Middlefield Banc (MBCN) 10-K 2022 FY Annual report

Exhibit 21

Middlefield Banc Corp. Subsidiaries

1 The Middlefield Banking Company (“MBC”), an Ohio-chartered commercial bank that began operations in 1901, engages in general commercial banking in northeastern and central Ohio. MBC’s consolidated financial statements also include the accounts of MBC’s subsidiaries, Middlefield Investments, Inc. (“MI”), established in March of 2019, MB Insurance Services, LLC. (MIS), established in March of 2022, and LBSI Insurance, LLC. The principal executive office is located at 15985 East High Street, Middlefield, Ohio 44062-0035.

2 On October 23, 2009 Middlefield received approval from the Federal Reserve Bank of Cleveland to establish an asset resolution subsidiary. Organized as an Ohio corporation under the name EMORECO, Inc. and wholly owned by Middlefield Banc Corp, the purpose of the asset resolution subsidiary is to maintain, manage, and ultimately dispose of nonperforming loans and real estate acquired by the subsidiary bank as the result of borrower default on real estate-secured loans.