surgery with 2 surgeons

My doctor did a thyroidectomy including a substernal 60270

another doctor opened the sternum, my doctor did the surgery and the other doctor closed the sternum

we charged 60720-62
they charged 60270
medicare paid them and denied us..stating paid once in a pt's lifetime...

what should we have charged?

co-surgeons

Co-surgeons could be paid with supporting documentation to Medicare. Both surgeons must put modifier -62 on the same CPT code.