2026 ICD-10-CM Diagnosis Code G12.23Primary lateral sclerosis

ICD-10-CM Codes›G00–G99›G10-G14›G12

ICD-10-CM G12.23
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G12.23 is a billable ICD-10-CM diagnosis code for primary lateral sclerosis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as juvenile primary lateral sclerosis. 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
G12.23
Billable Status
Yes — Valid for Submission
Code Describes
Primary lateral sclerosis
Short Description
Primary lateral sclerosis
Same as the full description in the CMS dataset.
Parent Code
G12.2
Motor neuron disease

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG10-G14Systemic atrophies primarily affecting the central nervous system
CategoryG12Spinal muscular atrophy and related syndromes
This CodeG12.23Primary lateral sclerosis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Juvenile primary lateral sclerosis
  • Primary lateral sclerosis
  • Upper motor neuron 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.

    • Paralysis, paralytic(complete) (incomplete)
      • lateral
    • Sclerosis, sclerotic
      • lateral (amyotrophic) (descending) (spinal)
        • primary
    • Sclerosis, sclerotic
      • primary, lateral
    • Sclerosis, sclerotic
      • spinal (cord) (progressive)
        • lateral (amyotrophic)
          • progressive

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

Clinical InformationClinical

  • Amyotrophic Lateral Sclerosis

    a degenerative disorder affecting upper motor neurons in the brain and lower motor neurons in the brain stem and spinal cord. disease onset is usually after the age of 50 and the process is usually fatal within 3 to 6 years. clinical manifestations include progressive weakness, atrophy, fasciculation, hyperreflexia, dysarthria, dysphagia, and eventual paralysis of respiratory function. pathologic features include the replacement of motor neurons with fibrous astrocytes and atrophy of anterior spinal nerve roots and corticospinal tracts. (from adams et al., principles of neurology, 6th ed, pp1089-94)

  • Motor Neuron Disease

    diseases characterized by a selective degeneration of the motor neurons of the spinal cord, brainstem, or motor cortex. clinical subtypes are distinguished by the major site of degeneration. in amyotrophic lateral sclerosis there is involvement of upper, lower, and brainstem motor neurons. in progressive muscular atrophy and related syndromes (see muscular atrophy, spinal) the motor neurons in the spinal cord are primarily affected. with progressive bulbar palsy (bulbar palsy, progressive), the initial degeneration occurs in the brainstem. in primary lateral sclerosis, the cortical neurons are affected in isolation. (adams et al., principles of neurology, 6th ed, p1089)

Patient EducationClinical

Neuromuscular Disorders

Neuromuscular disorders affect your neuromuscular system. They can cause problems with:

Read the full article at MedlinePlus

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

Convert G12.23 to ICD-9-CMHistory

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

ICD-9-CM
335.24 Prim lateral sclerosis
Exact Match The mapping is direct, with no qualifiers.

Code History & ChangesHistory

Replacement G12.23 replaces the following previously assigned code(s):

  • G12.29 - Other motor neuron disease
FY 2018AddedAdded to the ICD-10-CM code setEffective October 1, 2017.
FY 2019–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About G12.23Overview

Is G12.23 (Motor neuron disease) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report primary lateral sclerosis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of G12.23?

Under the General Equivalence Mappings, primary lateral sclerosis converts to ICD-9-CM 335.24 (prim lateral sclerosis). 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.