ICD-10 Code H21.323 – Implantation cysts of iris, ciliary body or anterior chamber, bilateral (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H21.323 – Implantation cysts of iris, ciliary body or anterior chamber, bilateral
What it is
This code identifies implantation cysts affecting both eyes’ iris, ciliary body, or anterior chamber. These are epithelial-lined cysts that form after tissue implantation, usually following trauma or surgery.
Clinical signs
Findings may include a visible cystic lesion on eye examination, anterior segment distortion, or reduced visual clarity. Clinical features vary; refer to documentation and ophthalmology assessment.
When to use this code
Use H21.323 when the provider documents bilateral implantation cysts involving the iris, ciliary body, or anterior chamber. Code it when the record clearly states the location and that both eyes are affected. Check documentation if the laterality or structure involved is unclear.
Do not use for
Do not use this code for unilateral cysts or for other anterior segment cysts without implantation etiology. Do not assign it when the diagnosis is only suspected or not documented.
Coding tip
Confirm both laterality and the exact anatomic site before coding; H21.323 is specific to bilateral implantation cysts.