Question: Which code should I report for a ganglion impar block? Mississippi Subscriber Answer: Reporting a ganglion impar block is one of the gray areas of coding that doesn't seem to have a consensus of opinion on the best code. Some coders recommend 64530 (Injection, anesthetic agent; celiac plexus, with or without radiologic monitoring). Others recommend using the 20-unit code 64640 (Destruction by neurolytic agent; other peripheral nerve or branch) if it is a neurolytic injection. Your last option is to report CPT 64999 (Unlisted procedure, nervous system) at 12 RVUs. Many carriers, such as Medicare carrier First Coast Options in Florida, require 64999 for ganglion impar blocks along with documentation of medical necessity.