Ask Dr. Z

You recommend code 47536 for cholecystostomy tube change in the IR reference instead of 47490-52. Code 47536 describes tube exchange in the bile duct, which is not the gallbladder. When the tip of the catheter resides in the gallbladder, why would you code it with 47536? Code 47490 describes insertion of "tube into the gallbladder to allow drainage". Since there is no code for the exchange of this tube, shouldn't it be coded with a -52 modifier for reduced service rather than coding for an exchange of a tube in a different location? Please explain your answer in the IR reference.