ICD-10 Code H70.203 – Unspecified petrositis, bilateral (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H70.203 – Unspecified petrositis, bilateral
What it is
This code identifies inflammation or infection involving both petrous portions of the temporal bones, when the record does not specify the cause or type. Use it when the documentation clearly states bilateral petrositis but remains otherwise nonspecific.
Clinical signs
Clinical features vary; refer to documentation. Petrositis may be associated with ear pain, headache, fever, or complications from adjacent ear infection, but you should code only what is documented.
When to use this code
Use H70.203 when the provider documents bilateral petrositis and does not identify a more specific form, such as infectious organism or related complication. It may also apply when imaging or specialist notes confirm bilateral involvement but the chart remains nonspecific. Check documentation if laterality or etiology is unclear.
Do not use for
Do not use this code for unilateral petrositis or for a more specific diagnosis that is documented elsewhere. If the record only mentions otitis media, mastoiditis, or another ear condition without petrositis, code the stated condition instead.
Coding tip
Confirm both laterality and the exact term “petrositis” in the provider note before assigning H70.203.