ICD-10 Code B02.21 – Postherpetic geniculate ganglionitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B02.21 – Postherpetic geniculate ganglionitis
What it is
This code identifies postherpetic inflammation of the geniculate ganglion, a nerve ganglion affected after herpes zoster. Use it when documentation specifies this post-zoster cranial nerve complication.
Clinical signs
Clinical features vary; refer to documentation. Typical references describe persistent facial nerve pain or neuropathic symptoms after shingles involving the geniculate ganglion.
When to use this code
Use B02.21 when the provider documents postherpetic geniculate ganglionitis, post-zoster ganglionitis, or a similar specific complication tied to the geniculate ganglion. Code it when the condition is clearly linked to prior herpes zoster and not described more generally.
Do not use for
Do not use this code for uncomplicated shingles, facial pain without a postherpetic diagnosis, or other cranial nerve disorders. Check documentation if the record only says herpes zoster or neuralgia.
Coding tip
Confirm that the note names the geniculate ganglion and a postherpetic cause before assigning B02.21.