ICD-10 Code H55.0 – Nystagmus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H55.0 – Nystagmus
What it is
Nystagmus is an involuntary, repetitive eye movement. It may be horizontal, vertical, or rotary and can affect one or both eyes.
Clinical signs
Typical findings include rhythmic oscillation of the eyes, often with a patient report of blurred vision or dizziness. Clinical features vary; refer to documentation.
When to use this code
Use H55.0 when the provider documents nystagmus as the diagnosed condition, whether congenital or acquired, and no more specific code is recorded. Apply it when the note clearly identifies involuntary eye movement as the reason for evaluation or follow-up.
If the chart names a specific underlying disorder, code that condition first when directed by documentation and coding rules. Check documentation for laterality, type, or associated neurologic or vestibular findings.
Do not use for
Do not use this code for normal eye movements, transient eye drift, or unspecified visual complaints without documented nystagmus. Do not assign it when the record only mentions dizziness or vertigo without confirmation.
Coding tip
Confirm the provider actually documented nystagmus and capture any stated cause or associated condition before coding H55.0.