Unpaid HFD Ambulance bill

Does anyone know the risk of not paying a City of Houston Fire Department bill on time? I’m currently fighting with the insurance company so that they pay it, but the bill has been due for several months. I’ve been in contact with their billing department, as the claim takes forever. But if it goes unpaid for a long time, does anyone know what happens? Does it go to collections? Do they put a lien on my property?