualized returns on average assets, average common equity and average tangible common equity for the three months ended December 31, 2019 were 1.69%⁽¹⁾, 9.02%⁽¹⁾ and 17.82%⁽¹⁾, respectively. Prosperity’s efficiency ratio (excluding credit loss provisions, net gains on the sale of assets and securities and taxes) was 58.07%⁽¹⁾ for the three months ended December 31, 2019. Excluding merger related expenses, the efficiency ratio was 40.85%⁽¹⁾ for the three months ended December 31, 2019.

Net interest income before provision for credit losses for the three months ended December 31, 2019 was $232.030 million compared with $157.248 million for the same period in 2018, an increase of $74.782 million or 47.6%. The increase was primarily due to the Merger and the increase in loan discount accretion of $20.839 million. On a linked quarter basis, net interest income before provision for credit losses was $232.030 million compared with $153.990 million for the three months ended September 30, 2019. The increase was primarily due to the Merger and the increase in loan discount accretion of $22.459 million.

The net interest margin on a tax equivalent basis was 3.66% for the three months ended December 31, 2019 compared with 3.15% for the same period in 2018. The change was primarily due to increased interest-earning assets and the $20.839 million increase in loan discount accretion related to the Merger. On a linked quarter basis, the net interest margin on a tax equivalent basis was 3.66% for the three months ended December 31, 2019 compared with 3.16% for the three months ended September 30, 2019. The change was primarily due to increased interest-earning assets and the $22.459 million increase in loan discount accretion related to the Merger.

Noninterest income was $35.506 million for the three months ended December 31, 2019 compared with $29.079 million for the same period in 2018, an increase of $6.427 million or 22.1%. This increase was primarily due to an increase in other noninterest income, mortgage income, nonsufficient funds fees and credit card, debit card and ATM card fees mainly due to the Merger, partially offset by the loss on sale of assets. On a linked quarter basis, noninterest income increased $4.833 million or 15.8% to $35.506 million compared with $30.673 million for the three months ended September 30, 2019, primarily due to the Merger.

Noninterest expense was $156.451 million for the three months ended December 31, 2019 compared with $80.804 million for the same period in 2018, an increase of $75.647 million or 93.6%. On a linked quarter basis, noninterest expense increased $75.752 million or 93.9% to $156.451 million compared with $80.699 million for the three months ended September 30, 2019. Both increases were primarily due to the merger related expenses of $46.402 million and additional expenses related to two months of operations related to the LegacyTexas banking centers and lending function.

Results of Operations for the Year Ended December 31, 2019

Net income was $332.552 million⁽⁴⁾ for the year ended December 31, 2019 compared with $321.812 million⁽⁵⁾ for the same period in 2018, an increase of $10.740 million or 3.3%, and was impacted by merger related expenses of $46.402 million. Net income per diluted common share was $4.52 for the year ended December 31, 2019 compared with $4.61 for the same period in 2018, a decrease of 2.0%, and was also impacted by the merger related expenses. Annualized returns on average assets, average common equity and average tangible common equity for the year ended December 31, 2019 were 1.38%, 7.46% and 14.23%⁽¹⁾, respectively. Excluding merger related expenses, annualized returns on average assets, average common equity and average tangible common equity for the year ended December 31, 2019 were 1.53%⁽¹⁾, 8.28%⁽¹⁾ and 15.80%⁽¹⁾, respectively. Prosperity’s efficiency ratio (excluding credit loss provisions, net gains and losses on the sale of assets and securities and taxes) was 48.25%⁽¹⁾ for the year ended December 31, 2019. Excluding merger related expenses, the efficiency ratio was 42.60%⁽¹⁾ for the year ended December 31, 2019.

Net interest income before provision for credit losses for the year ended December 31, 2019 was $695.769 million compared with $629.593 million for the same period in 2018, an increase of $66.176 million or 10.5%. This change was primarily due to the Merger and the increase in loan discount accretion of $14.136 million.  

The net interest margin on a tax equivalent basis for the year ended December 31, 2019 was 3.32% compared with 3.18% for the same period in 2018. This change was primarily due to increased interest-earning assets related to the Merger and the increase in loan discount accretion of $14.136 million.

______________

Page 2 of 18

Noninterest income was $124.281 million for the year ended December 31, 2019 compared with $116.012 million for the same period in 2018, an increase of $8.269 million or 7.1%. This increase was primarily due to an increase in other noninterest income, mortgage income, nonsufficient funds fees and credit card, debit card and ATM card fees mainly due to the Merger.

Noninterest expense was $396.542 million for the year ended December 31, 2019 compared with $326.220 million for the same period in 2018, an increase of $70.322 million or 21.6%. The change was primarily due to the $46.402 million of merger related expenses and additional expenses related to two months of operations related to the LegacyTexas banking centers and lending function.

Balance Sheet Information

At December 31, 2019, Prosperity had $32.186 billion in total assets, an increase of $9.492 billion or 41.8%, compared with $22.693 billion at December 31, 2018.

Loans at December 31, 2019 were $18.845 billion, an increase of $8.475 billion or 81.7%, compared with $10.370 billion at December 31, 2018. Linked quarter loans increased $8.172 billion or 76.6% from $10.673 billion at September 30, 2019.

As part of its lending activities, Prosperity extends credit to oil and gas production and servicing companies. Oil and gas production loans are loans to companies directly involved in the exploration and or production of oil and gas. Oil and gas servicing loans are loans to companies that provide services for oil and gas production and exploration. At December 31, 2019, oil and gas loans totaled $698.277 million (net of discount) or 3.7% of total loans, of which $401.452 million were production loans and $296.825 million were servicing loans, compared with total oil and gas loans of $372.482 million (net of discount) or 3.6% of total loans at December 31, 2018, of which $114.175 million were production loans and $258.307 million were servicing loans.

Deposits at December 31, 2019 were $24.200 billion, an increase of $6.943 billion or 40.2%, compared with $17.257 billion at December 31, 2018. Linked quarter deposits increased $7.270 billion or 42.9% from $16.930 billion at September 30, 2019.

The table below provides detail on the impact of loans acquired and deposits assumed in the Merger:

Excluding loans acquired in the Merger and new production by the acquired lending operations since November 1, 2019, loans at December 31, 2019 grew $218.671 million or 2.1% compared with December 31, 2018 and decreased $84.361 million or 0.8% compared to September 30, 2019.

Excluding deposits assumed in the Merger and new deposits generated at the acquired banking centers since November 1, 2019, deposits at December 31, 2019 grew $801.628 million or 4.6% compared with December 31, 2018 and grew $1.128 billion or 6.7% compared to September 30, 2019.

Asset Quality

Nonperforming assets totaled $62.943 million or 0.25% of quarterly average interest-earning assets at December 31, 2019, compared with $18.956 million or 0.10% of quarterly average interest-earning assets at December 31, 2018, and $51.157 million or 0.26% of quarterly average interest-earning assets at September 30, 2019. The increase during the fourth quarter 2019 was primarily due to the Merger.

Page 3 of 18

The allowance for credit losses was $87.469 million or 0.46% of total loans at December 31, 2019, $86.440 million or 0.83% of total loans at December 31, 2018 and $87.061 million or 0.82% of total loans at September 30, 2019. Excluding loans acquired that are accounted for under FASB Accounting Standards Codification (“ASC”) Topics 310-20 and 310-30 and Warehouse Purchase Program loans of $1.553 billion, the allowance for credit losses was 0.83%⁽¹⁾ of remaining loans as of December 31, 2019, compared with 0.88%⁽¹⁾ at December 31, 2018 and 0.85%⁽¹⁾ at September 30, 2019.

The provision for credit losses was $1.700 million for the three months ended December 31, 2019 compared with $1.000 million for the three months ended December 31, 2018 and $1.100 million for the three months ended September 30, 2019. The provision for credit losses was $4.300 million for the year ended December 31, 2019 compared with $16.350 million for the year ended December 31, 2018.

Net charge-offs were $1.291 million for the three months ended December 31, 2019 compared with net charge-offs of $556 thousand for the three months ended December 31, 2018 and net charge-offs of $1.046 million for the three months ended September 30, 2019. Net charge-offs were $3.271 million for the year ended December 31, 2019 compared with $13.951 million for the year ended December 31, 2018.

Dividend

Prosperity Bancshares declared a first quarter cash dividend of $0.46 per share to be paid on April 1, 2020 to all shareholders of record as of March 16, 2020.

Merger with LegacyTexas Financial Group, Inc.

On November 1, 2019, Prosperity completed the merger with LegacyTexas and its wholly-owned subsidiary LegacyTexas Bank headquartered in Plano, Texas. LegacyTexas Bank operated 42 locations in 19 North Texas cities in and around the Dallas-Fort Worth area.  

Pursuant to the terms of the merger agreement, Prosperity issued 26,228,148 shares of Prosperity common stock plus $308.585 million in cash for all outstanding shares of LegacyTexas, which resulted in goodwill of $1.323 billion as of December 31, 2019. Additionally, Prosperity recognized $60.058 million of core deposit intangibles as of December 31, 2019. The goodwill balance as of December 31, 2019 does not include subsequent fair value adjustments that are still being finalized.

Conference Call

Prosperity’s management team will host a conference call on Wednesday, January 29, 2020 at 11:30 a.m. Eastern Time (10:30 a.m. Central Time) to discuss Prosperity’s fourth quarter 2019 earnings. Individuals and investment professionals may participate in the call by dialing 877-883-0383 for domestic participants, or 412-902-6506 for international participants. The elite entry number is 2006967.

Alternatively, individuals may listen to the live webcast of the presentation by visiting Prosperity’s website at www.prosperitybankusa.com. The webcast may be accessed from Prosperity’s home page by selecting “Presentations & Calls” from the drop-down menu on the Investor Relations tab and following the instructions.

Non-GAAP Financial Measures

Prosperity’s management uses certain non-GAAP financial measures to evaluate its performance. Specifically, Prosperity reviews tangible book value per share, return on average tangible common equity, tangible equity to tangible assets ratio and the efficiency ratio, excluding net gains and losses on the sale of assets and securities. Further, as a result of acquisitions and the related purchase accounting adjustments, Prosperity uses certain non-GAAP financial measures and ratios that exclude the impact of these items to evaluate its allowance for credit losses to total loans (excluding acquired loans accounted for under ASC Topics 310-20, “Receivables-Nonrefundable Fees and Other Costs” and 310-30, “Receivables-Loans and Debt Securities Acquired with Deteriorated Credit Quality”). Prosperity believes these non-GAAP financial measures provide information useful to investors in understanding Prosperity’s financial results and that their presentation, together with the accompanying reconciliations, provides a more complete understanding of factors and trends affecting Prosperity’s business and allows investors to view performance in a manner similar to management, the entire financial services sector, bank stock analysts and bank regulators. Further, Prosperity believes that these non-GAAP financial measures provide useful information by excluding certain items that may not be indicative of its core operating earnings and business outlook. These non-GAAP financial measures should not be considered a substitute for, nor of greater importance than, GAAP basis financial measures and results; Prosperity strongly encourages investors to review its consolidated financial statements in their entirety and not to rely on any single financial measure. Because non-GAAP financial measures are not standardized, it may not be possible to compare these financial measures with other companies’ non-GAAP financial measures having the same or similar names. Please refer to the “Notes to Selected Financial Data” at the end of this Earnings Release for a reconciliation of these non-GAAP financial measures to the nearest respective GAAP financial measures.

Page 4 of 18

Prosperity Bancshares, Inc. ®

As of December 31, 2019, Prosperity Bancshares, Inc.^® is a $32.2 billion Houston, Texas based regional financial holding company providing personal banking services and investments to consumers and businesses throughout Texas and Oklahoma.  Founded in 1983, Prosperity believes in a community banking philosophy, taking care of customers, businesses and communities in the areas it serves by providing financial solutions to simplify everyday financial needs. In addition to offering traditional deposit and loan products, Prosperity offers digital banking solutions, credit and debit cards, mortgage services, retail brokerage services, trust and wealth management, and cash management.

As of December 31, 2019, Prosperity operated 285 full-service banking locations: 65 in the Houston area, including The Woodlands; 30 in the South Texas area including Corpus Christi and Victoria; 33 in the Dallas/Fort Worth area; 22 in the East Texas area; 29 in the Central Texas area including Austin and San Antonio; 34 in the West Texas area including Lubbock, Midland-Odessa and Abilene; 16 in the Bryan/College Station area; 6 in the Central Oklahoma area; 8 in the Tulsa, Oklahoma area and 42 in the Dallas/Fort Worth area currently doing business as LegacyTexas Bank.

Cautionary Notes on Forward-Looking Statements

“Safe Harbor” Statement under the Private Securities Litigation Reform Act of 1995: This release contains, and the remarks by Prosperity’s management on the conference call may contain, forward-looking statements within the meaning of the federal securities laws, including Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking 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 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. Forward-looking statements include all statements other than statements of historical fact, including forecasts or trends, and are based on current expectations, assumptions, estimates and projections about Prosperity Bancshares and its subsidiaries. These forward-looking statements may include information about Prosperity’s possible or assumed future economic performance or future results of operations, including future revenues, income, expenses, provision for loan losses, provision for taxes, effective tax rate, earnings per share and cash flows and Prosperity’s future capital expenditures and dividends, future financial condition and changes therein, including changes in Prosperity’s loan portfolio and allowance for loan losses, future capital structure or changes therein, as well as the plans and objectives of management for Prosperity’s future operations, future or proposed acquisitions, the future or expected effect of acquisitions on Prosperity’s operations, results of operations, financial condition, and future economic performance, statements about the anticipated benefits of the proposed transaction, and statements about the assumptions underlying any such statement.  These forward‑looking statements are not guarantees of future performance and are subject to risks and uncertainties, many of which are outside of Prosperity’s control, which may cause actual results to differ materially from those expressed or implied by the forward-looking statements.  These risks and uncertainties include but are not limited to whether Prosperity can: successfully identify acquisition targets and integrate the businesses of acquired companies and banks, including LegacyTexas; continue to sustain its current internal growth rate or total growth rate; provide products and services that appeal to its customers; continue to have access to debt and equity capital markets; and achieve its sales objectives.  Other risks include, but are not limited to: the possibility that credit quality could deteriorate; actions of competitors; changes in laws and regulations (including changes in governmental interpretations of regulations and changes in accounting standards); the possibility that the anticipated benefits of an acquisition transaction, including the LegacyTexas transaction, are not realized when expected or at all, including as a result of the impact of, or problems arising from, the integration of two companies or as a result of the strength of the economy and competitive factors generally; a deterioration or downgrade in the credit quality and credit agency ratings of the securities in Prosperity’s securities portfolio; customer and consumer demand, including customer and consumer response to marketing; effectiveness of spending, investments or programs; fluctuations in the cost and availability of supply chain resources; economic conditions, including currency rate, interest rate and commodity price fluctuations; and weather.  These and various other factors are discussed in Prosperity Bancshares’ Annual Report on Form 10-K for the year ended December 31, 2018 and other reports and statements Prosperity Bancshares has filed with the Securities and Exchange Commission (“SEC”). Copies of the SEC filings for Prosperity Bancshares may be downloaded from the Internet at no charge from http://www.prosperitybankusa.com.

Page 5 of 18

 - - -

Page 6 of 18

Prosperity Bancshares, Inc.^®

Financial Highlights (Unaudited)

(In thousands)

(A) Includes $763, $49, $1,611, $895 and $392 in unrealized gains on available for sale securities for the quarterly periods ended December 31, 2019, September 30, 2019, June 30, 2019, March 31, 2019 and December 31, 2018, respectively.

(B) Includes $602, $38, $1,273, $706 and $310 in after-tax unrealized gains on available for sale securities for the quarterly periods ended December 31, 2019, September 30, 2019, June 30, 2019, March 31, 2019 and December 31, 2018, respectively.

Page 7 of 18

Prosperity Bancshares, Inc.^®

Financial Highlights (Unaudited)

(In thousands)

(C) Interest income on securities was reduced by net premium amortization of $8,556, $8,027, $7,607, $6,589 and $7,338 for the three-month periods ended December 31, 2019, September 30, 2019, June 30, 2019, March 31, 2019 and December 31, 2018, respectively, and $30,779 and $31,614 for the years ended December 31, 2019 and December 31, 2018, respectively.

Page 8 of 18

Prosperity Bancshares, Inc. ^®

Financial Highlights (Unaudited)

(Dollars and share amounts in thousands, except per share data and market prices)