ICD-10 Code H55.09 – Other forms of nystagmus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H55.09 – Other forms of nystagmus
What it is
H55.09 identifies nystagmus that does not fit a more specific ICD-10 category. It refers to involuntary, rhythmic eye movements documented as another form of nystagmus.
Clinical signs
Clinical features vary; refer to documentation. Typical records describe involuntary oscillation of the eyes, which may be horizontal, vertical, or rotary, and may be noted on exam or specialist evaluation.
When to use this code
Use this code when the provider documents nystagmus but does not specify a more precise type covered by another code. It is appropriate when the record clearly states “other forms” or the details are insufficient for a more specific classification.
Do not use for
Do not use H55.09 when the chart supports a more specific nystagmus code, such as one tied to a known pattern or cause. Check documentation if the diagnosis is actually dizziness, abnormal eye movement, or another neurologic finding.
Coding tip
Code the most specific nystagmus type documented, and default to H55.09 only when the record supports nystagmus but not a more detailed subtype.