MainStreet Bancshares, Inc.

Item 8.01 Other Events. On August 21, 2026, the Board of Directors of MainStreet Bancshares, Inc. announced the declaration of a quarterly cash dividend on the outstanding shares of the Company’s 7.50% Series A Fixed-Rate Non-Cumulative Perpetual Preferred Stock, par value $1.00 per share (the “Series A Preferred Stock”). On September 15 and 25, 2020, the Company issued an aggregate of 1,150,000 depositary shares (the “Depositary Shares”), each representing a 1/40th ownership interest in a share of the Series A Preferred Stock, with a liquidation preference of $1,000 per share of Series A Preferred Stock (equivalent to $25 per Depositary Share), which represents $28,750,000 in aggregate liquidation preference. The declared cash dividend equated to approximately $0.47 per Depositary Share, or $18.75 per share of Series A Preferred Stock outstanding. The cash dividend is payable on September 30, 2026, to shareholders of record as of the close of business on September 15, 2026. When, as, and if declared by the Board of Directors, future dividend payment dates on the Series A Preferred Stock and associated Depositary Shares will be payable quarterly, in arrears, on March 30, June 30, September 30 and December 30 of each year. The Company’s Depositary Shares trade on the Nasdaq Capital Market under the symbol “MNSBP.” The information furnished under Item 8.01 of this Current Report on Form 8-K shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, and it shall not be deemed incorporated by reference in any filing under the Exchange Act, or the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such filing to this Form 8-K.