Question: My ophthalmologist performed an aqueous shunt but added an additional step. Before closing the conjunctiva, she sutured a donor pericardial graft over the tube before closing. Is there an appropriate way to code the extra step taken because it is not listed in the shunt's code description? Virginia Subscriber Answer: For the aqueous shunt insertion, you should report 66180 (Aqueous shunt to extraocular reservoir [e.g., Molteno, Schocket, Denver-Krupin]). You can, in fact, report an additional code for the graft. Use 67255 (Scleral reinforcement [separate procedure]; with graft). Because the ophthalmologist doesn't have to perform 67255 on every patient who gets a shunt, be sure the documentation includes information about the scleral thinning or other reason for the reinforcement procedure to support medical necessity for the additional procedure. Note: You may need to append modifier 51 (Multiple procedures) to 67255, depending on your carrier, because your physician performed more than one procedure during the same operative session. Medicare doesn't require you to use modifier 51 on a Medicare claim because the carrier will automatically add it, but you'll likely need the modifier for private payers. Link the appropriate glaucoma diagnosis to 66180 for the shunt insertion, and link 379.04 (Scleromalacia perforans) to 67255 for the graft.