ICD-10 Code H21.561 – Pupillary abnormality, right eye (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H21.561 – Pupillary abnormality, right eye
What it is
This code identifies an abnormal pupil finding limited to the right eye. It is used when the pupil’s size, shape, or reaction is not normal and the documentation specifies the right side.
Clinical signs
Findings may include an irregularly shaped pupil, unequal pupil size, or abnormal response to light in the right eye. Clinical features vary; refer to documentation.
When to use this code
Use H21.561 when the provider documents a pupillary abnormality in the right eye without assigning a more specific diagnosis. It is appropriate for office, emergency, or ophthalmology notes that clearly identify the right eye. Check documentation if the abnormality is described only as bilateral or unspecified.
Do not use for
Do not use this code for left-eye or bilateral pupillary abnormalities, or when the chart does not specify the right eye. If the abnormal pupil is part of a broader condition, code the documented underlying diagnosis instead.
Coding tip
Confirm laterality and whether the note describes a standalone pupillary abnormality before assigning H21.561.