ICD-10 Code G04.82 – Acute flaccid myelitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G04.82 – Acute flaccid myelitis
What it is
G04.82 identifies acute flaccid myelitis, a rare neurologic condition that affects the spinal cord and causes sudden limb weakness. It is used when the provider documents this specific diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include abrupt weakness, decreased muscle tone, and reduced reflexes, often with asymmetric arm or leg involvement.
When to use this code
Use G04.82 when the record clearly states acute flaccid myelitis, or when the clinician documents AFM as the confirmed diagnosis. Apply it for encounters focused on evaluation, management, or follow-up of this condition.
Do not infer the code from nonspecific weakness alone. If the chart only notes myelitis, paralysis, or neurologic symptoms without AFM, check documentation for the exact diagnosis.
Do not use for
Do not use this code for general muscle weakness, Guillain-Barré syndrome, or other myelitis types unless acute flaccid myelitis is specifically documented.
Coding tip
Code G04.82 only when the provider names acute flaccid myelitis; otherwise, query or check documentation for a more specific diagnosis.