Md. Code, Courts and Judicial Proceedings § 6–103.1

A court may exercise personal jurisdiction over a nonresident defendant in any civil proceeding arising out of the marital relationship or involving a demand for child support, spousal support, or counsel fees if the plaintiff resides in this State at the time suit is filed and the nonresident defendant has been personally served with process in accordance with the Maryland Rules and:

(1) This State was the matrimonial domicile of the parties immediately before their separation; or

(2) The obligation to pay child support, spousal support, or counsel fees arose under the laws of this State or under an agreement executed by one of the parties in this State.