Exhibit 99.1

FOR IMMEDIATE RELEASE

PROSPERITY BANCSHARES, INC.^®

REPORTS SECOND QUARTER

2021 EARNINGS

HOUSTON, July 28, 2021. Prosperity Bancshares, Inc.^® (NYSE: PB), the parent company of Prosperity Bank^® (collectively, “Prosperity”), reported net income of $130.6 million for the quarter ended June 30, 2021 compared with $130.9 million for the same period in 2020. Net income per diluted common share was $1.41 for the quarter ended June 30, 2021, unchanged from the same period in 2020, and the annualized return on second quarter average assets was 1.45%. The second quarter of 2020 includes a tax benefit for net operating losses (“NOL”) of $20.1 million, or $0.22⁽¹⁾ per diluted common share, as a result of the enactment of the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”). Additionally, loans, excluding Warehouse Purchase Program and SBA Paycheck Protection Program (“PPP”) loans, increased $148.8 million or 0.9% (3.7% annualized) and deposits increased $347.1 million or 1.2% (4.8% annualized) during the second quarter of 2021. Nonperforming assets remain low at 0.11% of second quarter average interest-earning assets.  

“For the second quarter of 2021, Prosperity had strong earnings, core loan growth, deposit growth, continued sound asset quality, impressive cost controls, a return on average tangible common equity of 17.49% and remains well reserved,” said David Zalman, Prosperity’s Senior Chairman and Chief Executive Officer.  

“Unemployment rates continue to decrease and GDP growth continues at a high level, as forecasted last year with the re-opening of the economy. We are seeing increased oil and gas prices as well as increased farm commodity prices, both of which are positive for the Texas and Oklahoma economies. Further, businesses and individuals continue to move to Texas for lower tax rates and a better quality of life,” continued Zalman.

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“We believe that Prosperity is well positioned to grow along with the Texas and Oklahoma economies. For 2021, Prosperity Bank was ranked the 2nd Best Bank in America by Forbes and has been ranked in the Top 10 of Forbes America’s Best Banks since 2010. We have a deep bench of associates with a passion to help Prosperity and our customers succeed,” concluded Zalman.

Results of Operations for the Three Months Ended June 30, 2021

Net income was $130.6 million⁽²⁾ for the three months ended June 30, 2021 compared with $130.9 million⁽³⁾ for the same period in 2020, a decrease of $290 thousand or 0.2%. Net income per diluted common share was $1.41 for the three months ended June 30, 2021 and 2020. Net income for the second quarter of 2020 includes a tax benefit for NOL of $20.1 million and merger related expenses of $7.5 million. Net income was $130.6 million⁽²⁾ for the three months ended June 30, 2021 compared with $133.3 million⁽⁴⁾ for the three months ended March 31, 2021, a decrease of $2.7 million or 2.0%. The change was primarily due to a decrease in PPP fee income and a decrease in loan discount accretion of $4.1 million, partially offset by an increase in securities income. Net income per diluted common share was $1.41 for the three months ended June 30, 2021 compared with $1.44 for the three months ended March 31, 2021, a decrease of 2.1%. Annualized returns on average assets, average common equity and average tangible common equity for the three months ended June 30, 2021 were 1.45%, 8.31% and 17.49%⁽¹⁾, respectively. Prosperity’s efficiency ratio (excluding net gains and losses on the sale or write down of assets and taxes) was 40.96%⁽¹⁾ for the three months ended June 30, 2021.

Net interest income before provision for credit losses for the three months ended June 30, 2021 was $245.4 million compared with $259.0 million for the same period in 2020, a decrease of $13.6 million or 5.2%. The decrease was primarily due to a decrease in the average loan balance and average rate on loans and a decrease in loan discount accretion of $12.1 million, partially offset by a decrease in the average rate on interest-bearing liabilities. On a linked quarter basis, net interest income before provision for credit losses was $245.4 million compared with $254.6 million for the three months ended March 31, 2021, a decrease of $9.2 million or 3.6%. The decrease was primarily due to a decrease in the average rate on loans and a decrease in loan discount accretion of $4.1 million, partially offset by a decrease in the average rate on interest-bearing liabilities and an increase in average investment securities balance.

The net interest margin on a tax equivalent basis was 3.11% for the three months ended June 30, 2021 compared with 3.69% for the same period in 2020. The change was primarily due to a decrease in the average loan balance and average rate on loans, an increase in lower yielding securities, a decrease in loan discount accretion of $12.1 million and higher cash balances due to excess liquidity, partially offset by a decrease in the average rate on interest-bearing liabilities. On a linked quarter basis, the net interest margin on a tax equivalent basis was 3.11% for the three months ended June 30, 2021 compared with 3.41% for the three months ended March 31, 2021. The change was primarily due to a lower average yield on loans, a $4.1 million decrease in loan discount accretion and higher net premium amortization on securities, partially offset by a decrease in the average rate on interest-bearing liabilities.

Noninterest income was $35.6 million for the three months ended June 30, 2021 compared with $25.7 million for the same period in 2020, an increase of $9.9 million or 38.5%. This increase was primarily due to an increase in credit card, debit card and ATM card income, an increase in mortgage income, lower loss on write-down of assets and an increase in other noninterest income. On a linked quarter basis, noninterest income increased $1.5 million or 4.6% to $35.6 million compared with $34.0 million for the three months ended March 31, 2021. This increase was primarily due to an increase in other noninterest income.

Noninterest expense was $115.2 million for the three months ended June 30, 2021 compared with $134.4 million for the same period in 2020, a decrease of $19.2 million or 14.3%, primarily due to decreases in merger related expenses, salaries and benefits and data processing as a result of efficiencies gained following the LegacyTexas Bank system conversion during the second quarter of 2020, partially offset by gains on sale of other real estate. On a linked quarter basis, noninterest expense decreased $3.9 million or 3.3% to $115.2 million compared with $119.1 million for the three months ended March 31, 2021. This decrease was primarily due to a decrease in salaries and benefits.

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Results of Operations for the Six Months Ended June 30, 2021

Net income was $263.9 million⁽⁵⁾ for the six months ended June 30, 2021 compared with $261.7 million⁽⁶⁾ for the same period in 2020, an increase of $2.2 million or 0.8%. Net income per diluted common share was $2.84 for the six months ended June 30, 2021 compared with $2.80 for the same period in 2020, an increase of 1.4%. Annualized returns on average assets, average common equity and average tangible common equity for the six months ended June 30, 2021 were 1.49%, 8.46% and 17.95%⁽¹⁾, respectively. Prosperity’s efficiency ratio (excluding net gains and losses on the sale or write down of assets and taxes) was 41.11%⁽¹⁾ for the six months ended June 30, 2021.

Net interest income before provision for credit losses for the six months ended June 30, 2021 was $500.0 million compared with $515.0 million for the prior year, a decrease of $15.0 million or 2.9%. The decrease was primarily due to a decrease in the average rate on interest-earning assets and a decrease in loan discount accretion of $24.2 million, partially offset by a decrease in the average rate on interest-bearing liabilities.

The net interest margin on a tax equivalent basis for the six months ended June 30, 2021 was 3.26% compared with 3.75% for the same period in 2020. The change was primarily due to an increase in lower yielding loans, a decrease in loan discount accretion of $24.2 million, higher net premium amortization on securities and higher cash balances due to excess liquidity, partially offset by a decrease in the average rate on interest-bearing liabilities.

Noninterest income was $69.6 million for the six months ended June 30, 2021 compared with $60.1 million for the same period in 2020, an increase of $9.5 million or 15.8%. This increase was primarily due to an increase in credit card, debit card and ATM card income, an increase in mortgage income, lower net loss on write-downs of assets and an increase in other noninterest income, partially offset by a decrease in nonsufficient funds (“NSF”) fees.

Noninterest expense was $234.3 million for the six months ended June 30, 2021 compared with $259.1 million for the same period in 2020, a decrease of $24.8 million or 9.6%. The change was primarily due to decreases in merger related expenses, data processing, net occupancy and equipment and other noninterest expense as a result of efficiencies gained following the LegacyTexas Bank system conversion during the second quarter of 2020, partially offset by a gain on sale of other real estate.

Balance Sheet Information

At June 30, 2021, Prosperity had $36.100 billion in total assets, an increase of $3.133 billion or 9.5% compared with $32.967 billion at June 30, 2020.

Loans at June 30, 2021 were $19.252 billion, a decrease of $1.773 billion or 8.4%, compared with $21.025 billion at June 30, 2020, primarily due to a decrease in commercial real estate, PPP and Warehouse Purchase Program loans. Linked quarter loans decreased $387.1 million or 2.0% from $19.639 billion at March 31, 2021, primarily due to a $359.1 million decrease in PPP loans. At June 30, 2021, the Company had $780.0 million of PPP loans compared to $1.392 billion of PPP loans at June 30, 2020 and $1.139 billion of PPP loans at March 31, 2021.  Linked quarter loans, excluding Warehouse Purchase Program and PPP loans, increased $148.8 million or 0.9% (3.7% annualized) from $16.227 billion at March 31, 2021.

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 June 30, 2021, oil and gas loans totaled $501.8 million (net of discount and excluding PPP loans totaling $92.3 million) or 2.6% of total loans, of which $283.1 million were production loans and $218.7 million were servicing loans, compared with total oil and gas loans of $639.4 million (net of discount and excluding PPP loans totaling $118.6 million) or 3.0% of total loans at June 30, 2020, of which $394.4 million were production loans and $245.0 million were servicing loans. In addition, as of June 30, 2021, Prosperity had total unfunded commitments to oil and gas companies of $298.4 million compared with total unfunded commitments to oil and gas companies of $276.9 million as of June 30, 2020. Unfunded commitments to producers include letters of credit issued in lieu of oil well plugging bonds.

Additionally, Prosperity extends credit to hotels and restaurants. At June 30, 2021, loans to hotels totaled $394.2 million (excluding PPP loans totaling $10.6 million) or 2.0% of total loans, an increase of $9.4 million or 2.4%, compared with $384.8 million (excluding PPP loans totaling $8.8 million) or 1.8% of total loans at June 30, 2020.  At June 30, 2021, loans to restaurants totaled $201.9 million (excluding PPP loans totaling $92.1 million) or 1.0% of total loans, a decrease of $10.4 million or 4.9%, compared with $212.3 million (excluding PPP loans totaling $110.7 million) or 1.0% of total loans at June 30, 2020.

Deposits at June 30, 2021 were $29.110 billion, an increase of $2.958 billion or 11.3%, compared with $26.153 billion at June 30, 2020. Linked quarter deposits increased $347.1 million or 1.2% (4.8% annualized) from $28.763 billion at March 31, 2021.

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Asset Quality

Nonperforming assets totaled $33.7 million or 0.11% of quarterly average interest-earning assets at June 30, 2021, compared with $77.9 million or 0.28% of quarterly average interest-earning assets at June 30, 2020, and $44.2 million or 0.15% of quarterly average interest-earning assets at March 31, 2021.

The allowance for credit losses on loans was $302.9 million or 1.57% of total loans at June 30, 2021 compared to $307.2 million or 1.56% of total loans at March 31, 2021 and $324.2 million or 1.54% of total loans at June 30, 2020. The allowance for credit losses on loans to total loans, excluding Warehouse Purchase Program and PPP loans, was 1.85%⁽¹⁾ at June 30, 2021 compared with 1.89%⁽¹⁾ at March 31, 2021 and 1.90%⁽¹⁾ at June 30, 2020.

There was no provision for credit losses for the three months ended June 30, 2021 compared with $10.0 million for the three months ended June 30, 2020 and no provision for credit losses for the three months ended March 31, 2021.  There was no provision for credit losses for the six months ended June 30, 2021 compared with $10.0 million for the six months ended June 30, 2020.

Net charge-offs were $4.3 million for the three months ended June 30, 2021 compared with net charge-offs of $13.0 million for the three months ended June 30, 2020 and net charge-offs of $8.9 million for the three months ended March 31, 2021. Net charge-offs for the second quarter of 2021 included $1.0 million related to resolved PCD loans. These PCD loans had specific reserves of $3.1 million, of which $1.0 million was allocated to the charge-offs and $2.1 million was moved to the general reserve. Further, an additional $1.4 million of specific reserves on resolved PCD loans without any related charge-offs was released to the general reserve.

Net charge-offs were $13.2 million for the six months ended June 30, 2021 compared with $13.8 million for the six months ended June 30, 2020. Net charge-offs for the six months ended June 30, 2021 included $8.2 million related to resolved PCD loans. These PCD loans had specific reserves of $9.8 million, of which $7.7 million was allocated to the charge-offs and $2.1 million was moved to the general reserve. Further, an additional $5.6 million of specific reserves on resolved PCD loans without any related charge-offs was released to the general reserve.

Dividend

Prosperity Bancshares declared a third quarter cash dividend of $0.49 per share to be paid on October 1, 2021 to all shareholders of record as of September 15, 2021.

COVID-19 Pandemic

Prosperity continues to monitor the latest developments regarding COVID-19. As of June 30, 2021, the states of Texas and Oklahoma have lifted their respective restrictions on all business and activities. The COVID-19 pandemic has resulted in significant economic uncertainties that have had, and could continue to have, an adverse impact on Prosperity’s operating income, financial condition and cash flows. The extent to which the COVID-19 pandemic will impact Prosperity’s operations and financial results during 2021 cannot be reasonably or reliably estimated at this time.

Since the implementation of the Paycheck Protection Program in 2020, Prosperity has obtained SBA approvals on approximately 18,700 loans totaling $2.036 billion and, as of June 30, 2021, had an outstanding balance of 7,770 loans totaling $780.0 million after remittance.

Also, in response to the COVID-19 pandemic, Prosperity has provided relief to its loan customers through loan extensions and deferrals. Prosperity’s troubled debt restructurings do not include loan modifications related to COVID-19. Beginning in mid-March of 2020, Prosperity began offering deferral and modification of principal and/or interest payments to selected borrowers on a case-by-case basis. As of June 30, 2021, Prosperity had approximately $210.4 million in outstanding loans subject to deferral and modification agreements.

Conference Call

Prosperity’s management team will host a conference call on Wednesday, July 28, 2021 at 11:30 a.m. Eastern Time (10:30 a.m. Central Time) to discuss Prosperity’s second quarter 2021 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 participant elite entry number is 4866823.

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, Webcast & Calls” from the menu on the Investor Relations link and following the instructions.

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Non-GAAP Financial Measures

Prosperity’s management uses certain non-GAAP financial measures to evaluate its performance. Specifically, Prosperity reviews diluted earnings per share excluding merger related expenses, net of tax, and net operating loss (“NOL”) tax benefit; return on average assets excluding merger related expenses, net of tax, and NOL tax benefit; return on average common equity excluding merger related expenses, net of tax, and NOL tax benefit; return on average tangible common equity; return on average tangible common equity excluding merger related expenses, net of tax, and NOL tax benefit; tangible book value per share; the tangible equity to tangible assets ratio; allowance for credit losses to total loans excluding Warehouse Purchase Program and PPP loans; the efficiency ratio, excluding net gains and losses on the sale or write down of assets and securities; and the efficiency ratio, excluding net gains and losses on the sale or write down of assets and securities and merger related expenses, for internal planning and forecasting purposes. Prosperity believes these non-GAAP financial measures provide information useful to investors in understanding Prosperity’s financial results and 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.

Prosperity Bancshares, Inc. ®

As of June 30, 2021, Prosperity Bancshares, Inc.^® is a $36.100 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 treasury management.

As of June 30, 2021, Prosperity operated 274 full-service banking locations: 65 in the Houston area, including The Woodlands; 30 in the South Texas area including Corpus Christi and Victoria; 64 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; and 8 in the Tulsa, Oklahoma area.

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, as well as expectations regarding the effects of the COVID-19 pandemic on Prosperity’s operating income, financial condition and cash flows.  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; 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;

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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, 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; the effect, impact, potential duration or other implications of the COVID-19 pandemic; and weather.  These and various other factors are discussed in Prosperity Bancshares’ Annual Report on Form 10-K for the year ended December 31, 2020 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.

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Prosperity Bancshares, Inc.^®

Financial Highlights (Unaudited)

(In thousands)

(A) Includes $1,394, $970, $974, $(442) and $(1,767) in unrealized gains (losses) on available for sale securities for the quarterly periods ended June 30, 2021, March 31, 2021, December 31, 2020, September 30, 2020 and June 30, 2020, respectively.

(B) Includes $1,101, $766, $770, $(349) and $(1,396) in after-tax unrealized gains (losses) on available for sale securities for the quarterly periods ended June 30, 2021, March 31, 2021, December 31, 2020, September 30, 2020 and June 30, 2020, respectively.

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Prosperity Bancshares, Inc.^®

Financial Highlights (Unaudited)

(In thousands)

(C) Interest income on securities was reduced by net premium amortization of $14,436, $12,844, $11,509, $10,089 and $9,224 for the three months ended June 30, 2021, March 31, 2021, December 31, 2020, September 30, 2020 and June 30, 2020, respectively, and $27,280 and $17,229 for the six months ended June 30, 2021 and June 30, 2020, respectively.

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Prosperity Bancshares, Inc. ^®

Financial Highlights (Unaudited)

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

(D) Includes purchase accounting adjustments for the periods presented as follows: