MERCANTILE BANK CORP

The following words have the following meanings unless a different meaning is plainly required by the context:

2.1 "Board" means the Board of Directors of the Company.

**2.2 "Code"**means the Internal Revenue Code of 1986, as it may be amended from time to time, and the rules and regulations promulgated thereunder.

2.3 "Committee" means the Compensation Committee of the Board or such other committee as the Board may from time to time designate to administer the Plan.

2.4 "Common Stock" means the Company's common stock.

2.5 "Company" means Mercantile Bank Corporation, a Michigan corporation, and its successors and assigns.

2.6 "Corporate Transaction" means a merger, consolidation, acquisition of property or stock, separation, reorganization or other corporate event described in Section 424 of the Code.

2.7 "Employee" means any person who renders services to the Company or one of its Subsidiaries as an employee pursuant to an employment relationship with such employer.

2.8 "Election Form" means a notice (in a form approved by the Committee) that an Eligible Employee must complete to participate in the Plan and authorize payroll deductions to be made on the Eligible Employee's behalf under the Plan.

2.9 "Eligible Employees" means, unless otherwise determined by the Committee in a manner that is consistent with Section 423 of the Code, all present and future active full-time Employees and part-time Employees, excluding any temporary employees, interns, and officers subject to Section 16 of the Securities Exchange Act of 1934, as amended.

2.10 "Fair Market Value" as of any Stock Purchase Date means the consolidated closing bid price of the Common Stock reported on The Nasdaq Stock Market (or other stock exchange or quotation system on which the Company's Common Stock may be traded on the date in question) on such Stock Purchase Date or, if such Stock Purchase Date is not a trading day, the most recent date on which shares of Common Stock were traded on The Nasdaq Stock Market (or such other stock exchange or quotation system). If the Company's Common Stock is not listed on The Nasdaq Stock Market, or another stock exchange or quotation system on the Stock Purchase Date in question, the Fair Market Value shall be determined by any means deemed fair and reasonable by the Committee, which determination shall be final and binding on all parties.

2.11 "Option Period" means each calendar quarter, beginning on the first day of each such calendar quarter and ending on the last day of such calendar quarter. The initial Option Period begins on July 1, 2025.

2.12 "Participant" means an Eligible Employee who has elected to participate in the Plan in accordance with Section 6.1 below.

2.13 "Payroll Deduction Account" means the account established on behalf of a Participant pursuant to Section 7.1 below, to which his or her payroll deductions shall be credited.

2.14 "Permanent Disability" or**"Disability"** means an inability of a Participant to perform his or her employment duties due to physical or mental disability sufficient for the Participant to qualify for disability benefits under the general benefits policies of the Company and in effect from time to time.

2.15 "Plan" means the Mercantile Bank Corporation Employee Stock Purchase Plan of 2025 as set forth herein, as it may be amended from time to time.

2.16 "Purchase Price" means the purchase price for a share of Common Stock to be paid by a Participant on a Stock Purchase Date, as determined under Section 8.1 below.

2.17 "Retirement" means the voluntary termination of all employment by a Participant such that the Participant would qualify for retirement benefits from the Company or a Subsidiary under applicable retirement policies in effect from time to time.

2.18 "Share Account" means the book-entry account established on behalf of a Participant pursuant to Section 8.2 below, to which shares of Common Stock purchased under the Plan shall be credited.

2.19 "Stock Purchase Date" means a date on which shares of Common Stock are purchased pursuant to the Plan. Unless otherwise determined by the Committee, the Stock Purchase Date shall be the last working day of each Option Period during the term of the Plan.

2.20 "Subsidiary" means any corporation or other entity of which 50% or more of the outstanding voting stock or voting ownership interest is directly or indirectly owned or controlled by the Company or by one or more Subsidiaries of the Company. The term "Subsidiary" includes present and future Subsidiaries of the Company.

SECTION 3