Question: Our provider administered a block near the skull base to treat occipital nerve pain, as well as an anesthetic injection beforehand. Which codes should we report for this service? Kansas Subscriber Answer: The answer depends on the occipital nerve that the provider addressed with the block. Typically, you'll report 64405 (Injection, anesthetic agent; greater occipital nerve) for an occipital nerve block, if the surgeon addressed the greater occipital nerve (GON), which originates from the C2 spinal nerve and provides sensory innervation to the posterior area of the scalp extending to the top of the head. Physicians typically inject the GON just above the base of the skull to treat occipital or cervicogenic headaches or neck pain. If the physician instead diagnosed lesser occipital nerve (LON) involvement, you should report 64450 (Injection, anesthetic agent; other peripheral nerve or branch). However, CPT® does not assign a specific code for LON block procedure, and therefore, 64450 doesn't specifically refer to a block. In cases when the doctor performs a block for the third occipital nerve (TON), you should report code 64490 (Injection[s], diagnostic or therapeutic agent, paravertebral facet [zygapophyseal] joint [or nerves innervating that joint] with image guidance [fluoroscopy or CT], cervical or thoracic; single level). You should not separately report the local anesthesia. Your clinician will administer local anesthesia into the overlying skin prior to administering the block. This helps to reduce the needle-track pain and ensures the patient is seated comfortably during the procedure.