ICD-10 Code G12.9 – Spinal muscular atrophy, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G12.9 – Spinal muscular atrophy, unspecified
What it is
G12.9 identifies spinal muscular atrophy when the record confirms SMA but does not specify a type or subtype. It refers to a motor neuron disorder that causes progressive muscle weakness and wasting.
Clinical signs
Clinical features vary; refer to documentation. Common findings include proximal weakness, reduced muscle tone, loss of reflexes, and difficulty with motor milestones or walking. Respiratory or bulbar involvement may be documented in more advanced cases.
When to use this code
Use G12.9 when the provider documents spinal muscular atrophy without naming a specific type, such as SMA type 1, 2, or 3. It also fits when the chart confirms SMA but the subtype is not available in the note or problem list.
If the documentation later identifies a specific SMA form, code the more specific diagnosis instead. Check documentation when the record only says “muscular weakness” or another nonspecific neuromuscular disorder.
Do not use for
Do not use G12.9 for generalized muscle weakness, muscular dystrophy, or other neuromuscular conditions without documented spinal muscular atrophy. Do not assign it when a more specific SMA code is clearly documented.
Coding tip
Code the most specific SMA type available; use G12.9 only when the provider leaves the subtype unspecified.