X0508 4 2025-06-27 0000836147 MIDDLEFIELD BANC CORP MBCN 0001286842 MCCASKEY JAMES J 15985 EAST HIGH STREET MIDDLEFIELD OH 44062 1 0 Common Stock 5523.79 D Common Stock 4706.314 D Common Stock 1372 I held by spouse in retirement account Conditional Stock Award 2025-06-27 4 A 0 405 A 2026-06-27 Common Stock 405 405 D Includes shares acquired under MBCN Dividend Reinvestment Plan Includes shares held jointly with spouse. Granted under the Director Compensation program for members of the Board of Directors of The Middlefield Banking Company. The award represents a grant of restricted stock units which vest upon the earlier of the one-year anniversary of the grant date or the date of the annual meeting of shareholders which occurs in the year following the year of the grant date. If the recipient ceases to be a member of the board of the directors of The Middlefield Banking Company for any reason other than death or disability prior to the vesting date, any unvested RSUs shall be forfeited. Until the award vests, the award confers no right to vote, no right to dividends, and no other shareholder rights to the recipient. Each restricted stock unit represents the right to receive, at settlement, one share of common stock. /s/ James J. McCaskey by Julie E. Shaw Power of Attorney 2025-07-01