2026 ICD-10-CM Diagnosis Code G12.0Infantile spinal muscular atrophy, type I [Werdnig-Hoffman]

ICD-10-CM Codes›G00–G99›G10-G14›G12

ICD-10-CM G12.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G12.0 is a billable ICD-10-CM diagnosis code for infantile spinal muscular atrophy, type I [Werdnig-Hoffman]. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as anterior horn cell disease. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other nervous system disorders (often hereditary or degenerative).

Code Identity

ICD-10-CM Code
G12.0
Billable Status
Yes — Valid for Submission
Code Describes
Infantile spinal muscular atrophy, type I [Werdnig-Hoffman]
Short Description
Infantile spinal muscular atrophy, type I [Werdnig-Hoffman]
Same as the full description in the CMS dataset.
Parent Code
G12
Spinal muscular atrophy and related syndromes

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG10-G14Systemic atrophies primarily affecting the central nervous system
CategoryG12Spinal muscular atrophy and related syndromes
This CodeG12.0Infantile spinal muscular atrophy, type I [Werdnig-Hoffman]

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Anterior horn cell disease
  • Spinal muscular atrophy
  • Werdnig-Hoffmann disease

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Atrophy, atrophic(of)
      • muscle, muscular (diffuse) (general) (idiopathic) (primary)
        • infantile spinal
    • Atrophy, atrophic(of)
      • muscle, muscular (diffuse) (general) (idiopathic) (primary)
        • progressive (bulbar)
          • infantile (spinal)
    • Atrophy, atrophic(of)
      • muscle, muscular (diffuse) (general) (idiopathic) (primary)
        • progressive (bulbar)
          • spinal
            • infantile
    • Atrophy, atrophic(of)
      • muscle, muscular (diffuse) (general) (idiopathic) (primary)
        • spinal
          • infantile, type I (Werdnig-Hoffmann)
    • Atrophy, atrophic(of)
      • Werdnig-Hoffmann
    • Disease, diseased
      • Werdnig-Hoffmann
    • Syndrome
      • Hoffmann-Werdnig
    • Syndrome
      • Werdnig-Hoffman
    • Werdnig-Hoffmann syndrome(muscular atrophy)

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS006
Other nervous system disorders (often hereditary or degenerative)
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Spinal Muscular Atrophy

Spinal muscular atrophy (SMA) is a group of genetic diseases that damages and kills motor neurons. Motor neurons are a type of nerve cell in the spinal cord and lower part of the brain. They control movement in your arms, legs, face, chest, throat, and tongue.

The full article covers:

  • What is spinal muscular atrophy (SMA)?
  • What are the types of spinal muscular atrophy (SMA) and what are their symptoms?
  • What causes spinal muscular atrophy (SMA)?
  • How is spinal muscular atrophy (SMA) diagnosed?
  • What are the treatments for spinal muscular atrophy (SMA)?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert G12.0 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
335.0 Werdnig-hoffmann disease
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About G12.0Overview

Is G12.0 (Spinal muscular atrophy and related syndromes) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report infantile spinal muscular atrophy, type I [Werdnig-Hoffman] on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of G12.0?

Under the General Equivalence Mappings, infantile spinal muscular atrophy, type I [Werdnig-Hoffman] converts to ICD-9-CM 335.0 (werdnig-hoffmann disease). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.