ICD-10 Code G12.0 – Infantile spinal muscular atrophy, type I [Werdnig-Hoffman] (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G12.0 – Infantile spinal muscular atrophy, type I [Werdnig-Hoffman]
What it is
G12.0 identifies infantile spinal muscular atrophy type I, also called Werdnig-Hoffman disease. It is a severe inherited motor neuron disorder causing profound muscle weakness beginning in infancy.
Clinical signs
Typical findings include marked hypotonia, poor head control, weak suck, and progressive difficulty breathing or swallowing. Clinical features vary; refer to documentation.
When to use this code
Use this code when the record specifically documents infantile spinal muscular atrophy type I or Werdnig-Hoffman disease. Code it for confirmed diagnoses in infants with classic proximal weakness and motor neuron involvement. Check documentation if the note only says spinal muscular atrophy without type.
Do not use for
Do not use G12.0 for other spinal muscular atrophy types, carrier status, or nonspecific muscle weakness. Do not assume the diagnosis from family history alone.
Coding tip
Verify the exact SMA type in the assessment or problem list before assigning G12.0.