ICD-10 Code G90.1 – Familial dysautonomia [Riley-Day] (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G90.1 – Familial dysautonomia [Riley-Day]
What it is
G90.1 identifies familial dysautonomia, a rare inherited disorder that affects the autonomic and sensory nervous systems. It is used when documentation specifically names Riley-Day syndrome or familial dysautonomia.
Clinical signs
Typical findings include abnormal autonomic function, reduced pain and temperature sensation, and recurrent episodes of blood pressure or breathing instability. Clinical features vary; refer to documentation.
When to use this code
Use G90.1 when the provider documents familial dysautonomia, Riley-Day syndrome, or a confirmed diagnosis of the same condition. Code the condition as documented, even if the note emphasizes autonomic dysfunction or hereditary sensory neuropathy. Check documentation if the record is unclear.
Do not use for
Do not use this code for nonspecific autonomic neuropathy or autonomic symptoms without a documented diagnosis of familial dysautonomia. Do not assign it when the chart only says “rule out” or “possible” without confirmation.
Coding tip
Verify that the diagnosis is explicitly stated, because autonomic symptoms alone do not support G90.1.