ICD-10 Code G90.3 – Multi-system degeneration of the autonomic nervous system (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G90.3 – Multi-system degeneration of the autonomic nervous system
What it is
G90.3 identifies multi-system degeneration of the autonomic nervous system, a disorder affecting involuntary body functions such as blood pressure, heart rate, and bladder control. It reflects a progressive autonomic failure syndrome.
Clinical signs
Clinical features commonly include orthostatic hypotension, urinary dysfunction, constipation, and abnormal sweating. Neurologic findings may vary; refer to documentation for the specific manifestations recorded.
When to use this code
Use G90.3 when the provider documents multi-system degeneration of the autonomic nervous system or a clearly equivalent diagnosis. Code it when the record supports autonomic failure as the primary condition, not merely a symptom list.
If the note describes a broader neurodegenerative disorder without naming this condition, check documentation before assigning the code. You should not infer G90.3 from nonspecific dizziness or fainting alone.
Do not use for
Do not use this code for isolated autonomic symptoms, such as simple syncope or dehydration-related low blood pressure. It is also not appropriate when the diagnosis is uncertain; check documentation.
Coding tip
Look for explicit provider wording of autonomic degeneration or autonomic failure before coding G90.3.