# EDGAR Filing Document

**Accession Number:** 0001666749
**File Stem:** 0001104659-26-010329
**Filing Date:** 2026-2
**Character Count:** 11042
**Document Hash:** 36abd2ff9379426e39e518e553f8e5a6
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-26-010329.hdr.sgml**: 20260204

**ACCESSION NUMBER**: 0001104659-26-010329

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13D/A

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260204

**DATE AS OF CHANGE**: 20260204

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MIDDLEFIELD BANC CORP
- **CENTRAL INDEX KEY:** 0000836147
- **STANDARD INDUSTRIAL CLASSIFICATION:** STATE COMMERCIAL BANKS [6022]
- **ORGANIZATION NAME:** 02 Finance
- **EIN:** 341585111
- **STATE OF INCORPORATION:** OH
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-86838
- **FILM NUMBER:** 26598588

**BUSINESS ADDRESS:**
- **STREET 1:** 15985 EAST HIGH STREET
- **STREET 2:** P O BOX 35
- **CITY:** MIDDLEFIELD
- **STATE:** OH
- **ZIP:** 44062-9263
- **BUSINESS PHONE:** 4406321666

**MAIL ADDRESS:**
- **STREET 1:** 15985 EAST HIGH STREET
- **STREET 2:** P O BOX 35
- **CITY:** MIDDLEFIELD
- **STATE:** OH
- **ZIP:** 44062-9263
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Castle Creek Capital Partners VI, LP
- **CENTRAL INDEX KEY:** 0001666749

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A

**BUSINESS ADDRESS:**
- **STREET 1:** 11682 EL CAMINO REAL SUITE 320
- **CITY:** SAN DIEGO
- **STATE:** CA
- **ZIP:** 92130
- **BUSINESS PHONE:** (858)756-8300

**MAIL ADDRESS:**
- **STREET 1:** 11682 EL CAMINO REAL SUITE 320
- **CITY:** SAN DIEGO
- **STATE:** CA
- **ZIP:** 92130

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

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 1)**

**MIDDLEFIELD BANC CORP.**

*(Name of Issuer)*

**Common Stock, no par value**

*(Title of Class of Securities)*

**596304204**

*(CUSIP Number)*

**Deborah Sykes**<br>11682 El Camino Real, Suite 320<br>San Diego CA 92130<br>858-756-8300

*(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)*

**01/30/2026**

*(Date of Event Which Requires Filing of this Statement)*

| **CUSIP No.** | **596304204** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Castle Creek Capital Partners VI, LP** | Name of reporting person<br>**Castle Creek Capital Partners VI, LP** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**312847.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**312847.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**312847.00** | Aggregate amount beneficially owned by each reporting person<br>**312847.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**3.9%** | Percent of class represented by amount in Row (11)<br>**3.9%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

**Comment for Reporting Person:** (1) The information set forth in Item 5 of this statement on Schedule 13D is incorporated herein by reference.

| **CUSIP No.** | **596304204** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Castle Creek Capital VI LLC** | Name of reporting person<br>**Castle Creek Capital VI LLC** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**312847.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**312847.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**312847.00** | Aggregate amount beneficially owned by each reporting person<br>**312847.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**3.9%** | Percent of class represented by amount in Row (11)<br>**3.9%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**HC** | Type of Reporting Person (See Instructions)<br>**HC** | |

---

**Comment for Reporting Person:** (1) The information set forth in Item 5 of this statement on Schedule 13D is incorporated herein by reference.

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Common Stock, no par value

**(b) Name of Issuer:**
MIDDLEFIELD BANC CORP.

**(c) Address of Issuer's Principal Executive Offices:**
15985 East High Street, Middlefield, OH, 44062

This Amendment No. 1 to Schedule 13D (this "Amendment No. 1") amends and supplements the Schedule 13D filed on December 9, 2022 (the "Schedule 13D") with the U.S. Securities and Exchange Commission (the "SEC"), relating to the shares of common stock, no par value per share ("Voting Common Stock"), of Middlefield Banc Corp. (the "Issuer" or the "Company").  Unless specifically amended hereby, the disclosures set forth in the Schedule 13D remain unchanged.  Capitalized terms used in this Amendment No. 1 that are not otherwise defined herein have the meanings attributed to them in the Schedule 13D.

**Item 5. Interest in Securities of the Issuer**

**(a)**
Item 5(a) and (b) of the Schedule 13D is hereby amended and supplemented as follows:

Fund VI owns 312,847 shares of the Voting Common Stock, which represents approximately 3.9%* of the Voting Common Stock.

*This calculation is based on 8,090,067 shares of Voting Common Stock of the Company outstanding as of December 12, 2025, as reported in the Company's proxy statement on Schedule 14A filed with the SEC on December 19, 2025.

**(b)**
Fund VI has shared power to vote or direct the vote and shared power to dispose or direct the disposition of the 312,847 shares of Voting Common Stock described above with CCC VI.  CCC VI disclaims beneficial ownership of the Voting Common Stock beneficially owned by Fund VI, except to the extent of its pecuniary interest therein.

**(c)**
Item 5(c) of the Schedule 13D is hereby amended and supplemented as follows:

Except as previously disclosed in the Schedule 13D, Fund VI has engaged in the following open market, broker-assisted transactions with respect to the Voting Common Stock during the last 60 days through the date of the event which requires filing of this Schedule 13D:

(i) 16,813 shares of Voting Common Stock sold on December 12, 2025 at a weighted average price of $37.17 per share (in multiple open market, broker-assisted transactions ranging from $36.90 to $37.25 per share, inclusive); (ii) 13,579 shares of Voting Common Stock sold on December 15, 2025 at a weighted average price of $37.00 per share (in multiple open market, broker-assisted transactions ranging from $37.00 to $37.18 per share, inclusive); (iii) 5,627 shares of Voting Common Stock sold on December 16, 2025 at a weighted average price of $37.01 per share (in multiple open market, broker-assisted transactions ranging from $37.00 to $37.095 per share, inclusive); (iv) 5,302 shares of Voting Common Stock sold on December 17, 2025 at a weighted average price of $37.12 per share (in multiple open market, broker-assisted transactions ranging from $37.00 to $37.20 per share, inclusive); (v) 12,909 shares of Voting Common Stock sold on December 18, 2025 at a weighted average price of $37.04 per share (in multiple open market, broker-assisted transactions ranging from $36.90 to $37.27 per share, inclusive); (vi) 200 shares of Voting Common Stock sold on December 19, 2025 at a price of $36.90 per share; (vii) 18,008 shares of Voting Common Stock sold on January 22, 2026 at a weighted average price of $36.12 per share (in multiple open market, broker-assisted transactions ranging from $36.00 to $36.505 per share, inclusive); (viii) 72,772 shares of Voting Common Stock sold on January 30, 2026 at a weighted average price of $33.57 per share (in multiple open market, broker-assisted transactions ranging from $33.50 to $33.79 per share, inclusive); and (ix) 102,443 shares of Voting Common Stock sold on February 2, 2026 at a weighted average price of $33.61 per share (in multiple open market, broker-assisted transactions ranging from $33.30 to $33.98 per share, inclusive).

### SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** Castle Creek Capital Partners VI, LP

**Signature:** /s/ Tony Scavuzzo

**Name/Title:** Tony Scavuzzo, Managing Principal

**Date:** 02/03/2026

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** Castle Creek Capital VI LLC

**Signature:** /s/ Tony Scavuzzo

**Name/Title:** Tony Scavuzzo, Managing Principal

**Date:** 02/03/2026