Maryland Code, Land Use § 16-202

(1) serve as the sole bargaining agent for the unit in collective bargaining; and

(2) except as provided in subsection (d) of this section, represent all employees in the bargaining unit fairly and without discrimination.

(d)(1) The exclusive representative may require an employee who does not pay membership dues or equivalent fees to pay:

(2) Failure by the employee to pay the costs and fees required under paragraph (1) of this subsection shall relieve the exclusive representative of any further responsibility to the employee.

(3) A dispute concerning the reasonableness of the costs and fees imposed under paragraph (1) of this subsection shall be submitted to the labor relations administrator in accordance with the procedures established under § 16-218 of this subtitle for unfair labor practices.

(e)(1) An exclusive representative's duty of fair representation owed to a public employee who is in the bargaining unit shall be limited to the negotiation and enforcement of the terms of the collective bargaining agreement with the public employer.

(2) Nothing in this subsection may be construed to limit an employee organization from providing only to the organization's members legal, economic, or job-related services or benefits outside the collective bargaining agreement.