Sarah A. Winters - 17 Dec 2025 Form 4 Insider Report for MIDDLEFIELD BANC CORP (MBCN)

Role: EVP/CHRO
Signature: /s/ Sarah A. Winters by Julie E. Shaw Power of Attorney
Issuer symbol: MBCN
Transactions as of: 17 Dec 2025
Net transactions value: +$136,419
Form type: 4
Filing time: 18 Dec 2025, 17:38:26 UTC
Previous filing: 07 Aug 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Winters Sarah A	EVP/CHRO	15985 EAST HIGH STREET, MIDDLEFIELD	/s/ Sarah A. Winters by Julie E. Shaw Power of Attorney	18 Dec 2025	0002008413

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	MBCN	Common Stock	Award	$192,548	+5,204	+860%	$37.00	5,809	17 Dec 2025	Direct	F1
transaction	MBCN	Common Stock	Tax liability	$56,129	-1,517	-26%	$37.00	4,292	17 Dec 2025	Direct

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
holding	MBCN	Conditional Stock Award						1,708	17 Dec 2025	Common Stock	1,708		Direct	F3, F4
holding	MBCN	Conditional Stock Award						2,828	17 Dec 2025	Common Stock	2,828		Direct	F2, F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Amendment of performance share unit award agreement resulting in acceleration of performance share unit grants. The performance share unit award was originally granted on August 6, 2024, and provides for vesting in any earned performance share units upon the payment date, defined as within sixty days after December 31, 2026.
F2	The award represents a grant of restricted stock which vests ratably over a three-year period provided that Mrs. Winters 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 8-K filing dated January 17, 2025.
F3	Each restricted stock unit represents the right to receive, at settlement, one share of common stock.
F4	The award represents a grant of restricted stock which vests ratably over a three-year period provided that Mrs. Winters 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 8-K filing dated September 4, 2024.