MNSB / MainStreet Bancshares, Inc. - SEC Dosyaları, Yıllık Rapor, Vekil Beyanı

As filed with the Securities and Exchange Commission on June 3, 2026

As filed with the Securities and Exchange Commission on June 3, 2026 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 26, 2026 MainStreet Bancshare

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 26, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 22, 2026 MainStreet Bancshare

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 22, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissio

MAINSTREET BANCSHARES, INC. _____________________________, as Trustee Dated as of , 202_

Exhibit 4.5 MAINSTREET BANCSHARES, INC. AND , as Trustee INDENTURE Dated as of , 202 SUBORDINATED DEBT SECURITIES TABLE OF CONTENTS Page ARTICLE ONE DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION 1 SECTION 101. Definitions 1 SECTION 102. Compliance Certificates and Opinions 8 SECTION 103. Form of Documents Delivered to Trustee 8 SECTION 104. Acts of Holders 8 SECTION 105. Notices, etc. 10

As filed with the Securities and Exchange Commission on May 15, 2026

As filed with the Securities and Exchange Commission on May 15, 2026 Registration No.

MAINSTREET BANCSHARES, INC. as Trustee Dated as of , 202_ SENIOR DEBT SECURITIES TABLE OF CONTENTS

Exhibit 4.4 MAINSTREET BANCSHARES, INC. AND as Trustee INDENTURE Dated as of , 202 SENIOR DEBT SECURITIES TABLE OF CONTENTS Page ARTICLE ONE DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION 1 SECTION 101. Definitions 1 SECTION 102. Compliance Certificates and Opinions 7 SECTION 103. Form of Documents Delivered to Trustee 7 SECTION 104. Acts of Holders 8 SECTION 105. Notices, etc. 8 SECTION

As filed with the Securities and Exchange Commission on May 15, 2026

As filed with the Securities and Exchange Commission on May 15, 2026 Registration No.

Security Type

Calculation of Filing Fee Tables S-3 MainStreet Bancshares, Inc. Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-38817 MainStree

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended March 31, 2026, as filed with the Securities and Exchange Commission (the “Report”), we hereby certify, pursuant to 18 U.S.C. Section 1350, as ado

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 24, 2026 MainStreet Bancsha

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 24, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commiss

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 21, 2026 MainStreet Bancsha

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 21, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commiss

MainStreet Bancshares, Inc. Announces First Quarter 2026 Results Net Interest Margin Expands on Disciplined Funding Strategy

Exhibit 99.1 PRESS RELEASE Contact: Billy Freesmeier April 20, 2026 8:00 AM ET Chief of Staff (703) 481-4579 MainStreet Bancshares, Inc. Announces First Quarter 2026 Results Net Interest Margin Expands on Disciplined Funding Strategy Fairfax, VA., April 20, 2026 – MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the financial holding company for MainStreet Bank, reported a net income of $4.1 mi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: April 20, 2026 MainStreet B

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: April 20, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (C

EXHIBIT 99.2

Exhibit 99.2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D. C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D. C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Defin

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UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 13, 2026 MainStreet Bancsha

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 13, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commiss

MainStreet Bank Elevates David Murrell to Executive VP & Chief Banking Officer Leveraging nearly two decades of institutional knowledge to drive deposit growth

Exhibit 99.1 PRESS RELEASE Contact: Billy Freesmeier APRIL 13, 2026 8:00 ET Chief of Staff (703) 481-4579 MainStreet Bank Elevates David Murrell to Executive VP & Chief Banking Officer Leveraging nearly two decades of institutional knowledge to drive deposit growth FAIRFAX, VA, April 13, 2026 — MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP) is pleased to announce the promotion of David Murrell

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 6, 2026 MainStreet Bancshar

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 6, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

MainStreet Bank Appoints Morgan Higgins to Board of Directors New Director Brings Significant Government Contract Financing Expertise

Exhibit 99.1 PRESS RELEASE Contact: Billy Freesmeier FOR IMMEDIATE RELEASE Chief of Staff (703) 481-4579 MainStreet Bank Appoints Morgan Higgins to Board of Directors New Director Brings Significant Government Contract Financing Expertise Fairfax, VA, March 25, 2026 — MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the financial holding company for MainStreet Bank, announces the appointment of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 25, 2026 MainStreet Bancsha

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 25, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commiss

Policy Statement on Insider Trading and Confidentiality Adopted July 17, 2024

Exhibit 19.0 Policy Statement on Insider Trading and Confidentiality Adopted July 17, 2024 To: All directors, officers, and other employees of, and consultants and other service providers to, the Company. This Policy Statement confirms procedures that such persons at every level must follow, arising from our responsibilities as a public company. MainStreet Bancshares, Inc. and MainStreet Bank (col

Subsidiaries of the Registrant

EXHIBIT 21.1 Subsidiaries of the Registrant Parent MainStreet Bancshares, Inc. State or Other Jurisdiction of Incorporation Subsidiaries Percentage Ownership MainStreet Bank Virginia 100% MainStreet Community Capital, LLC Virginia 100% ORE Holding LLC District of Columbia 100%

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the annual report on Form 10-K of MainStreet Bancshares, Inc. (the “Company”) for the fiscal year ended December 31, 2025 as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as a

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-38817 MainStreet Banc

Policy Statement on Insider Trading and Confidentiality Adopted July 17, 2024

Exhibit 19.0 Policy Statement on Insider Trading and Confidentiality Adopted July 17, 2024 To: All directors, officers, and other employees of, and consultants and other service providers to, the Company. This Policy Statement confirms procedures that such persons at every level must follow, arising from our responsibilities as a public company. MainStreet Bancshares, Inc. and MainStreet Bank (col

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the annual report on Form 10-K/A of MainStreet Bancshares, Inc. (the “Company”) for the fiscal year ended December 31, 2024 as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as

Subsidiaries of the Registrant

EXHIBIT 21.1 Subsidiaries of the Registrant Parent MainStreet Bancshares, Inc. State or Other Jurisdiction of Incorporation Subsidiaries Percentage Ownership MainStreet Bank Virginia 100% MainStreet Community Capital, LLC Virginia 100%

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 3)

-12-31FY2024 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 3) (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File

ARTICLES OF INCORPORATION (AS AMENDED) MAINSTREET BANCSHARES, INC. ARTICLE I NAME

Exhibit 3.1 ARTICLES OF INCORPORATION (AS AMENDED) OF MAINSTREET BANCSHARES, INC. ARTICLE I NAME The name of the Corporation is: MainStreet Bancshares, Inc. ARTICLE II PURPOSES The purpose of the Corporation is to conduct the business of a corporation and bank holding company and to conduct any and all business, including trust business, and to have any and all corporate powers, which are permitte

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 3, 2026 MainStreet Bancshar

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 3, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 20, 2026 MainStreet Banc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 20, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Comm

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 27, 2026 MainStreet Bancs

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 27, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: January 26, 2026 MainStreet

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: January 26, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation)

MainStreet Bancshares Inc. Reports a Profitable 2025 and remains focused on serving the Washington, DC Metropolitan Community Strategic Balance Sheet Management Yields a Healthy Net Interest Margin

Exhibit 99.1 PRESS RELEASE Contact: Billy Freesmeier January 26, 2026 8:00 AM ET Chief of Staff (703) 481-4579 MainStreet Bancshares Inc. Reports a Profitable 2025 and remains focused on serving the Washington, DC Metropolitan Community Strategic Balance Sheet Management Yields a Healthy Net Interest Margin Fairfax, VA., January 26, 2026 – MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the fi

EXHIBIT 99.2

Exhibit 99.2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 12, 2026 MainStreet Bancs

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 12, 2026 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

EXECUTIVE EMPLOYMENT AGREEMENT As Amended and Restated

Exhibit 10.1 EXECUTIVE EMPLOYMENT AGREEMENT As Amended and Restated THIS EXECUTIVE EMPLOYMENT AGREEMENT (the “Agreement”) is made and entered into as of the 18th day of December, 2025, and effective as of the 31st day of December, 2025, by and between MAINSTREET BANK, a Virginia chartered bank (the “Bank”) and wholly owned subsidiary of MainStreet Bancshares, Inc. (“Company”), and Richard A. Vari

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 18, 2025 MainStreet Banc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 18, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Comm

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 15, 2025 MainStreet Banc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 15, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Comm

EXECUTIVE EMPLOYMENT AGREEMENT As Amended and Restated

Exhibit 10.1 EXECUTIVE EMPLOYMENT AGREEMENT As Amended and Restated THIS EXECUTIVE EMPLOYMENT AGREEMENT (the “Agreement”) is made and entered into as of the 5th day of December, 2025 (“Effective Date”), by and between MAINSTREET BANCSHARES, INC., a Virginia chartered company (“Company”) and parent corporation of MAINSTREET BANK, a Virginia chartered bank (the “Bank”), and THOMAS J. CHMELIK (the “E

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 5, 2025 MainStreet Bancs

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 5, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 20, 2025 MainStreet Banc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 20, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Comm

MainStreet Bancshares, Inc. Announces CFO Planned Retirement Bank CFO to Assume Company CFO Title and Responsibilities

Exhibit 99.1 PRESS RELEASE Contact: Billy Freesmeier November 26, 2025, 8:00 AM ET Chief of Staff Desk (703) 481-4579 MainStreet Bancshares, Inc. Announces CFO Planned Retirement Bank CFO to Assume Company CFO Title and Responsibilities Fairfax, VA., November 26, 2025 — MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the Financial Holding Company for MainStreet Bank, announced that Thomas J. C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 21, 2025 MainStreet Banc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 21, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Comm

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended September 30, 2025, as filed with the Securities and Exchange Commission (the “Report”), we hereby certify, pursuant to 18 U.S.C. Section 1350, as

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to to Commission file number: 001-38817 Ma

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 4, 2025 MainStreet Bancs

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 4, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 28, 2025 MainStreet Bancs

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 28, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

MainStreet Bancshares Inc. Reports Another Profitable Quarter Net Income and Earnings Per Share Exceed Market Expectations

Exhibit 99.1 PRESS RELEASE Contact: Billy Freesmeier October 27, 2025 8:00 AM ET Chief of Staff (703) 481-4579 MainStreet Bancshares Inc. Reports Another Profitable Quarter Net Income and Earnings Per Share Exceed Market Expectations Fairfax, VA., October 27, 2025 – MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the financial holding company for MainStreet Bank, reported a net income of $4.52

EXHIBIT 99.2

Exhibit 99.2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: October 27, 2025 MainStreet

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: October 27, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 16, 2025 MainStreet Bancs

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 16, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 14, 2025 MainStreet Bancs

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 14, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 18, 2025 MainStreet Ban

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 18, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Com

EXECUTIVE EMPLOYMENT AGREEMENT RICHARD A. VARI

EXHIBIT 10.2 EXECUTIVE EMPLOYMENT AGREEMENT RICHARD A. VARI THIS EXECUTIVE EMPLOYMENT AGREEMENT (the “Agreement”) is made and entered into as of the 1st day of July 2025 (“Effective Date”), by and between MAINSTREET BANK, a Virginia chartered bank (the “Bank”) and a wholly owned subsidiary of MainStreet Bancshares, Inc. (“Company”), and Richard A. Vari (the “Executive”). This Agreement collectivel

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 27, 2025 MainStreet Bancsh

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 27, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commis

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to to Commission file number: 001-38817 MainStr

Section 1350 Certification *

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended June 30, 2025, as filed with the Securities and Exchange Commission (the “Report”), we hereby certify, pursuant to 18 U.S.C. Section 1350, as adop

Restated Articles of Incorporation

Exhibit 3.1 ARTICLES OF INCORPORATION (AS AMENDED) OF MAINSTREET BANCSHARES, INC. ARTICLE I NAME The name of the Corporation is: MainStreet Bancshares, Inc. ARTICLE II PURPOSES The purpose of the Corporation is to conduct the business of a corporation and bank holding company and to conduct any and all business, including trust business, and to have any and all corporate powers, which are permitte

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 2)

-12-31FY2024 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 2) (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 23, 2025 MainStreet Bancshar

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 23, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

MainStreet Bancshares Inc. Reports Strong Second Quarter Earnings Net Income Climbs on Net Interest Margin Expansion and Strategic Balance Sheet Management

Exhibit 99.1 PRESS RELEASE Contact: Billy Freesmeier July 22, 2025 8:00 AM ET Chief of Staff (703) 481-4579 MainStreet Bancshares Inc. Reports Strong Second Quarter Earnings Net Income Climbs on Net Interest Margin Expansion and Strategic Balance Sheet Management Fairfax, VA., July 22, 2025 – MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the financial holding company for MainStreet Bank, rep

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: July 22, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Co

Investor Presentation dated July 22, 2025

Exhibit 99.2

Regulation FD Disclosure

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 8, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissio

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 7, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissio

MainStreet Bank Promotes Alex Vari to Chief Financial Officer Internal Promotion Signifies the Bank’s Strength and Depth of Leadership

Exhibit 99.1 PRESS RELEASE Contact: Billy Freesmeier July 7, 2025 8:00 AM ET Chief of Staff (703) 481-4579 MainStreet Bank Promotes Alex Vari to Chief Financial Officer Internal Promotion Signifies the Bank’s Strength and Depth of Leadership FAIRFAX, Va., July 7, 2025 - MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the Holding Company for MainStreet Bank, announced the promotion of Alex Vari

Consent of Independent Registered Public Accounting Firm

Exhibit 23.0 Consent of Independent Registered Public Accounting Firm We consent to the incorporation by reference in Registration Statement (No. 333-279618, 333-256477, 333-233078 and 333-233077) on Form S-8 of MainStreet Bancshares, Inc. of our report dated June 20, 2025, relating to our audit of the financial statements and supplemental schedules of the MainStreet Bank 401(k) Plan (the Plan), w

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 1

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 30, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 23, 2025 MainStreet Bancshare

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 23, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to to Commission file number: 001-38817 MainSt

Section 1350 Certification *

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended March 31, 2025, as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as adop

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 6, 2025 MainStreet Bancshares

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 6, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commission

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 22, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commiss

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: April 21, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (C

MainStreet Bancshares Inc. Reports First Quarter Results Expanding Net Interest Margin, Resilient Loan Portfolio and Well Capitalized

Exhibit 99.1 PRESS RELEASE Contact: Billy Freesmeier April 21, 2025 8:00 AM ET Chief of Staff (703) 481-4579 MainStreet Bancshares Inc. Reports First Quarter Results Expanding Net Interest Margin, Resilient Loan Portfolio and Well Capitalized Fairfax, VA., April 21, 2025 — MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the financial holding company for MainStreet Bank, reported first quarter

Investor Presentation dated April 21, 2025

Exhibit 99.2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D. C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.   ) Filed by the Registrant ☒ Filed by a Party other than the Regist

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D. C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.   ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ De

ARS

Annual Report May 2025 Dear Shareholder: The Washington, D.C. metropolitan area is a great place to do business and we are committed to serving all facets of our community. With nine major universities, six resident fortune 500 companies, record-setting convention and tourism numbers, high median incomes and five major sport franchises, our market is robust. And since our market is home to the nat

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 7, 2025 MainStreet Bancshar

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 7, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1)

-12-31FY2024 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1) (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File

Section 1350 Certification

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the annual report on Form 10-K of MainStreet Bancshares, Inc. (the “Company”) for the fiscal year ended December 31, 2024 as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as a

Insider Trading Policies and Procedures

Exhibit 19.0 Policy Statement on Insider Trading and Confidentiality Adopted July 17, 2024 To: All directors, officers, and other employees of, and consultants and other service providers to, the Company. This Policy Statement confirms procedures that such persons at every level must follow, arising from our responsibilities as a public company. MainStreet Bancshares, Inc. and MainStreet Bank (col

RESTATED ARTICLES OF INCORPORATION MAINSTREET BANCSHARES, INC. ARTICLE I NAME

Exhibit 3.1 RESTATED ARTICLES OF INCORPORATION OF MAINSTREET BANCSHARES, INC. ARTICLE I NAME The name of the Corporation is: MainStreet Bancshares, Inc. ARTICLE II PURPOSES The purpose of the Corporation is to conduct the business of a corporation and bank holding company and to conduct any and all business, including trust business, and to have any and all corporate powers, which are permitted to

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-38817 MainStreet Banc

Subsidiaries of the Registrant

EXHIBIT 21.1 Subsidiaries of the Registrant Parent MainStreet Bancshares, Inc. State or Other Jurisdiction of Incorporation Subsidiaries Percentage Ownership MainStreet Bank Virginia 100% MainStreet Community Capital, LLC Virginia 100%

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 27, 2025 MainStreet Banc

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 27, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Comm

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 28, 2025 MainStreet Bancs

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 28, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

Investor Presentation dated January 27, 2025.

Exhibit 99.2

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: January 27, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation)

MainStreet Bancshares Inc. Reports 2024 Results A challenging year ending with strong and stable asset quality and capital

Exhibit 99.1 PRESS RELEASE Contact: Billy Freesmeier January 27, 2025 8:00 AM ET Chief of Staff (703) 481-4579 MainStreet Bancshares Inc. Reports 2024 Results A challenging year ending with strong and stable asset quality and capital Fairfax, VA., January 27, 2025 — MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the financial holding company for MainStreet Bank reported a loss of $9.98 millio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 17, 2025 MainStreet Bancs

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 17, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

Regulation FD Disclosure

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 8, 2025 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commis

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 22, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Comm

Presentation materials, dated November 13, 2024.

Exhibit 99.1

Section 1350 Certification *

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended September 30, 2024, as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 13, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Comm

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to to Commission file number: 001-38817 Ma

JOINT FILING AGREEMENT

EX-99 2 Rule13DJointFilingAgreement.htm JOINT FILING AGREEMENT JOINT FILING AGREEMENT The undersigned hereby agree that this Schedule 13G (the “Schedule 13G”) with respect to the common stock of MainStreet Bancshares, Inc. is, and any additional amendment thereto signed by each of the undersigned shall be, filed on behalf of each undersigned pursuant to and in accordance with the provisions of 13d

MNSB / MainStreet Bancshares, Inc. / WELLINGTON MANAGEMENT GROUP LLP - SEC SCHEDULE 13G Passive Investment

SC 13G/A 1 SEC13GFiling.htm SEC SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1 )* MainStreet Bancshares, Inc. (Name of Issuer) Common Stock (Title of Class of Securities) 56064Y100 (CUSIP Number) September 30, 2024 (Date of Event Which Requires Filing of this Statement) Check the appropria

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 29, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

Investor Presentation dated October 28, 2024.

MainStreet Bancshares Inc. Reports Third Quarter Results Increase in Core Deposits, a High Quality Loan Portfolio and Strong Capital

Exhibit 99.1 PRESS RELEASE Contact: Debra Cope October 28, 2024 8:00 AM ET Director of Corporate Communications Desk (703) 481-4599 Mobile (202) 468-3184 MainStreet Bancshares Inc. Reports Third Quarter Results Increase in Core Deposits, a High Quality Loan Portfolio and Strong Capital Fairfax, VA., October 28, 2024 — MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the financial holding compan

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: October 28, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation)

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 10, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

MainStreet Bancshares Issues Guidance for Third Quarter 2024 Earnings

Exhibit 99.1 MainStreet Bancshares Issues Guidance for Third Quarter 2024 Earnings FAIRFAX, Va., October 10, 2024 – MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the holding company for MainStreet Bank, today issued guidance for its upcoming third quarter earnings. The Company estimates a loss of four cents per common share for the third quarter. During the third quarter, the Company charged

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 21, 2024 MainStreet Bancsh

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 21, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commis

Section 1350 Certification *

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended June 30, 2024, as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as adopt

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to to Commission file number: 001-38817 MainStr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: July 29, 2024 MainStreet Ba

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: July 29, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Co

Investor Presentation dated July 29, 2024.

Exhibit 99.2

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 29, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

MainStreet Bancshares Inc. Reports a Profitable Second Quarter Rise in Core Deposits Fueled an Uptick in Loan Growth

Exhibit 99.1 PRESS RELEASE Contact: Debra Cope July 29, 2024 8:00 AM ET Director of Corporate Communications Desk (703) 481-4599 Mobile (202) 468-3184 MainStreet Bancshares Inc. Reports a Profitable Second Quarter Rise in Core Deposits Fueled an Uptick in Loan Growth FAIRFAX, Va., July 29, 2024 /PRNewswire/ - MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the holding company for MainStreet Ba

Regulation FD Disclosure

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 8, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 1

Consent of Independent Registered Public Accounting Firm

Exhibit 23.0 Consent of Independent Registered Public Accounting Firm We consent to the incorporation by reference in Registration Statement (No. 333-279618, 333-256477, 333-233078 and 333-233077) on Form S-8 of MainStreet Bancshares, Inc. of our report dated June 20, 2024, relating to our audit of the financial statements and supplemental schedules of the MainStreet Bank 401(k) Plan (the Plan), w

MAINSTREET BANCSHARES, INC. as Trustee Dated as of , 202_ SENIOR DEBT SECURITIES TABLE OF CONTENTS

Exhibit 4.3 MAINSTREET BANCSHARES, INC. AND as Trustee INDENTURE Dated as of , 202 SENIOR DEBT SECURITIES TABLE OF CONTENTS Page ARTICLE ONE DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION 1 SECTION 101. Definitions 5 SECTION 102. Compliance Certificates and Opinions 5 SECTION 103. Form of Documents Delivered to Trustee 6 SECTION 104. Acts of Holders 6 SECTION 105. Notices, etc. 6 SECTION

ARTICLES OF INCORPORATION (AS AMENDED) MAINSTREET BANCSHARES, INC. ARTICLE I NAME

Exhibit 3.1 ARTICLES OF INCORPORATION (AS AMENDED) OF MAINSTREET BANCSHARES, INC. ARTICLE I NAME The name of the Corporation is: MainStreet Bancshares, Inc. ARTICLE II PURPOSES The purpose of the Corporation is to conduct the business of a corporation and bank holding company and to conduct any and all business, including trust business, and to have any and all corporate powers, which are permitte

MAINSTREET BANCSHARES, INC. _____________________________, as Trustee Dated as of , 202_

Exhibit 4.4 MAINSTREET BANCSHARES, INC. AND , as Trustee INDENTURE Dated as of , 202 SUBORDINATED DEBT SECURITIES TABLE OF CONTENTS Page ARTICLE ONE DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION SECTION 101. Definitions 1 SECTION 102. Compliance Certificates and Opinions 5 SECTION 103. Form of Documents Delivered to Trustee 6 SECTION 104. Acts of Holders 6 SECTION 105. Notices, etc. 6 SE

As filed with the Securities and Exchange Commission on June 11, 2024

As filed with the Securities and Exchange Commission on June 11, 2024 Registration No.

VIA EDGAR SUBMISSION

VIA EDGAR SUBMISSION June 11, 2024 Securities and Exchange Commission Division of Corporation Finance 100 F.

VIA EDGAR SUBMISSION

VIA EDGAR SUBMISSION June 7, 2024 Securities and Exchange Commission Division of Corporation Finance 100 F.

VIA EDGAR SUBMISSION

VIA EDGAR SUBMISSION June 5, 2024 Securities and Exchange Commission Division of Corporation Finance 100 F.

LETTER

United States securities and exchange commission logo May 31, 2024 Jeff W. Dick Chief Executive Officer MainStreet Bancshares, Inc. 10089 Fairfax Boulevard, Fairfax, VA 22030 Re: MainStreet Bancshares, Inc. Registration Statement on Form S-3 Filed May 22, 2024 File No. 333-279617 Dear Jeff W. Dick: This is to advise you that we have not reviewed and will not review your registration statement. Ple

As filed with the Securities and Exchange Commission on May 22, 2024

As filed with the Securities and Exchange Commission on May 22, 2024 Registration No.

As filed with the Securities and Exchange Commission on May 22, 2024

As filed with the Securities and Exchange Commission on May 22, 2024 Registration No.

Calculation of Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Table Form S-8 (Form Type) MainStreet Bancshares, Inc.

Form of Indenture for Subordinated Indebtedness*

Exhibit 4.4 MAINSTREET BANCSHARES, INC. AND , as Trustee INDENTURE Dated as of , 202 SUBORDINATED DEBT SECURITIES TABLE OF CONTENTS Page ARTICLE ONE DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION SECTION 101. Definitions 1 SECTION 102. Compliance Certificates and Opinions 5 SECTION 103. Form of Documents Delivered to Trustee 6 SECTION 104. Acts of Holders 6 SECTION 105. Notices, etc. 6 SE

Filing Fee Table*

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) MainStreet Bancshares, Inc.

Form of Indenture for Senior Indebtedness*

Exhibit 4.3 MAINSTREET BANCSHARES, INC. AND as Trustee INDENTURE Dated as of , 202 SENIOR DEBT SECURITIES TABLE OF CONTENTS Page ARTICLE ONE DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION 1 SECTION 101. Definitions 5 SECTION 102. Compliance Certificates and Opinions 5 SECTION 103. Form of Documents Delivered to Trustee 6 SECTION 104. Acts of Holders 6 SECTION 105. Notices, etc. 6 SECTION

As filed with the Securities and Exchange Commission on May 17, 2024

As filed with the Securities and Exchange Commission on May 17, 2024 Registration No.

2019 Equity Incentive Plan, as amended.

Exhibit 10.1 MAINSTREET BANCSHARES, INC. 2019 EQUITY INCENTIVE PLAN As amended and restated ARTICLE 1 – GENERAL Section 1.1 Purpose, Effective Date and Term. The purpose of the MainStreet Bancshares, Inc. 2019 Equity Incentive Plan (the “Plan”) is to promote the long-term financial success of MainStreet Bancshares, Inc. and any of its Subsidiaries or future parent or subsidiary corporations, by pr

Amendment to Restated Articles of Incorporation.

EXHIBT 3.1 AMENDMENT TO ARTICLES OF INCORPORATION The Board of Directors of MainStreet Bancshares, Inc. (the “Company”) has duly adopted the following resolution amending Article III.1. of the Articles of Incorporation: RESOLVED, that having determined that an increase in the authorized Common Stock to 15,000,000 shares is in the best interest of the Company and its shareholders, and subject to co

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT -12-31 Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 15, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Co

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to to Commission file number: 001-38817 MainSt

Section 1350 Certification *

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended March 31, 2024, as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as adop

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: April 23, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation)

MainStreet Bancshares Inc. reports a profitable first quarter Strong credit quality and no adverse loan portfolio trends

Exhibit 99.1 PRESS RELEASE Contact: Debra Cope April 22, 2024 8:00 AM ET Director of Corporate Communications Desk (703) 481-4599 Mobile (202) 468-3184 MainStreet Bancshares Inc. reports a profitable first quarter Strong credit quality and no adverse loan portfolio trends FAIRFAX, Va., April 22, 2024 /PRNewswire/ - MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the holding company for MainStr

Corrected Investor Presentation dated April 23, 2024.

Exhibit 99.2

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 23, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commiss

Investor Presentation dated April 22, 2024.

Exhibit 99.2

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 22, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commiss

MainStreet Bancshares Inc. reports a profitable first quarter Strong credit quality and no adverse loan portfolio trends

Exhibit 99.1 PRESS RELEASE Contact: Debra Cope April 22, 2024 8:00 AM ET Director of Corporate Communications Desk (703) 481-4599 Mobile (202) 468-3184 MainStreet Bancshares Inc. reports a profitable first quarter Strong credit quality and no adverse loan portfolio trends FAIRFAX, Va., April 22, 2024 /PRNewswire/ - MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the holding company for MainStr

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: April 22, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (C

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UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D. C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.  )

DEF 14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D. C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.  ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2

Regulation FD Disclosure

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 8, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 25, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commiss

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D. C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.  )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D. C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.  ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☒ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☐ Def

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-38817 MainStreet Banc

Section 1350 Certification

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the annual report on Form 10-K of MainStreet Bancshares, Inc. (the “Company”) for the fiscal year ended December 31, 2023 as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as a

Subsidiaries of the Registrant

EXHIBIT 21.1 Subsidiaries of the Registrant Parent MainStreet Bancshares, Inc. State or Other Jurisdiction of Incorporation Subsidiaries Percentage Ownership MainStreet Bank Virginia 100% MainStreet Community Capital, LLC Virginia 100%

Policy Relating to the Recovery of Erroneously Awarded Compensation

Exhibit 97.1 MAINSTREET BANCSHARES, INC. Policy for the Recovery of Erroneously Awarded Compensation The Board of Directors (the “Board”) of MainStreet Bancshares, Inc. (the “Company”) has determined that it is in the best interests of the Company and its shareholders to adopt this Policy for the Recovery of Erroneously Awarded Compensation (this “Policy”), which provides for the recovery of certa

Regulation FD Disclosure

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 4, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

Regulation FD Disclosure, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 22, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Comm

MainStreet Bank Appoints Ali Manouchehri to Board of Directors Digital Technology Expert Brings Extensive Federal Contracting Experience to Role at Leading Community Bank

Exhibit 99.1 MainStreet Bank Appoints Ali Manouchehri to Board of Directors Digital Technology Expert Brings Extensive Federal Contracting Experience to Role at Leading Community Bank FAIRFAX, Va., February 22, 2024 /PRNewswire/ - MainStreet Bancshares, Inc. (Nasdaq: MNSB), parent company of MainStreet Bank, announces the appointment of Ali Reza Manouchehri, a digital technology expert with extens

MNSB / MainStreet Bancshares, Inc. / ALLIANCEBERNSTEIN L.P. - SEC SCHEDULE 13G Passive Investment

SC 13G/A 1 SEC13GFiling.htm SEC SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1 )* MainStreet Bancshares Inc (Name of Issuer) Common Stock (Title of Class of Securities) 56064Y100 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate

MNSB / MainStreet Bancshares, Inc. / BANC FUNDS CO LLC - NONE Passive Investment

Schedule 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* MAINSTREET BANKSHARES INC (Name of Issuer) COMMON STOCK (Title of Class of Securities) 56064Y100 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuan

MNSB / MainStreet Bancshares, Inc. / WELLINGTON MANAGEMENT GROUP LLP - SEC SCHEDULE 13G Passive Investment

SC 13G 1 SEC13GFiling.htm SEC SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* MainStreet Bancshares, Inc. (Name of Issuer) Common Stock (Title of Class of Securities) 56064Y100 (CUSIP Number) December 29, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate bo

MNSB / MainStreet Bancshares, Inc. / BlackRock Inc. Passive Investment

SC 13G/A 1 us56064y1001020724.txt us56064y1001020724.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 1) MAINSTREET BANCSHARES INC - (Name of Issuer) Common Stock - (Title of Class of Securities) 56064Y100 - (CUSIP Number) January 31, 2024 - (Date of Event Which Requires Filing of this Statement) Check the appropria

MNSB / MainStreet Bancshares, Inc. / BlackRock Inc. Passive Investment

SC 13G 1 us56064y1001013124.txt us56064y1001013124.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: ) MAINSTREET BANCSHARES INC - (Name of Issuer) Common Stock - (Title of Class of Securities) 56064Y100 - (CUSIP Number) December 31, 2023 - (Date of Event Which Requires Filing of this Statement) Check the appropriate

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 23, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

Investor Presentation dated January 22, 2024.

Exhibit 99.2

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: January 22, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation)

MainStreet Bancshares Inc. Delivered Consistent 2023 Earnings Despite Market Turmoil Year-End and Fourth Quarter Results Underscore Steady Progress in Challenging Environment

Exhibit 99.1 PRESS RELEASE Contact: Debra Cope January 22, 2024 8:00 AM ET Director of Corporate Communications Desk (703) 481-4599 Mobile (202) 468-3184 MainStreet Bancshares Inc. Delivered Consistent 2023 Earnings Despite Market Turmoil Year-End and Fourth Quarter Results Underscore Steady Progress in Challenging Environment FAIRFAX, Va., January 22, 2024 /PRNewswire/ - MainStreet Bancshares, In

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 8, 2024 MainStreet Bancsh

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 8, 2024 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commis

LETTER

United States securities and exchange commission logo December 13, 2023 Thomas J. Chmelik Senior Executive Vice President and Chief Financial Officer MainStreet Bancshares, Inc. 10089 Fairfax Boulevard Fairfax, VA 22030 Re: MainStreet Bancshares, Inc. Form 10-K For the Fiscal Year Ended December 31, 2022 File No. 001-38817 Dear Thomas J. Chmelik: We have completed our review of your filings. We re

VIA EDGAR SUBMISSION

VIA EDGAR SUBMISSION December 7, 2023 Michael Henderson Securities and Exchange Commission Division of Corporation Finance Office of Finance Washington, D.

LETTER

United States securities and exchange commission logo December 5, 2023 Thomas J. Chmelik Senior Executive Vice President and Chief Financial Officer MainStreet Bancshares, Inc. 10089 Fairfax Boulevard Fairfax, VA 22030 Re: MainStreet Bancshares, Inc. Form 10-K For the Fiscal Year Ended December 31, 2022 Form 10-Q For the Fiscal Quarter Ended September 30, 2023 File No. 001-38817 Dear Thomas J. Chm

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K -12-31 CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 16, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation

Amended and Restated Bylaws of MainStreet Bancshares, Inc., effective as of November 15, 2023.

EXHIBIT 3.1 MAINSTREET BANCSHARES, INC. BYLAWS (As Amended and Restated on November 15, 2023) ARTICLE I Meetings of Shareholders Section 1. Places of Meetings. All meetings of the shareholders shall be held at such place, either within or without the Commonwealth of Virginia, as may, from time to time, be fixed by the Board of Directors. The Board of Directors may also hold any meeting of sharehol

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to to Commission file number: 001-38817 Ma

Section 1350 Certification *

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended September 30, 2023, as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 23, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 24, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: October 23, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation)

Investor Presentation dated October 23, 2023.

Exhibit 99.2

MainStreet Bancshares, Inc., Reports Solid Earnings for 3rd Quarter 2023 Net Income Totals $6.3 Million for the Quarter Ended September 30

Exhibit 99.1 PRESS RELEASE Contact: Debra Cope October 23, 2023, 8:00 AM ET Director of Corporate Communications Desk (703) 481-4599 Mobile (202) 468-3184 MainStreet Bancshares, Inc., Reports Solid Earnings for 3rd Quarter 2023 Net Income Totals $6.3 Million for the Quarter Ended September 30 FAIRFAX, Va., October 23, 2023 /PRNewswire/ - MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the hold

MainStreet Bank Inaugurates Its Avenu Software as a Service (SaaS) Technology with Its First Client, SafariPay

Exhibit 99.1 PRESS RELEASE Contact: Debra Cope Director of Corporate Communications (202) 468-3814 MainStreet Bank Inaugurates Its Avenu Software as a Service (SaaS) Technology with Its First Client, SafariPay FAIRFAX, VA October 18, 2023 /PR NEWSWIRE/ – MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the holding company for MainStreet Bank, announces the launch of Avenu’s fully integrated Sof

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: October 18, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation)

Regulation FD Disclosure

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 10, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 19, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to to Commission file number: 001-38817 MainStr

Section 1350 Certification *

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended June 30, 2023, as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as adopt

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: July 24, 2023 MainStreet Ba

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): Date: July 24, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Co

MainStreet Bancshares, Inc., Reports Continued Strong Financial Performance for 2nd Quarter 2023 Net Interest Margin Continues to Outperform Most Peers

Exhibit 99.1 PRESS RELEASE Contact: Debra Cope July 24, 2023, 8:00 AM ET Director of Corporate Communications (703) 481-4599 MainStreet Bancshares, Inc., Reports Continued Strong Financial Performance for 2nd Quarter 2023 Net Interest Margin Continues to Outperform Most Peers FAIRFAX, Va., July 24, 2023 /PRNewswire/ - MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the holding company for Main

Investor Presentation dated July 24, 2023

Exhibit 99.2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 20, 2023 MainStreet Bancshar

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 20, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 10, 2023 MainStreet Bancshar

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 10, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 1

Consent of Independent Registered Public Accounting Firm

Exhibit 23.0 Consent of Independent Registered Public Accounting Firm We consent to the incorporation by reference in Registration Statement (No. 333-256477, 333-233078 and 333-233077) on Form S-8 of MainStreet Bancshares, Inc. of our report dated June 16, 2023, relating to our audit of the financial statements and supplemental schedules of the MainStreet Bank 401(k) Plan (the Plan), which appears

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 18, 2023 MainStreet Bancshare

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 18, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to to Commission file number: 001-38817 MainSt

Section 1350 Certification *

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended March 31, 2023, as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as adop

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 24, 2023 MainStreet Bancsha

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 24, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commiss

MainStreet Bancshares, Inc., Reports Record Earnings for 1st Quarter 2023 Steady Loan and Deposit Growth Fuel 8% Rise in Quarter-to-Quarter Net Income

Exhibit 99.1 PRESS RELEASE Contact: Debra Cope April 17, 2023, 8:00 AM ET Director of Corporate Communications (703) 481-4599 MainStreet Bancshares, Inc., Reports Record Earnings for 1st Quarter 2023 Steady Loan and Deposit Growth Fuel 8% Rise in Quarter-to-Quarter Net Income FAIRFAX, Va., April 17, 2023 /PRNewswire/ - MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the holding company for Mai

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 17, 2023 MainStreet Bancsha

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 17, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commiss

Investor Presentation dated April 17, 2023.

Exhibit 99.2

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

DEF 14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A (Rule 14a-101) INFORMATION REQUIRED IN PROXY STATEMENT SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, fo

ARS

2022 Annual Report MainStreet Bancshares, Inc.May 2023 Dear Shareholder, At MainStreet Bank, we’ve always operated with three core principles: 1) focus on what we do best, which means don’t try to be all things to all people; 2) lead with high-quality service, not price; and 3) conservatively anticipate and prepare for market changes. The saying goes that when you try to be all things to all peopl

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 3, 2023 MainStreet Bancshar

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 3, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

Section 1350 Certification

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the annual report on Form 10-K of MainStreet Bancshares, Inc. (the “Company”) for the fiscal year ended December 31, 2022 as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as a

Form of Restricted Stock Award Agreement (incorporated by reference to Exhibit 10.10 to the Company’s Form 10-K filed on March 23, 2023).

EXHIBIT 10.10 RESTRICTED STOCK AWARD AGREEMENT MAINSTREET BANCSHARES, INC. 2019 EQUITY INCENTIVE PLAN This restricted stock award agreement (“Restricted Stock Award” or “Agreement”) is and will be subject in every respect to the provisions of the 2019 Equity Incentive Plan (the “ Plan ”) of MainStreet Bancshares, Inc. (the “Company ”) which are incorporated herein by reference and made a part here

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO Commission File Number 001-38817 MainStreet Banc

Subsidiaries of the Registrant

EXHIBIT 21.1 Subsidiaries of the Registrant Parent MainStreet Bancshares, Inc. State or Other Jurisdiction of Incorporation Subsidiaries Percentage Ownership MainStreet Bank Virginia 100% MainStreet Community Capital, LLC Virginia 100%

MNSB / MainStreet Bancshares Inc / BANC FUNDS CO LLC - NONE Passive Investment

Schedule 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 02)* MAINSTREET BANKSHARES INC (Name of Issuer) COMMON STOCK (Title of Class of Securities) 56064Y100 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursua

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 16, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Comm

MNSB / MainStreet Bancshares Inc / EJF Capital LLC Passive Investment

SC 13G/A 1 ff170914013ga2-mainstreet.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2) Mainstreet Bancshares, Inc. (Name of Issuer) Common Stock, par value $4.00 per share (Title of Class of Securities) 56064Y100 (CUSIP Number) December 31, 2022 (Date of Event which Requires Filing of this Statement)

MNSB / MainStreet Bancshares Inc / ALLIANCEBERNSTEIN L.P. - SEC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* MainStreet Bancshares Inc (Name of Issuer) Common Stock (Title of Class of Securities) 56064Y100 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which thi

MNSB / MainStreet Bancshares Inc / BANC FUNDS CO LLC - NONE Passive Investment

Schedule 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1)* MAINSTREET BANKSHARES INC (Name of Issuer) COMMON STOCK (Title of Class of Securities) 56064Y100 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuan

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 23, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

MainStreet Bancshares, Inc. Achieves Record Results for 2022 Company’s Net Income Climbs 20% to $26.7 Million; NIM Reaches 4.19%

EX-99.1 2 ex458731.htm EXHIBIT 99.1 Exhibit 99.1 PRESS RELEASE Contact: Debra Cope January 23, 2023, 8:00 AM ET Director of Corporate Communications (703) 481-4599 MainStreet Bancshares, Inc. Achieves Record Results for 2022 Company’s Net Income Climbs 20% to $26.7 Million; NIM Reaches 4.19% FAIRFAX, Va., Jan. 23, 2023 /PRNewswire/ - MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the holding

Investor Presentation dated January 23, 2023.

Exhibit 99.2

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 19, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

Regulation FD Disclosure

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 9, 2023 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commis

Form of Indemnification Agreement with each of Jeff W. Dick, Thomas J. Chmelik and Abdul Hersiburane (incorporated by reference to Exhibit 10.1 to the Company's Form 8-K filed on November 21, 2022)

EXHIBIT 10.1 FORM OF EXECUTIVE OFFICER INDEMNIFICATION AGREEMENT THIS INDEMNIFICATION AGREEMENT (the ?Agreement?) is made and entered into as of [?], 2022, between MAINSTREET BANCSHARES, INC., a Virginia corporation (the ?Company?), and the undersigned Executive Officer of the Company (?Indemnitee?). WHEREAS, highly competent persons have become more reluctant to serve corporations as officers or

Employment Agreement with Abdulhamid Hersiburane (incorporated by reference to Exhibit 10.2 to the Company’s Form 8-K filed on November 21, 2022)

EXHIBIT 10.2 EXECUTIVE EMPLOYMENT AGREEMENT THIS EXECUTIVE EMPLOYMENT AGREEMENT (the ?Agreement?) is made and entered into as of the 17th day of November 2022, by and between MAINSTREET BANK, a Virginia chartered bank (the ?Bank?) and a wholly owned subsidiary of MainStreet Bancshares, Inc. (?Company?), and Abdul Hersiburane (the ?Executive?). This Agreement collectively refers to the Bank and the

Bylaws (incorporated by reference to Exhibit 3.1 to the Company’s Form 8-K filed on November 16, 2023)

EXHIBIT 3.1 MAINSTREET BANCSHARES, INC. BYLAWS (As Amended and Restated on November 16, 2022) ARTICLE I Meetings of Shareholders Section 1. Places of Meetings. All meetings of the shareholders shall be held at such place, either within or without the Commonwealth of Virginia, as may, from time to time, be fixed by the Board of Directors. The Board of Directors may also hold any meeting of sharehol

Regulation FD Disclosure, Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Other Events

-12-31 UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 16, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to to Commission file number: 001-38817 Ma

Section 1350 Certification *

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended September 30, 2022, as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as

Regulation FD Disclosure

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 24, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 24, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

MainStreet Bancshares, Inc. Reports Strong Earnings Widening net interest margin fueled record financial performance as measured by multiple 3rd quarter 2022 key metrics:

Exhibit 99.1 PRESS RELEASE Contact: Debra Cope October 17, 2022, 8:00 AM ET Director of Corporate Communications (703) 481-4599 MainStreet Bancshares, Inc. Reports Strong Earnings Widening net interest margin fueled record financial performance as measured by multiple 3rd quarter 2022 key metrics: ? 1.70% Return on average assets ? 16.13% Return on average equity ? 4.14% Net interest margin ? $0.9

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 17, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commi

Investor Presentation dated October 17, 2022.

Exhibit 99.2

Section 1350 Certification *

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended June 30, 2022, as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as adopt

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to to Commission file number: 001-38817 MainStr

Regulation FD Disclosure

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 11, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commis

MainStreet Bancshares Announces Formation of Community Development Subsidiary MainStreet Community Capital Aims to Drive Investment to Low-Income Communities

Exhibit 99.1 MainStreet Bancshares Announces Formation of Community Development Subsidiary MainStreet Community Capital Aims to Drive Investment to Low-Income Communities FAIRFAX, VIRGINIA, August 10, 2022 ? The board of directors of MainStreet Bancshares Inc. announced the formation of MainStreet Community Capital, its new community development subsidiary. MainStreet Community Capital?s focus is

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 10, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commis

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 3, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commiss

Investor Presentation dated July 25, 2022.

Exhibit 99.2

MainStreet Bancshares, Inc. Reports Strong Net Income as Interest Rates Rise

Exhibit 99.1 PRESS RELEASE Contact: Jeff W. Dick, Chairman & CEO July 25, 2022, 8:00 AM ET (703) 481-4567 MainStreet Bancshares, Inc. Reports Strong Net Income as Interest Rates Rise Fairfax, Virginia ? July 25, 2022 - MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the holding company for MainStreet Bank, said its net interest margin widened as rates climbed in recent months, driving strong n

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 25, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 22, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissi

Regulation FD Disclosure

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 6, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissio

Consent of Independent Registered Public Accounting Firm

Exhibit 23 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in the Registration Statements on Form S-3 (No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K FOR ANNUAL REPORTS OF EMPLOYEE STOCK PURCHASE, SAVINGS AND SIMILAR PLANS PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 (Mark One) ? ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 1

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 26, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissio

MainStreet Bank Promotes Tom Floyd to Chief Lending Officer Five-Year Veteran of Bank Oversees Growing $1.4 Billion Loan Portfolio

Exhibit 99.1 PRESS RELEASE Contact: Debra Cope May 26, 2022 (202) 468-3814 MainStreet Bank Promotes Tom Floyd to Chief Lending Officer Five-Year Veteran of Bank Oversees Growing $1.4 Billion Loan Portfolio Fairfax, Virginia ? May 26, 2022 - MainStreet Bancshares, Inc. (Nasdaq: MNSB & MNSBP), the holding company for MainStreet Bank, announced it has promoted Tom Floyd to Chief Lending Officer, entr

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 18, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissio

Section 1350 Certification *

Exhibit 32.0 CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 In connection with the Quarterly Report on Form 10-Q of MainStreet Bancshares, Inc. (the “Company”) for the quarter ended March 31, 2022, as filed with the Securities and Exchange Commission (the “Report”), I hereby certify, pursuant to 18 U.S.C. Section 1350, as adop

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UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 10, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commissio

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UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 20, 2022 MainStreet Bancshares, Inc. (Exact name of Registrant as Specified in Its Charter) Virginia 001-38817 81-2871064 (State or Other Jurisdiction of Incorporation) (Commiss

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