Exhibit 99

15985 East High Street

P. O. Box 35

Middlefield, Ohio 44062

Phone: 440/632-1666 FAX: 440/632-1700

www.middlefieldbank.bank

Middlefield Banc Corp. Reports 2023 First Quarter Financial Results

MIDDLEFIELD, OHIO, April 24, 2023 ¨¨¨¨ Middlefield Banc Corp. (NASDAQ: MBCN) today reported financial results for the 2023 first quarter ended March 31, 2023.

2023 First Quarter Financial Highlights Include (on a year-over-year basis unless noted):

“Middlefield’s first-quarter results and record quarterly net income demonstrate our strong balance sheet, robust asset quality, and diverse core deposit base, as well as the benefits and added scale of the Liberty Bancshares, Inc. merger. Despite macro-level concerns related to the health of the banking system, higher interest rates, and a slowing economy, we remained focused on successfully integrating the Liberty Bancshares merger and serving our customers across our Central, Western, and Northeast Ohio communities. I am encouraged by the deposit, loan, and earnings growth we achieved over the past three months, all of which is a testament to the experience of our management team and the dedication of our team members.” stated James R. Heslop, II, Chief Executive Officer.

“We expect higher rates and competition for deposits will continue to increase our cost of funds in the coming quarters, but we believe our compelling net interest margin and larger loan portfolio will support strong levels of interest income throughout the year. I am pleased to report that we achieved the highest quarterly net interest margin in over 20 years and the fourth consecutive quarter above 4%. As the year progresses, we remain focused on growth opportunities across our expanded Ohio markets, adding talented bankers to our platform, and maintaining strong asset quality,” concluded Mr. Heslop.

Income Statement

Net interest income for the 2023 first quarter was $16.5 million, compared to $11.5 million for the 2022 first quarter. The net interest margin for the 2023 first quarter was 4.26%, compared to 3.80% for the same period of 2022. For the 2023 first quarter, noninterest income increased 19.6% to $1.7 million from $1.4 million for the same period of 2022.

Noninterest expense was $11.8 million for the 2023 first quarter compared to $8.3 million for the 2022 first quarter. During the first quarter of 2023, the Company incurred $245,000 of additional operating expenses associated with the Liberty Bancshares, Inc.

Pre-tax income during last year’s first quarter benefited from $640,000 of accelerated net fees associated with the Paycheck Protection Program (“PPP”).

Net income for the 2023 first quarter was a quarterly record of $4.9 million, or $0.60 per diluted share, compared to $3.8 million, or $0.65 per diluted share, for the same period last year.

Pre-tax, pre-provision net income was a quarterly record of $6.4 million, an increase of 38.8% from $4.6 million last year.

Balance Sheet

Total assets at March 31, 2023, increased 30.6% to $1.73 billion, compared to $1.32 billion at March 31, 2022. Net loans at March 31, 2023, increased 41.5% to $1.36 billion, compared to $963.2 million at March 31, 2022. Total assets increased 2.4% from December 31, 2022.

Total deposits at March 31, 2023, were $1.43 billion, compared to $1.17 billion at March 31, 2022. The 22.1% deposit increase was primarily due to the Liberty Bancshares, Inc. merger. Total deposits at March 31, 2023, increased 1.7% from December 31, 2022.

Donald L. Stacy, Chief Financial Officer, stated, “We ended the quarter with a net loan-to-deposit ratio of 95.6%, $66.7 million in cash and cash equivalents, and $169.6 million in investment securities. In addition, our unrealized losses on all securities at the end of the month were a modest 9.0% of total capital. Considering our strong capital levels, robust liquidity, and diverse loan and deposit portfolios, along with our maximum borrowing capacity of $560 million at the Federal Home Loan Bank, we decided not to use the Federal Reserve’s Bank Term Funding Program. During the first quarter, we repurchased 164,221 shares at an average of $27.44 per share and have 293,910 shares remaining under our February 2023 repurchase program.”

Middlefield’s CRE portfolio included the following categories at March 31, 2023:

Stockholders’ Equity and Dividends

At March 31, 2023, stockholders’ equity was $195.2 million compared to $137.6 million at March 31, 2022. The 41.8% year-over-year increase in stockholders’ equity is primarily due to the Liberty Bancshares, Inc. merger, partially offset by an increase in the unrealized loss on the available-for-sale investment portfolio and the Company’s stock repurchase program. On a per-share basis, shareholders’ equity at March 31, 2023, was $24.13 compared to $23.43, an increase of 3.0% over the same period last year.

At March 31, 2023, tangible stockholders’ equity(1) was $156.0 million for the 2023 first quarter, compared to $121.2 million at March 31, 2022. On a per-share basis, tangible stockholders’ equity(1) was $19.29 at March 31, 2023, compared to $20.64 at March 31, 2022.

For the 2023 first quarter, cash dividends declared per share increased 17.6% to $0.20 per share totaling $1.6 million, compared to $0.17 per share or $1.0 million, for the first quarter last year.

At March 31, 2023, the Company had an equity-to-assets leverage ratio of 11.30%, compared to 10.40% at March 31, 2022.

Asset Quality

The Company recorded a provision for loan losses of $507,000 for the 2023 first quarter versus no provision for loan losses for the same period last year.

On January 1, 2023, Middlefield adopted ASU 2016-13—Measurement of Credit Losses on Financial Instruments and implemented the current expected credit losses (“CECL”) accounting standards. Upon adoption, the reserve for credit losses on loans and leases increased by $5.3 million, the reserve for credit losses for unfunded commitments increased by $622,000. This resulted in an after-tax retained earnings adjustment of $4.4 million. During the quarter ended March 31, 2023, the Corporation recorded CECL related charges of $507,000, including a provision for credit losses on loans and leases of $334,000 and a reserve for unfunded commitments of $173,000.

Net recoveries were $8,000, or 0.00% of average loans, annualized, during the 2023 first quarter, compared to net recoveries of $150,000, or 0.06% of average loans, annualized, at March 31, 2022.

Nonperforming assets at March 31, 2023, were $12.7 million, compared to $11.7 million at March 31, 2022. Nonperforming loans at March 31, 2023, increased to $6.9 million, from $4.7 million at March 31, 2022 primarily due to the additional loans from the Liberty Bancshares, Inc. merger. The allowance for credit losses at March 31, 2023, stood at $20.2 million, or 1.46% of total loans, compared to $14.5 million, or 1.48% of total loans at March 31, 2022.

About Middlefield Banc Corp.

Middlefield Banc Corp., headquartered in Middlefield, Ohio, is the Bank holding Company of The Middlefield Banking Company, with total assets of $1.73 billion at March 31, 2023. The Bank operates 21 full-service banking centers and an LPL Financial® brokerage office serving Ada, Beachwood, Bellefontaine, Chardon, Cortland, Dublin, Garrettsville, Kenton, Mantua, Marysville, Middlefield, Newbury, Orwell, Plain City, Powell, Solon, Sunbury, Twinsburg, and Westerville. The Bank also operates a Loan Production Office in Mentor, Ohio.

Additional information is available at www.middlefieldbank.bank

(1) NON-GAAP FINANCIAL MEASURES

This press release includes disclosure of Middlefield Banc Corp.’s tangible book value per share, return on average tangible equity, and pre-tax, pre-provision for loan losses income, which are financial measures not prepared in accordance with generally accepted accounting principles in the United States (GAAP). A non-GAAP financial measure is a numerical measure of historical or future financial performance, financial position or cash flows that excludes or includes amounts that are required to be disclosed by GAAP. Middlefield Banc Corp. believes that these non-GAAP financial measures provide both management and investors a more complete understanding of the underlying operational results and trends and Middlefield Banc Corp.’s marketplace performance. The presentation of this additional information is not meant to be considered in isolation or as a substitute for the numbers prepared in accordance with GAAP. The reconciliations of non-GAAP financial measures are included in the tables following Consolidated Financial Highlights below.

FORWARD-LOOKING STATEMENTS

This press release of Middlefield Banc Corp. and the reports Middlefield Banc Corp. files with the Securities and Exchange Commission often contain “forward-looking statements” relating to present or future trends or factors affecting the banking industry and, specifically, the financial operations, markets and products of Middlefield Banc Corp. These forward-looking statements involve certain risks and uncertainties. There are a number of important factors that could cause Middlefield Banc Corp.’s future results to differ materially from historical performance or projected performance. These factors include, but are not limited to: (1) a significant increase in competitive pressures among financial institutions; (2) changes in the interest rate environment that may reduce interest margins; (3) changes in prepayment speeds, charge-offs and loan loss provisions; (4) less favorable than expected general economic conditions; (5) legislative or regulatory changes that may adversely affect businesses in which Middlefield Banc Corp. is engaged; (6) technological issues which may adversely affect Middlefield Banc Corp.’s financial operations or customers; (7) changes in the securities markets; or (8) risk factors mentioned in the reports and registration statements Middlefield Banc Corp. files with the Securities and Exchange Commission. Middlefield Banc Corp. undertakes no obligation to release revisions to these forward-looking statements or to reflect events or circumstances after the date of this press release.

MIDDLEFIELD BANC CORP.

Consolidated Selected Financial Highlights

(Dollar amounts in thousands, unaudited)

MIDDLEFIELD BANC CORP.

Consolidated Selected Financial Highlights

(Dollar amounts in thousands, unaudited)

MIDDLEFIELD BANC CORP.

Consolidated Selected Financial Highlights

(Dollar amounts in thousands, except per share and share amounts, unaudited)

MIDDLEFIELD BANC CORP.

Consolidated Selected Financial Highlights

(Unaudited)

MIDDLEFIELD BANC CORP.

Average Balance Sheets

(Dollar amounts in thousands, unaudited)