Md. Code, Family Law § 10–138

(a) Upon request of the obligor, the court shall immediately authorize service of an earnings withholding order.

(b) Notwithstanding any other provision of this Part III, a court may at any time issue an earnings withholding order, in a contempt or other proceeding, if:

(1) the recipient or the support enforcement agency has filed a petition that includes a request for an earnings withholding order; and

(2) the obligor is in arrears in support payments of more than 30 days.

(c) A hearing shall be held if the obligor appears and contests the issuance of the order.

(d) The amount of the wage withholding order entered under this subsection:

(1) shall be enough to pay the support as originally entered by the court; and

(2) may include a part of the arrearage.