ICD-10 Code G31.81 – Alpers Disease (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G31.81 – Alpers disease
What it is
G31.81 identifies Alpers disease, a rare progressive neurologic disorder. Use it for documentation of this specific mitochondrial encephalopathy when the diagnosis is established.
Clinical signs
Clinical features vary; refer to documentation. Typical references describe progressive neurologic decline, seizures, and liver involvement, often with developmental regression or loss of skills.
When to use this code
Use G31.81 when the record clearly states Alpers disease, Alpers-Huttenlocher syndrome, or another accepted synonym. Apply it for confirmed diagnoses in neurology, genetics, or inpatient problem lists. If the chart only notes unexplained seizures or encephalopathy, do not assign this code unless Alpers disease is documented.
Do not use for
Do not use this code for generic mitochondrial disease, epilepsy without Alpers disease, or nonspecific developmental delay. Check documentation if the provider has not confirmed the exact disorder.
Coding tip
Confirm the provider’s exact wording and code only when Alpers disease is explicitly documented.