If you have a medicare supplement, also known as a medigap policy, how is your doctor paid for the service provided? Medicare supplement insurance companies in most cases pay the doctor directly. This is the case if the doctor "participates" with Medicare. It would be advisable to have the doctor's office note on the Medicare claim form that you have a medicare supplement and want the doctor paid directly. You also want to be sure that the doctor has the right insurance company name and policy number. They may simply photocopy your insurance card.