ICD-10 Code H21.54 – Posterior synechiae (iris) (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H21.54 – Posterior synechiae (iris)
What it is
Posterior synechiae are adhesions between the iris and the lens. This code identifies iris sticking that can follow intraocular inflammation or other eye disease.
Clinical signs
Findings may include an irregular or poorly dilating pupil and visible iris adherence on exam. Clinical features vary; refer to documentation.
When to use this code
Use H21.54 when the provider documents posterior synechiae of the iris, with or without associated uveitis or prior inflammation. It is appropriate when the adhesion itself is the recorded diagnosis or a notable exam finding. Check documentation if the record only mentions a history of eye inflammation.
Do not use for
Do not use this code for other iris adhesions or unrelated pupillary abnormalities unless posterior synechiae are specifically documented. Do not assume the condition from nonspecific eye pain or redness alone.
Coding tip
Code the documented anatomic adhesion, and sequence any underlying eye condition when the record supports it.