When you are injured in an accident in Missouri, it can be difficult to figure out where to have your medical bills sent. If you are on Medicare, it can be even more difficult, because Medicare is not supposed to pay for anything that is the responsibility of another carrier.  However, an automobile liability insurance carrier for the at-fault driver is not going to pay your hospital bill for you, and they won't give you any money at all to pay that bill until you are ready to settle your case.  That could take months--even years.  Most hospitals are not willing to wait long periods of time to get paid, and you should not have your credit ruined as a result of an unpaid hospital bill.  In this circumstance, Medicare will make a "conditional payment"  on that hospital bill if the auto insurer will not pay promptly.  A conditional payment is just that--it is a payment conditioned on the fact that Medicare be repaid for the payment at the time your case is resolved . For instance, if Medicare paid $5000 on your hospital bill, they will have a right to be repaid that $5000 when your case resolves.  So if you are hospitalized after an accident, you should still give the hospital your Medicare card so that they can bill Medicare if your case doesn't settle quickly.