ICD-10 Code H21.26 – Iris atrophy (essential) (progressive) (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H21.26 – Iris atrophy (essential) (progressive)
What it is
H21.26 identifies progressive, essential atrophy of the iris, meaning thinning or loss of iris tissue not explained by another listed eye disorder. Use it when documentation specifically names this condition.
Clinical signs
Typical findings may include iris thinning, transillumination defects, and abnormal pupil appearance. Clinical features vary; refer to documentation.
When to use this code
Use H21.26 when the provider documents essential or progressive iris atrophy as the diagnosis. It fits ophthalmology notes describing structural iris loss without a more specific underlying cause. If the record only says “iris abnormality” or is unclear, check documentation before assigning the code.
Do not use for
Do not use this code for traumatic iris damage, congenital iris defects, or other named iris disorders. If the chart identifies a different cause of iris thinning, code that condition instead.
Coding tip
Confirm that “essential” or “progressive” iris atrophy is explicitly documented before coding H21.26.