ICD-10 Code H70.11 – Chronic mastoiditis, right ear (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H70.11 – Chronic mastoiditis, right ear
What it is
H70.11 identifies chronic inflammation or infection of the mastoid air cells in the right ear. Use it when the documentation specifically states chronic mastoiditis on the right side.
Clinical signs
Findings may include persistent ear drainage, ear pain, hearing loss, or tenderness behind the ear. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents chronic mastoiditis affecting the right mastoid or right ear. It is appropriate for ongoing or recurrent mastoid disease when the laterality is clearly stated. If the record does not specify the side, check documentation.
Do not use for
Do not use H70.11 for acute mastoiditis or for mastoid disease on the left side or both sides. If the note only mentions ear infection without mastoid involvement, this code is not appropriate.
Coding tip
Always verify laterality in the assessment or impression before assigning H70.11.