ICD-10 Code H57.03 – Miosis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H57.03 – Miosis
What it is
Miosis means abnormal constriction of the pupil. Use this code when documentation identifies pinpoint or persistently small pupils as the condition being addressed.
Clinical signs
Clinical features include visibly small pupils that may react poorly to light or remain constricted. Clinical features vary; refer to documentation.
When to use this code
Use H57.03 when the provider documents miosis as a diagnosis, finding, or reason for evaluation. It may appear in eye examinations, neurologic assessments, or toxicology-related notes when the constricted pupil is the coded finding. If the record names an underlying cause only, code that condition instead when instructed.
Do not use for
Do not use this code for normal pupil constriction or for symptoms not documented as miosis. Check documentation if the note describes anisocoria, mydriasis, or another specific pupil abnormality.
Coding tip
Confirm that the chart explicitly states miosis before assigning H57.03, and code the documented cause separately when appropriate.