X0508 4 2025-12-17 0000836147 MIDDLEFIELD BANC CORP MBCN 0001954793 Zimmerly Ronald Len Jr. 15985 EAST HIGH STREET MIDDLEFIELD OH 44062 1 1 Chief Executive Officer 0 Common Stock 2025-12-17 4 A 0 4653 37 A 43169.283 D Common Stock 2025-12-17 4 A 0 10161 37 A 53330.283 D Common Stock 2025-12-17 4 F 0 4126 37 D 49204.283 D Common Stock 8786 I Held in IRA Conditional Stock Award 2027-08-30 Common Stock 4520 4520 D Conditional Stock Award 2028-01-14 Common Stock 6864 6864 D Amendment of conditional stock award agreement resulting in acceleration of restricted stock grants. The details of the accelerated restricted stock grants may be found in a Form 8-K filed December 12, 2025. Amendment of performance share unit award agreement resulting in acceleration of performance share unit grants. The details of the accelerated performance share unit grants may be found in a Form 8-K filed December 12, 2025. Includes shares acquired under MBCN Dividend Reinvestment Plan The award represents a grant of restricted stock which vests ratably over a three-year period provided that Mr. Zimmerly remains continuously employed by Middlefield as of each vesting date. Until the award vests, the award confers no right to vote, no right to dividends, and no other shareholder rights to the recipient. The details of the vesting conditions may be found in a Form 8K filing dated September 4, 2024. The award represents a grant of restricted stock which vests ratably over a three-year period provided that Mr. Zimmerly remains continuously employed by Middlefield as of each vesting date. Until the award vests, the award confers no right to vote, no right to dividends, and no other shareholder rights to the recipient. The details of the vesting conditions may be found in a Form 8K filing dated January 17, 2025. Each restricted stock unit represents the right to receive, at settlement, one share of common stock. /s/ Ronald L. Zimmerly, Jr. by Julie E. Shaw Power of Attorney 2025-12-18