ICD-10 Code H33.123 – Parasitic cyst of retina, bilateral (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H33.123 – Parasitic cyst of retina, bilateral
What it is
This code identifies a parasitic cyst affecting the retina in both eyes. Use it when documentation clearly states bilateral retinal involvement from a parasitic cause.
Clinical signs
Clinical features vary; refer to documentation. Findings may include retinal lesion(s), visual disturbance, or ophthalmic exam evidence supporting a parasitic cyst in each eye.
When to use this code
Use H33.123 when the provider documents a parasitic cyst of the retina and specifies that both eyes are involved. It may appear in ophthalmology notes, imaging reports, or problem lists. If laterality is not stated, check documentation before coding.
Do not use for
Do not use this code for a retinal cyst without parasitic cause, or for disease limited to one eye. If the record only says “retinal lesion” or “cyst,” check documentation.
Coding tip
Confirm both the parasitic etiology and bilateral laterality in the provider note before assigning H33.123.