ICD-10-CM Code G12.20

Motor neuron disease, unspecified

Version 2021 Billable Code

Valid for Submission

G12.20 is a billable code used to specify a medical diagnosis of motor neuron disease, unspecified. The code is valid for the fiscal year 2021 for the submission of HIPAA-covered transactions. The ICD-10-CM code G12.20 might also be used to specify conditions or terms like bilateral upper motor neurone lesion, corticospinal motor disease, frontal lobe degeneration with motor neurone disease, frontotemporal dementia, lower motor neuron disease, mills syndrome, etc

Short Description:Motor neuron disease, unspecified
Long Description:Motor neuron disease, unspecified

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code G12.20 are found in the index:


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Bilateral upper motor neurone lesion
  • Corticospinal motor disease
  • Frontal lobe degeneration with motor neurone disease
  • Frontotemporal dementia
  • Lower motor neuron disease
  • Mills syndrome
  • Motor neuron disease
  • Unilateral upper motor neurone lesion
  • Upper motor neurone lesion

Clinical Information

  • 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

Convert G12.20 to ICD-9

  • 335.29 - Motor neuron disease NEC (Approximate Flag)

Code Classification

  • Diseases of the nervous system (G00–G99)
    • Systemic atrophies primarily affecting the central nervous system (G10-G14)
      • Spinal muscular atrophy and related syndromes (G12)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Information for Patients

Amyotrophic Lateral Sclerosis

Also called: ALS, Lou Gehrig's disease

Amyotrophic lateral sclerosis (ALS) is a nervous system disease that attacks nerve cells called neurons in your brain and spinal cord. These neurons transmit messages from your brain and spinal cord to your voluntary muscles - the ones you can control, like in your arms and legs. At first, this causes mild muscle problems. Some people notice

  • Trouble walking or running
  • Trouble writing
  • Speech problems

Eventually, you lose your strength and cannot move. When muscles in your chest fail, you cannot breathe. A breathing machine can help, but most people with ALS die from respiratory failure.

The disease usually strikes between age 40 and 60. More men than women get it. No one knows what causes ALS. It can run in families, but usually it strikes at random. There is no cure. Medicines can relieve symptoms and, sometimes, prolong survival.

NIH: National Institute of Neurological Disorders and Stroke

  • Amyotrophic lateral sclerosis (Medical Encyclopedia)
  • Swallowing problems (Medical Encyclopedia)

[Learn More]

Neuromuscular Disorders

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

  • The nerves that control your muscles
  • Your muscles
  • Communication between your nerves and muscles

These disorders can cause your muscles to become weak and waste away. You may also have symptoms such as spasms, twitching, and pain.

Examples of neuromuscular disorders include

  • Amyotrophic lateral sclerosis
  • Muscular dystrophy
  • Myasthenia gravis
  • Spinal muscular atrophy

There can be different causes for these diseases. Many of them are genetic.This means they are inherited (run in families) or are caused by a new mutation in your genes. Some neuromuscular disorders are autoimmune diseases. Sometimes the cause is not known.

Many neuromuscular diseases have no cure. But treatments may improve symptoms, increase mobility, and lengthen life.

  • Apraxia (Medical Encyclopedia)
  • Hand or foot spasms (Medical Encyclopedia)
  • Muscle atrophy (Medical Encyclopedia)
  • Muscle function loss (Medical Encyclopedia)
  • Muscle twitching (Medical Encyclopedia)
  • Myotonia congenita (Medical Encyclopedia)
  • Spasticity (Medical Encyclopedia)

[Learn More]