ICD-10 Code H91.20 – Sudden idiopathic hearing loss, unspecified ear (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H91.20 – Sudden idiopathic hearing loss, unspecified ear
What it is
H91.20 identifies sudden, unexplained hearing loss affecting an ear when the affected side is not documented. Use it for an idiopathic presentation, meaning no clear cause is recorded.
Clinical signs
Patients usually report rapid hearing loss, often noticed over hours to days. Clinical features vary; refer to documentation for laterality, associated tinnitus, vertigo, or exam findings.
When to use this code
Use this code when the record states sudden idiopathic hearing loss but does not specify right or left ear. It also fits when the clinician documents sudden sensorineural loss without a stated cause and the affected ear remains unspecified. Check documentation if another diagnosis explains the hearing change.
Do not use for
Do not use it when the chart identifies the right or left ear, because a more specific code may apply. Do not assign it if the hearing loss has a known cause, such as trauma, infection, or medication exposure.
Coding tip
Confirm both sudden onset and unspecified ear in the note before assigning H91.20.