If you are involved in an accident and you have Medicare you need to read over this. Medicare would NOT be the primary source of payment. It would be the other party who pays. You would have to pay Medicare back. I needed to look this up for work and I noticed it was explained very simply here so if you have Medicare it may be worth reading over so you do not end up with a ton of Leins on you and owing a bunch of money to Medicare!
http://www.adminastar.com/Providers/MSP/AttorneyInformation/files/AttorneyInfoweb305.pdf