Maryland Code, Labor and Employment § 5-604

(a)(1) An employer or other person may not discharge or otherwise discriminate against an employee on the basis of information gained through participation of the employee in group medical coverage.

(2) This title does not prevent an employer from using medical information that:

(1) files a complaint under or related to this title;

(2) brings an action under this title or a proceeding under or related to this title or causes the action or proceeding to be brought;

(3) has testified or will testify in an action under this title or a proceeding under or related to this title;

(4) exercises, for the employee or another, a right under this title; or

(5) is an essential worker who files a complaint or exercises a right under § 3-1704 of this article.

(2) An employee shall file a complaint under this subsection within 30 days after the alleged discrimination occurs.

(d)(1) On receipt of a complaint under subsection (c) of this section, the Commissioner may investigate.

(2) If, after investigation, the Commissioner determines that an employer or other person has violated subsection (a) or (b) of this section, the Commissioner shall file a complaint to enjoin the violation, to reinstate the employee to the former position with back pay, or for other appropriate relief in the circuit court for:

(3) Within 90 days after the Commissioner receives a complaint, the Commissioner shall notify the employee of the determination under this subsection.