If you have Personal Injury Protection (PIP) coverage on your auto insurance policy, you should send your medical bills to your auto insurance and they will pay for them up to the limits of your PIP coverage, regardless of who was at fault for the accident.  If you do not have PIP coverage, and/or if your PIP coverage gets exhausted (used up), you should have your medical providers bill your medical insurance and contact a personal injury attorney about your options going forward.