ICD-10 Code H70.091 – Acute mastoiditis with other complications, right ear (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H70.091 – Acute mastoiditis with other complications, right ear
What it is
This code identifies an acute infection of the mastoid air cells in the right ear with complications not named elsewhere in the code set. Use it when documentation specifies mastoiditis, right side, and another complication is present.
Clinical signs
Typical findings include ear pain, swelling or tenderness behind the ear, and signs of acute ear infection. Clinical features vary; refer to documentation for the exact complication and right-sided involvement.
When to use this code
Use H70.091 when the provider documents acute mastoiditis of the right ear and notes a complication that is not captured by a more specific code. It also fits when the record clearly supports acute mastoid involvement plus an additional complication, but does not name another exact subtype. Check documentation if laterality or complication details are unclear.
Do not use for
Do not use this code for mastoiditis without complications, left ear, bilateral disease, or chronic mastoiditis. Do not assign it when the chart does not confirm the right ear or the complication.
Coding tip
Verify laterality and the documented complication before coding, because a more specific mastoiditis code may be available.