ICD-10 Code H70.8 – Other mastoiditis and related conditions (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H70.8 – Other mastoiditis and related conditions
What it is
This code identifies mastoid inflammation or related mastoid conditions that do not fit a more specific H70 category. Use it when the record supports mastoid involvement, but the exact subtype is not documented.
Clinical signs
Findings may include mastoid tenderness, swelling, ear pain, fever, or otitis media history. Clinical features vary; refer to documentation and imaging or specialist assessment when available.
When to use this code
Use H70.8 when the clinician documents mastoiditis or a related mastoid condition and does not name another specific code. It is appropriate for nonspecific or residual mastoid disease when the chart supports the diagnosis. If the note identifies a more specific mastoid disorder, code that instead.
Do not use for
Do not use this code for routine ear infections without mastoid involvement. Also avoid it when documentation supports a more specific mastoiditis code or another clearly defined ear diagnosis.
Coding tip
Code from the provider’s exact wording; if “related condition” is vague, check documentation before assigning H70.8.