ICD-10 Code H70.89 – Other mastoiditis and related conditions (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H70.89 – Other mastoiditis and related conditions
What it is
This code identifies mastoid inflammation or related mastoid conditions that do not fit a more specific ICD-10-CM category. Use it for documented mastoid disease when the record supports a nonspecific or other specified diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Commonly noted findings may include postauricular pain, swelling, redness, ear discharge, or tenderness over the mastoid area, but the chart must support the diagnosis.
When to use this code
Use H70.89 when the provider documents mastoiditis or a related mastoid condition and no more specific code applies. It is appropriate when the note clearly distinguishes this from acute, chronic, or other named mastoid disorders. Check documentation if the diagnosis is unclear.
Do not use for
Do not use this code for acute mastoiditis, chronic mastoiditis, or mastoiditis with another specified category when a more exact code is documented. Do not assign it for ear pain alone without confirmed mastoid involvement.
Coding tip
Query for the exact mastoid diagnosis and laterality details if the record only says “mastoiditis” or “mastoid disease.”