ICD-10 Code H70.20 – Unspecified Petrositis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H70.20 – Unspecified petrositis
What it is
H70.20 identifies petrositis when the petrous part of the temporal bone is inflamed, but the record does not specify the cause or laterality. Use this code when documentation is limited to “unspecified petrositis.”
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings may include ear pain, persistent otitis media, headache, and signs of adjacent cranial nerve irritation, but you should not assume these are present without support.
When to use this code
Use H70.20 when the provider documents petrositis without naming a more specific type or site detail. It also fits chart notes that confirm petrositis but do not identify the underlying infectious process or complication.
If the record later specifies another mastoid or temporal bone condition, code the documented diagnosis instead. When the wording is unclear, check documentation before assigning this code.
Do not use for
Do not use this code for general otitis media, mastoiditis, or other ear infections unless petrositis is explicitly documented. Also avoid it when the chart gives a more specific petrositis code.
Coding tip
Query the provider if petrositis is mentioned without enough detail to confirm whether an unspecified code is appropriate.