Question: Our surgeon performed ERCP to remove three stones from the bile duct. The surgeon passed a guidewire and catheter into the duct and passed a basket over the guidewire to trap and remove the stones. How should we code the case? Does the number of stones removed impact the coding? Kentucky Subscriber Answer: The appropriate coding for the scenario you describe is a single unit of 43264 (Endoscopic retrograde cholangiopancreatography (ERCP); with removal of calculi/debris from biliary/pancreatic duct(s)). This is the correct coding for the method you described or for any other method, such as passing a balloon over the guidewire to dredge out the stones. The method(s) or number of stones involved in a single surgical session doesn’t impact the code selection or the number of units. Caution: You should not report 43264 in addition to either of the following codes for the same surgical session: