Md. Code, Labor and Employment § 3–1102

To establish a lien for unpaid wages under § 3–1104 of this subtitle, an employee shall first provide written notice to an employer that:

(1) is served on the employer within the statute of limitations period under § 5–101 of the Courts Article;

(2) is personally served in accordance with Maryland Rule 2–121; and

(3) contains the information required by the Commissioner under § 3–1110 of this subtitle to provide the employer with adequate notice of the wages claimed and the property against which the lien for unpaid wages is sought.