ICD-10 Code H71.21 – Cholesteatoma of mastoid, right ear (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H71.21 – Cholesteatoma of mastoid, right ear
What it is
Use this code for a cholesteatoma located in the mastoid region of the right ear. It refers to an abnormal skin-lined growth that can erode nearby ear structures.
Clinical signs
Clinical features vary; refer to documentation. Commonly documented findings include chronic ear drainage, hearing loss, or evidence of a retraction pocket and destructive middle-ear disease on exam or imaging.
When to use this code
Assign H71.21 when the provider documents cholesteatoma specifically in the mastoid of the right ear. Use it for confirmed diagnoses in outpatient, inpatient, or surgical records when laterality and site are clear. If the note only says “cholesteatoma” without location, check documentation.
Do not use for
Do not use this code for cholesteatoma of the left ear or unspecified ear. Also avoid it when the record describes another ear disorder without confirmed mastoid cholesteatoma.
Coding tip
Verify both laterality and anatomic site in the operative note, imaging report, or assessment before coding.