ICD-10 Code G90.9 – Disorder of the autonomic nervous system, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G90.9 – Disorder of the autonomic nervous system, unspecified
What it is
G90.9 is used for an autonomic nervous system disorder when the documentation does not specify the exact type. It covers problems involving involuntary body functions such as heart rate, blood pressure, digestion, or sweating.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings may include dizziness, fainting, abnormal sweating, gastrointestinal motility issues, or blood pressure instability.
When to use this code
Use G90.9 when the provider documents an autonomic nervous system disorder but does not identify a more specific diagnosis. It may also fit when records describe autonomic dysfunction, dysautonomia, or similar terms without further detail. If the chart supports a specific autonomic disorder, code that condition instead.
Do not use for
Do not use G90.9 when the documentation names a specific autonomic disorder, such as a clearly identified neuropathic or degenerative condition. Check documentation if the cause is another neurologic, endocrine, or systemic disorder.
Coding tip
Query for specificity whenever the record says only “autonomic dysfunction” or “dysautonomia.”