Neurology & Pain Management Coding Alert

Question: How do I code for anesthetic injections into the greater occipital nerve versus the trigeminal nerve? I know that there are a lot of anesthetic injection codes depending on anatomy, but I think I’ve got my coding choice narrowed to these two areas.

Idaho Subscriber

Answer: Coding for these injections is easy enough — once you decide whether the physician injected the occipital or trigeminal nerve. For trigeminal nerve injections, report 64400 (Injection, anesthetic agent; trigeminal nerve, any division or branch). For greater occipital nerve injections, choose 64405 (Injection, anesthetic agent; greater occipital nerve).

64400 specifics: The trigeminal nerve delivers most of the sensory innervation to the face, and has three major branches: 

• Ophthalmic nerve, also known as V1 division. This nerve delivers sensory innervation to the forehead/eye area of the head.
• Maxillary nerve, also known as V2 division. This nerve delivery sensory innervation to the area around the upper jaw—from just below the eye to the upper lip. 
• Mandibular nerve, also known as V3 division. This nerve is responsible for sensory and motor innervation to the lower jaw area.

When coding for anesthetic injections, 64400 might be your choice if you see any of the above information in the encounter notes. Physicians might also perform trigeminal nerve injections for patients with cluster, migraine, or tension headaches; atypical facial pain; or trigeminal neuralgia. (This is not a list of 64400-eligible conditions, however. Check with your individual payer on medically necessary diagnoses for 64400.)

64405 specifics: The greater occipital nerve provides a good deal of sensory innervation to the head, especially toward the back. You might see “GON” used as an abbreviation for greater occipital nerve in the encounter notes. Patients suffering from neck pain, certain types of headaches and occipital neuralgia might be candidates for a greater occipital nerve block. (This is not a list of 64405-eligible conditions, however. Check with your individual payer on medically necessary diagnoses for 64405.)

The physician might also note “occipital headache” in the notes, but that is not enough information to make an informed ICD-10 choice. If your physician notes the patient’s condition as “occipital headache,” be sure to ask him for more clarification before choosing a diagnosis code.