ICD-10 Code H21.349 – Primary cyst of pars plana, unspecified eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H21.349 – Primary cyst of pars plana, unspecified eye
What it is
This code identifies a primary cyst arising from the pars plana, the peripheral part of the ciliary body, in an unspecified eye. It is used when documentation confirms the lesion but does not name the right or left eye.
Clinical signs
Clinical features vary; refer to documentation. The cyst is often found on eye examination or imaging as a cystic lesion in the pars plana, sometimes with no symptoms and no vision change.
When to use this code
Use H21.349 when the provider documents a primary pars plana cyst and does not specify which eye is affected. It also fits when the record describes a cystic lesion of the pars plana without another more specific diagnosis. Check documentation if the note suggests a secondary, traumatic, or inflammatory cause.
Do not use for
Do not use this code for cysts clearly documented in the right or left eye, or for non-pars plana ocular cysts. Do not assign it when the finding is secondary to another condition unless the provider states a primary cyst.
Coding tip
If laterality is missing, code the unspecified-eye option only after confirming the chart does not identify the affected eye.