You could sue the patient, if he or she is late on ensuring payment is rendered, and, as you are filing the lawsuit, copy him on the papers.If you provided treatment to him, you are legally entitled to be paid for it by the patient--even if he did not have, is not eligible for, or does not cooperate with his insurer, he has to pay. Insurance merely provides a source of funds and mechanism for payment. Therefore, once the patient is late (has not paid or arranged for payment by when an invoice is due), you could take legal action. If you sue the patient and also copy him on the paperwork, that may make him realize his potential liability and that he needs to submit his paperwork.Alternatively, if you don't want to sue at this point--or there are no invoices currently in default (i.e. the patient still has time to pay), have a lawyer send him a letter, on lawfirm stationary, letting him know how much is owed and that if payment does not come from the insurer, you will  proceed against him. Again, that may motivate him to act.Whatever you're going to do, see if it can't be done today or tomorrow, while he still has time to get his paperwork in.