ICD-10 Code H57.02 – Anisocoria (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H57.02 – Anisocoria
What it is
Anisocoria means the pupils are unequal in size. Use this code when documentation identifies unequal pupil diameter as the diagnosis or a recorded clinical finding.
Clinical signs
Findings usually include one pupil larger or smaller than the other, with the difference present at rest or noted on exam. Clinical features vary; refer to documentation.
When to use this code
Use H57.02 when the provider documents anisocoria as the condition being evaluated or observed. It may appear in eye, neurologic, or trauma-related notes when unequal pupils are specifically recorded. If the chart names an underlying cause, code that condition as well when instructed.
Do not use for
Do not use this code for normal, symmetric pupils or for vague eye complaints without documented anisocoria. Check documentation if the unequal pupils are better explained by another coded disorder.
Coding tip
Code the documented finding of anisocoria only when it is explicitly stated, and look for any underlying diagnosis that also needs reporting.