Question: My pain management physician performedan ulnar block to treat a finger fracture. What is the correct code for this block? Kansas Subscriber Answer: The coding for an isolated ulnar block is 64450 (Injection, anesthetic agent; other peripheral nerve or branch). If your physician provides the block for surgery, the anesthesia code for the surgical procedure should be used and base units and time billed as opposed to the flat fee of 64450. The ulnar nerve can be blocked at the wrist or elbow commonly, though it could be done anywhere during its course.