Question: My anesthesiologist performed a sciatic nerve block for a patient with postoperative pain on the same day he provided general anesthesia for that patients knee surgery. How should I code this?Mississippi Subscriber Answer: Use modifier 59 (Distinct procedural service) when you need to show that your physician performed two distinct services on the same day. When your physician places a sciatic nerve block for postoperative pain management (for example, 64445, Injection,anesthetic agent; sciatic nerve, single), and on the same day provided general anesthesia for knee surgery (01400,Anesthesia for open or surgical arthroscopic procedures on knee joint; not otherwise specified), your final codes are 64445-59 for the block, along with 01400 for the anesthesia.