We have a new gastroenterologist starting next week who needs to perform a certian number of Endoscopies under the supervision of one of our "seasoned" MD's. This is the first actual "brand new" Dr we've hired so I don't have any experience with this scenario. I have read that the modifier GC is only used for Medicare and Tricare and most of the time is not used at all, even for them. Does this mean that we would simply bill under the supervising MD and just make sure both MD's sign the report for documentation purposes? Or must we indicate in some other way on the claim forms that the service was performed by a new MD under a supervising, such as typing a note in Box 19? I want to be sure we cover all bases for Medicare as well as our commercial and private insurance companies and would appreciate any advice.