Md. Code, Labor and Employment § 3-1610

(a) In this section, “complaint” includes a written or oral complaint, claim, or assertion of right by a covered employee regarding the payment of wages under this subtitle that is made to:

(1) the employer or a supervisor, manager, or foreman employed by the employer whether it is made through the employer’s internal grievance process or otherwise; or

(2) the Commissioner or an authorized representative of the Commissioner.

(b) (1) An employer may not:

(i) pay or agree to pay less than the wage required under this subtitle;

(ii) hinder or delay the Commissioner or an authorized representative of the Commissioner in the enforcement of this subtitle;

(iii) take adverse action against a covered employee because the covered employee:

1. makes a complaint that the covered employee has not been paid in accordance with this subtitle;

2. brings an action under this subtitle or a proceeding that relates to the subject of this subtitle; or

3. has testified in an action under this subtitle or a proceeding related to the subject of this subtitle; or

(iv) violate any other provision of this subtitle.

(2) Adverse action prohibited under paragraph (1) of this subsection includes:

(i) discharge;

(ii) demotion;

(iii) threatening the covered employee with discharge or demotion; and

(iv) any other retaliatory action that results in a change to the terms or conditions of employment that would dissuade a reasonable covered employee from making a complaint, bringing an action, or testifying in an action under this subtitle.

(c) A covered employee may not:

(1) make a groundless or malicious complaint to the Commissioner or an authorized representative of the Commissioner;

(2) in bad faith, bring an action under this subtitle or a proceeding related to the subject of this subtitle; or

(3) in bad faith, testify in an action under this subtitle or a proceeding related to the subject of this subtitle.

(d) A person who violates any provision of this section is guilty of a misdemeanor and on conviction is subject to a fine not exceeding $1,000.

(e) An employer may not be convicted under this section unless the evidence demonstrates that the employer had knowledge of the relevant complaint, testimony, or action for which the prosecution for retaliation is sought.