92928 is a standard stent using a balloon to open the vessel. 92930 is for complex cases with hard, calcified plaque that a balloon can't move. In those cases, he must use a "drill" (atherectomy) to shave plaque before the stent fits. If he uses a Rotablator or Diamondback, 92930 is the right code. Using 92928 when he does an atherectomy means you’re missing the extra skill and time he put in