Results of Operations and Financial Condition. Earnings Release On July 21, 2026, Mercantile Bank Corporation (the “Company”) issued a press release announcing earnings and other financial results for the quarter ended June 30, 2026. A copy of the press release is furnished as Exhibit 99.1 to this report and incorporated here by reference.

Results of Operations and Financial Condition. Earnings Release On April 21, 2026, Mercantile Bank Corporation (the “Company”) issued a press release announcing earnings and other financial results for the quarter ended March 31, 2026. A copy of the press release is furnished as Exhibit 99.1 to this report and incorporated here by reference.

Adoption of a new bonus plan for executive officers.

Results of Operations and Financial Condition. Earnings Release On January 20, 2026, Mercantile Bank Corporation (the “Company”) issued a press release announcing earnings and other financial results for the quarter and year ended December 31, 2025. A copy of the press release is furnished as Exhibit 99.1 to this report and incorporated here by reference.

Entry into a Material Definitive Agreement On December 24, 2025, Mercantile Bank Corporation, a Michigan corporation (“Mercantile”) entered into a Credit Agreement (the “Credit Agreement”) with U.S. Bank National Association, a national banking association. The Credit Agreement is for a $30.0 million term loan to fund the purchase price and related expenses of the Merger (defined below) and for working capital purposes. The term loan bears interest at an annual rate equal to 1.70% plus the gr…

are qualified in their entirety by the full text of the Credit Agreement, which is filed as Exhibit 10.1 hereto and incorporated herein by reference.

are qualified in their entirety by the full text of the Credit Agreement, which is filed as Exhibit 10.1 hereto and incorporated herein by reference.

Other Events On December 31, 2025, Mercantile issued a press release announcing the completion of its previously announced acquisition of Eastern Michigan Financial Corporation, a Michigan corporation (“EFIN”), and its wholly owned banking subsidiary, Eastern Michigan Bank, headquartered in Crosswell, Michigan, in accordance with the Agreement and Plan of Merger, as amended (the “Merger Agreement”) by and between Mercantile, EFIN, and Shamrock Merger Sub LLC, a wholly-owned special purpose su…

Director — Steve Schweihofer: Appointment of Steve Schweihofer as a director to fill the vacancy on the board.

Other Events On December 19, 2025, Eastern Michigan Financial Corporation (“EFIN”) held a special meeting of shareholders (the “Special Meeting”) to approve the Agreement and Plan of Merger, dated as of July 22, 2025, as amended by the First Amendment, dated October 5, 2025 (the “Merger Agreement”), by and among Mercantile Bank Corporation (“Mercantile”), Shamrock Merger Sub LLC, and EFIN. EFIN disclosed that at the Special Meeting, shareholders of EFIN voted to approve EFIN’s proposed merger…

Other Events As previously announced, on July 22, 2025, Mercantile Bank Corporation (“Mercantile”) and Eastern Michigan Financial Corporation (“Eastern”) entered into an Agreement and Plan of Merger (as amended by the First Amendment dated October 5, 2025, the “Merger Agreement”), pursuant to which Eastern will merge with and into Shamrock Merger Sub LLC, a wholly-owned acquisition subsidiary of Mercantile (the “Merger Sub”), with the Merger Sub as the surviving entity. Immediately thereafter…

Results of Operations and Financial Condition. Earnings Release On October 21, 2025, Mercantile Bank Corporation (the “Company”) issued a press release announcing earnings and other financial results for the quarter ended September 30, 2025. A copy of the press release is furnished as Exhibit 99.1 to this report and incorporated here by reference.

Results of Operations and Financial Condition. Earnings Release On July 22, 2025, Mercantile Bank Corporation (the “Company”) issued a press release announcing earnings and other financial results for the quarter ended June 30, 2025. A copy of the press release is furnished as Exhibit 99.1 to this report and incorporated here by reference.

Entry into a Material Definitive Agreement. On July 22, 2025, Mercantile Bank Corporation (“Mercantile”) and Eastern Michigan Financial Corporation (“EFIN”), entered into an Agreement and Plan of Merger (the “Merger Agreement”), pursuant to which EFIN will merge with and into an acquisition subsidiary of Mercantile, with the acquisition subsidiary as the surviving corporation (the “Merger”). Following the Merger, Mercantile will operate for a period of time as a two-bank holding company. The…

Results of Operations and Financial Condition. Earnings Release On April 22, 2025, Mercantile Bank Corporation (the “Company”) issued a press release announcing earnings and other financial results for the quarter ended March 31, 2025. A copy of the press release is furnished as Exhibit 99.1 to this report and incorporated here by reference.

Adoption of a new bonus plan for executive officers.

The filing describes the details of restricted stock grants to executive officers, which is a routine compensation matter.

Results of Operations and Financial Condition. Earnings Release On January 21, 2025, Mercantile Bank Corporation (the “Company”) issued a press release announcing earnings and other financial results for the quarter and year ended December 31, 2024. A copy of the press release is furnished as Exhibit 99.1 to this report and incorporated here by reference.

Adoption of a new nonqualified deferred compensation plan with no impact on current management or directors.

Results of Operations and Financial Condition. Earnings Release On October 15, 2024, Mercantile Bank Corporation (the “Company”) issued a press release announcing earnings and other financial results for the quarter ended September 30, 2024. A copy of the press release is furnished as Exhibit 99.1 to this report and incorporated here by reference.

Results of Operations and Financial Condition. Earnings Release On July 16, 2024, Mercantile Bank Corporation (the “Company”) issued a press release announcing earnings and other financial results for the quarter ended June 30, 2024. A copy of the press release is furnished as Exhibit 99.1 to this report and incorporated here by reference.

Adoption of a bonus plan for executive officers.

Results of Operations and Financial Condition. Earnings Release On April 16, 2024, Mercantile Bank Corporation (the “Company”) issued a press release announcing earnings and other financial results for the quarter ended March 31, 2024. A copy of the press release is furnished as Exhibit 99.1 to this report and incorporated here by reference.

Director — Nelson F. Sanchez: Appointment of Nelson F. Sanchez as a new Director and his inclusion in various committees.

Results of Operations and Financial Condition. Earnings Release On January 16, 2024, Mercantile Bank Corporation (the “Company”) issued a press release announcing earnings and other financial results for the quarter and year ended December 31, 2023. A copy of the press release is furnished as Exhibit 99.1 to this report and incorporated here by reference.