The other parties’ insurance company is not obligated to pay your medical bills as they come due. The other driver is not obligated to pay anything to you until such time as a court of law rules that the other driver is responsible for your injuries, and a judgment is entered by the court awarding you damages. Until then, you have to pay your own medical bills. You can do this with your auto “med pay” insurance, your group or “regular” insurance, or Medicare/Medicaid if you have it.