Maryland Code, Labor and Employment § 3-1107

(a) A contract between an employee and an employer may not waive or require the employee to waive the right to seek the establishment of a lien for unpaid wages under this subtitle.

(b) A provision in an executory contract between an employer and an employee that conditions payment of wages to the employee on receipt by the employer of a payment from a property owner or a third party may not abrogate or waive the right of an employee to seek the establishment of a lien for unpaid wages under this subtitle.

(c) A provision of a contract that violates this section is void as against the public policy of the State.