When billing a bubble study done in a physicians office should a 90774 be billed in addition to A4216 for both Medicare and commercial payors? Cardiology coding alert states to bill 90774 and A4216 for commercial payors but only shows A4216 for the Medcare. I didn't know if there was a reason why they only show the A4216 for the Medicare... Looks like you would still need to bill both codes no matter what the insurance carrier is. 90774 is a Medicare payable code I just wanted to know if anyone had any insight on what the difference would be. Any help would be appreciated.