Someone asked today for the Maryland case that prevents a parent from relocating to another state with the minor children before a custody order is entered.
Surprise! In Maryland, there is no case and no law against it. Some lawyers and some judges will disapprove of this tactic, especially in the middle of a school year, but it is not illegal.
Until there is a custody order, both parties have joint legal and physical custody of their children under the common law. That means either parent can take them anywhere.
It is then up to the parent left behind to go to court and try to get an order for their return.