Exhibit 99

15985 East High Street

P. O. Box 35

Middlefield, Ohio 44062

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

www.middlefieldbank.bank

PRESS RELEASE

Middlefield Banc Corp. Reports 2016 First Quarter Financial Results

MIDDLEFIELD, OHIO, April 21, 2016 ¿¿¿¿ Middlefield Banc Corp. (NASDAQ: MBCN) today reported financial results for the 2016 first quarter ended March 31, 2016.

2016 First Quarter Financial Highlights Include (on a year-over-year basis unless noted):

“We were pleased with our first quarter results, as net loans grew 11.6% and tangible book value per share increased 6.0% over the same period last year,” stated Thomas G. Caldwell, President and Chief Executive Officer. “As we expected, the first quarter reflects the additional expenses from our new Mentor LPO and the addition of several new loan officers, which contributed to an 11.0% increase in noninterest expenses from the 2015 first quarter. We anticipate loan growth to show significant sequential improvements in the 2016 second quarter driven by increased productivity from our new lenders. In addition, we are making progress growing our secondary mortgage program as we enter the strong residential real estate selling season. For the 2016 first quarter, fees generated by selling residential mortgages increased nearly 30% from the same period a year ago. We continue to believe 2016 will benefit from the full-year contribution of our new lenders, business managers and Mentor LPO, and we are optimistic this will drive higher assets and loans, and improved profitability.”

Net income for the 2016 first quarter was $1.5 million, or $0.79 per diluted share, compared to net income for the 2015 first quarter of $1.6 million, or $0.79 per diluted share. Annualized returns on average equity (“ROE”) and average assets (“ROA”) for the 2016 first quarter were 9.34% and 0.81%, respectively, compared with 10.23% and 0.96% for the 2015 first quarter.

Mr. Caldwell continued: “We continue to execute on the strategic plan we developed last year and the strong team of dedicated associates we assembled is starting to contribute to our next phase of growth. We operate in competitive markets and having a strong team in place is critical for our success. As other banks within our markets focus on consolidation, our emphasis continues to be on growing our market share by providing customers with our core community banking values. I am excited about our opportunities in 2016.”

Income Statement

Net interest income for the 2016 first quarter was $6.3 million, compared to nearly $6.2 million for the 2015 first quarter. The 2.8% increase in net interest income for the 2016 first quarter was a result of a 5.6% increase in interest and fees on loans. The net interest margin for the 2016 first quarter was 3.87%, compared to 4.02% for the same period of 2015.

Noninterest income for the 2016 first quarter was up 14.2% to $0.9 million, primarily a result of gains on the sales of investments and loans, as well as on earnings on bank-owned life insurance. Noninterest expense for the 2016 first quarter was $5.3 million, an increase of approximately $0.5 million from the 2015 first quarter. The higher noninterest expenses were primarily because of higher salaries, employee benefits, and operating expenses to support the company’s growth objectives.

“Our asset quality remains strong, as charge offs declined 73.6% from the first quarter last year,” said Donald L. Stacy, Chief Financial Officer. “Nonperforming loans are up year-over-year mainly due to the overall increase in our loan portfolio. While we expect strong loan growth in the 2016 second quarter, we remain focused on managing risk and maintaining high quality lending practices. We had $30.2 million in cash and cash equivalents on our balance sheet at March 31, 2016 and net loans to total deposits of 83.0%. Looking at expenses, the main driver of the increase in 2016 first quarter noninterest expenses was higher salary and benefit costs as a result of the investments we made last year in personnel. We expect to leverage these costs as our lenders close loans and increase the size of our portfolio. In addition, we expect to see further improvements in noninterest income, which will help offset higher operating expenses.”

Balance Sheet

Total assets at March 31, 2016 increased 4.7% to $732.9 million, from $700.0 million at March 31, 2015. Net loans at March 31, 2016 were $524.0 million, compared to $469.4 million at March 31, 2015. The 11.6% year-over-year improvement in net loans was a result of loan growth in both residential and commercial mortgages, which increased 11.7% and 18.7%, respectively, as well as a 9.5% increase in consumer installment loans. This improvement more than offset a 7.1% year-over-year decrease in commercial and industrial and real estate construction loans.

Total deposits at March 31, 2016 increased 2.3% to $631.4 million from $617.1 million at March 31, 2015. The company continued to proactively manage its cost of funds and control deposit growth. The investment portfolio, which is entirely classified as available for sale, was $142.6 million at March 31, 2016, compared with $151.2 million at March 31, 2015.

Stockholders’ Equity and Dividends

Tangible stockholders’ equity decreased 3.0% to $59.1 million for the 2016 first quarter, compared to $61.0 million at March 31, 2015. On a per share basis, tangible stockholders’ equity increased 6.0% to $31.42 at March 31, 2016 from $29.65 at March 31, 2015. In October 2015, the Company repurchased 196,635 shares of its common stock. At March 31, 2016, the company had a Tier 1 leverage ratio of 9.19%, down from 9.70% at March 31, 2015.

During the 2016 first quarter, the company paid cash dividends of $0.27 per share, which represents a dividend payout ratio of 34.1%.

Asset Quality

The provision for loan losses for both the 2016 and 2015 first quarter were $0.1 million. Nonperforming assets at March 31, 2016 were $12.0 million, compared to $10.5 million at March 31, 2015. Net charge-offs for the 2016 first quarter were $0.1 million, or 0.10% of average loans, annualized compared to $0.5 million, or 0.4.3% of average loans, annualized. The allowance for loan losses at March 31, 2016 stood at $6.4 million, or 1.20% of total loans, compared to $6.4 million or 1.35% of total loans at March 31, 2015.

The following table provides a summary of asset quality and reserve coverage ratios.

Asset Quality History

(dollars in thousands)

Middlefield Banc Corp., headquartered in Middlefield, Ohio, is a bank holding company with total assets of $732.9 million at March 31, 2016. The bank operates 10 full service banking centers and an LPL Financial^® brokerage office serving Chardon, Cortland, Dublin, Garrettsville, Mantua, Middlefield, Newbury, Orwell, and Westerville. The Bank also operates a Loan Production Office in Mentor, Ohio. Additional information is available at www.middlefieldbank.bank.

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

March 31, 2016 and 2015

(Dollar amounts in thousands)

(unaudited)

MIDDLEFIELD BANC CORP.

Consolidated Selected Financial Highlights

March 31, 2016 and 2015 and December 31, 2015