Md. Code, Family Law § 10-344

(a) When a support order or income withholding order issued in another state or a foreign support order is registered, the registering tribunal of this State shall notify the nonregistering party. Notice must be given by first–class, certified, or registered mail or by any means of personal service authorized by the law of this State. The notice must be accompanied by a copy of the registered order and the documents and relevant information accompanying the order.

(b) A notice must inform the nonregistering party:

(1) that a registered order is enforceable as of the date of registration in the same manner as an order issued by a tribunal of this State;

(2) that a hearing to contest the validity or enforcement of the registered order must be requested within 20 days after the date of mailing or personal service of the notice unless the registered order is under § 10–360 of this subtitle;

(3) that failure to contest the validity or enforcement of the registered order in a timely manner will result in confirmation of the order and enforcement of the order and the alleged arrearages and precludes further contest of that order with respect to any matter that could have been asserted; and

(4) of the amount of any alleged arrearages.

(c) If the registering party asserts that two or more orders are in effect, a notice must also:

(1) identify the two or more orders and the order alleged by the registering party to be the controlling order and the consolidated arrears, if any;

(2) notify the nonregistering party of the right to a determination of which is the controlling order;

(3) state that the procedures provided in subsection (b) of this section apply to the determination of which is the controlling order; and

(4) state that failure to contest the validity or enforcement of the order alleged to be the controlling order in a timely manner may result in confirmation that the order is the controlling order.

(d) Upon registration of an income withholding order for enforcement, the support enforcement agency or the registering tribunal shall notify the obligor’s employer pursuant to Subtitle 1 of this title.