Md. Code, Family Law § 5–3A–14

(a) Within 5 days after a petition for guardianship of a child is filed with a court, the clerk shall send a copy of the petition and notice of filing to:

(1) each of the child’s living parents who has not waived the right to notice; and

(2) each living parent’s attorney of record.

(b) Notice under this section shall be by first-class mail.

(c) Notice to a parent under this section shall be sent to a parent’s last address known to the court.