ICD-10 Code H21.263 – Iris atrophy (essential) (progressive), bilateral (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H21.263 – Iris atrophy (essential) (progressive), bilateral
What it is
H21.263 identifies progressive, essential atrophy of both irises. Use it when documentation describes bilateral thinning or loss of iris tissue without another clearer cause.
Clinical signs
Findings may include iris thinning, transillumination defects, and irregular pupil appearance. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents bilateral essential or progressive iris atrophy, or a diagnosis stated in equivalent terms. It may also fit follow-up visits when the condition remains active and is the reason for care. Check documentation if laterality or cause is unclear.
Do not use for
Do not use it for unilateral iris atrophy, traumatic iris defects, or atrophy clearly linked to another eye disorder. If the note names a different underlying cause, code that condition instead.
Coding tip
Verify both laterality and the exact wording “essential” or “progressive” before assigning H21.263.