Legal Question in Family Law in Maryland

Unfortunately, unless your ex cooperates by getting the required insurance in compliance with the agreement or order imposing this requirement on her, you will have to go to court. If this requirement is mandated by a court order or judgment of divorce, you would file a "show cause" petition asking the court to hold her in contempt and pay your legal costs. She would probably be given a short deadline to demonstrate that she has coverage in place or risk further sanctions. Obviously this could involve a lot more than $300 going forward. As for the pending bill, perhaps if you lay out these possibilities for her, she will pony up. If not, and you have the requisite documentation of her obligation to provide the coverage, you could always pay the bill and take her to small claims court, although whether this is worth your time, even doing it yourself, is questionable.