ICD-10 Code H91.21 – Sudden idiopathic hearing loss, right ear (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H91.21 – Sudden idiopathic hearing loss, right ear
What it is
This code identifies a sudden, unexplained loss of hearing in the right ear. Use it when the record documents idiopathic onset and the right side is specifically involved.
Clinical signs
Typical findings include rapid hearing decrease, often over hours to days, with no clear cause documented. Clinical features vary; refer to documentation for laterality, severity, and associated symptoms.
When to use this code
Use H91.21 when the clinician diagnoses sudden idiopathic hearing loss affecting only the right ear. The chart should support sudden onset and exclude a known cause such as trauma, infection, or medication effect. If documentation is incomplete, check documentation before assigning the code.
Do not use for
Do not use this code for left ear or bilateral sudden hearing loss, or when the hearing loss has a documented cause. If the record does not specify idiopathic and right-sided involvement, check documentation.
Coding tip
Confirm both sudden onset and right-ear laterality in the provider note before coding.