Accelerated stock awards for Middlefield Banc (MBCN) EVP Sarah Winters

Rhea-AI Filing Summary

Middlefield Banc Corp executive Sarah A. Winters reported equity compensation changes. On February 23, 2026, she acquired several blocks of common stock through accelerated vesting of RSUs and PSUs, including 7,954 shares at $35.18 per share, while 3,994 shares were disposed of to cover tax withholding.

Insider Trade Summary

5 transactions reported

Mixed 5 txns

Insider Winters Sarah A

Role EVP/CHRO

Type	Security	Shares	Price	Value
Grant/Award	Common Stock	1,708	$35.18	$60K
Grant/Award	Common Stock	1,886	$35.18	$66K
Grant/Award	Common Stock	1,999	$35.18	$70K
Grant/Award	Common Stock	7,954	$35.18	$280K
Tax Withholding	Common Stock	3,994	$35.18	$141K

Holdings After Transaction: Common Stock — 6,618 shares (Direct)

Footnotes (1)

1. The shares represent accelerated vesting of restricted stock units ("RSUs") resulting from action of the Middlefield Compensation Committee on February 23, 2026, approving the full vesting of all outstanding plan share awards, including the RSUs. For further information regarding the acceleration of the RSUs, please see the Form 8-K Current Report filed by Middlefield with the SEC on February 25, 2026. The restricted stock award was originally granted on September 4, 2024, and provides for vesting on the third anniversary of the award. The shares represent accelerated vesting of RSUs resulting from Compensation Committee approval on February 23, 2026. See the Form 8-K Current Report filed by Middlefield with the SEC on February 25, 2026. The restricted stock award was originally granted on January 17, 2025, and provides for vesting on the third anniversary of the award. The shares represent accelerated vesting of performance share units ("PSUs") resulting from action of the Middlefield Compensation Committee on February 23, 2026, approving the full vesting of all outstanding plan share awards, including the PSUs. See the Form 8-K Current Report filed by Middlefield with the SEC on February 25, 2026. The vesting conditions at grant were described in a Form 8-K filed on September 4, 2024. The shares represent accelerated vesting of PSUs resulting from action of the Middlefield Compensation Committee on February 23, 2026. See the Form 8-K Current Report filed by Middlefield with the SEC on February 25, 2026. The vesting conditions at grant were described in a Form 8-K filed on January 17, 2025.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Winters Sarah A

(Last) (First) (Middle)

15985 EAST HIGH STREET

(Street)

MIDDLEFIELD OH 44062

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MIDDLEFIELD BANC CORP [ MBCN ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP/CHRO

3. Date of Earliest Transaction (Month/Day/Year)
02/23/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	02/23/2026		A(1)		1,708	A	$35.18	6,618	D
Common Stock	02/23/2026		A(2)		1,886	A	$35.18	8,504	D
Common Stock	02/23/2026		A(3)		1,999	A	$35.18	10,503	D
Common Stock	02/23/2026		A(4)		7,954	A	$35.18	18,457	D
Common Stock	02/23/2026		F		3,994	D	$35.18	14,463	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The shares represent accelerated vesting of restricted stock units ("RSUs") resulting from action of the Middlefield Compensation Committee on February 23, 2026, approving the full vesting of all outstanding plan share awards, including the RSUs. For further information regarding the acceleration of the RSUs, please see the Form 8-K Current Report filed by Middlefield with the SEC on February 25, 2026. The restricted stock award was originally granted on September 4, 2024, and provides for vesting on the third anniversary of the award.

2. The shares represent accelerated vesting of RSUs resulting from Compensation Committee approval on February 23, 2026. See the Form 8-K Current Report filed by Middlefield with the SEC on February 25, 2026. The restricted stock award was originally granted on January 17, 2025, and provides for vesting on the third anniversary of the award.

3. The shares represent accelerated vesting of performance share units ("PSUs") resulting from action of the Middlefield Compensation Committee on February 23, 2026, approving the full vesting of all outstanding plan share awards, including the PSUs. See the Form 8-K Current Report filed by Middlefield with the SEC on February 25, 2026. The vesting conditions at grant were described in a Form 8-K filed on September 4, 2024.

4. The shares represent accelerated vesting of PSUs resulting from action of the Middlefield Compensation Committee on February 23, 2026. See the Form 8-K Current Report filed by Middlefield with the SEC on February 25, 2026. The vesting conditions at grant were described in a Form 8-K filed on January 17, 2025.

	/s/ Sarah A. Winters by Julie E. Shaw Power of Attorney	02/25/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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FAQ

What insider transactions did MBCN executive Sarah Winters report on February 23, 2026?

Sarah A. Winters reported multiple stock acquisitions from accelerated vesting of RSUs and PSUs and one tax-withholding disposition. All involved Middlefield Banc Corp common stock on February 23, 2026, reflecting equity compensation rather than open-market buying or selling activity.

How many Middlefield Banc (MBCN) shares were acquired through grants or awards?

The filing shows four separate acquisition transactions coded "A" in Middlefield Banc common stock. Each block reflects vested RSUs or PSUs approved by the Compensation Committee, rather than open-market purchases, and all are part of Winters’ direct ownership stake in the company.

What does the tax-withholding share disposition mean in the MBCN Form 4?

The Form 4 reports one transaction coded "F," a tax-withholding disposition of 3,994 Middlefield Banc shares. This indicates shares were withheld to satisfy tax obligations tied to vested awards, not a discretionary open-market sale by Sarah A. Winters.

Why were MBCN restricted stock and performance share units accelerated for Sarah Winters?

Footnotes state Middlefield’s Compensation Committee approved full vesting of outstanding plan share awards, including RSUs and PSUs, on February 23, 2026. This committee action triggered accelerated vesting of awards previously granted to Sarah A. Winters under prior grant dates.

What price per share is reported for Sarah Winters’ Middlefield Banc stock awards?

Each reported transaction in Middlefield Banc common stock uses a reference price of $35.18 per share. This figure appears across the acquisition and tax-withholding disposition entries and is used for valuing the equity compensation events in the Form 4.

Is the MBCN Form 4 for Sarah Winters a buy or a sell of shares?

The Form 4 reflects equity award vesting and one tax-withholding disposition, not open-market trades. Four transactions are coded as acquisitions from grants or awards, and one transaction is coded "F" for shares withheld to pay related tax liabilities.