2020 ICD-10-CM Diagnosis Code G12.21

Amyotrophic lateral sclerosis

    2016 2017 2018 2019 2020 Billable/Specific Code Adult Dx (15-124 years)
  • G12.21 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2020 edition of ICD-10-CM G12.21 became effective on October 1, 2019.
  • This is the American ICD-10-CM version of G12.21 - other international versions of ICD-10 G12.21 may differ.
ICD-10-CM Coding Rules
  • G12.21 is applicable to adult patients aged 15 - 124 years inclusive.
The following code(s) above G12.21 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to G12.21:
  • G00-G99
    2020 ICD-10-CM Range G00-G99

    Diseases of the nervous system

    Type 2 Excludes
    • certain conditions originating in the perinatal period (P04-P96)
    • certain infectious and parasitic diseases (A00-B99)
    • complications of pregnancy, childbirth and the puerperium (O00-O9A)
    • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
    • endocrine, nutritional and metabolic diseases (E00-E88)
    • injury, poisoning and certain other consequences of external causes (S00-T88)
    • neoplasms (C00-D49)
    • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
    Diseases of the nervous system
Approximate Synonyms
  • Progressive muscular atrophy
  • Restrictive lung disease due to amyotrophic lateral sclerosis
  • Restrictive lung mechanics due to als
Clinical Information
  • 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)
  • A rare, milder form of amyotrophic lateral sclerosis. It is characterized by a slowly progressive clinical course. Signs and symptoms include muscle weakness, atrophy, and fasciculation.
  • 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 ventilator 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.
  • An autosomal dominant inherited form of amyloidosis.
  • Group of disorders marked by progressive degeneration of motor neurons in the spinal cord resulting in weakness and muscular atrophy, usually without evidence of injury to the corticospinal tracts.
  • Progressive degeneration of the neurons that give rise to the corticospinal tract and of the motor cells of the brain stem and spinal cord, resulting in a deficit of upper and lower motor neurons.
ICD-10-CM G12.21 is grouped within Diagnostic Related Group(s) (MS-DRG v37.0):
  • 056 Degenerative nervous system disorders with mcc
  • 057 Degenerative nervous system disorders without mcc

Convert G12.21 to ICD-9-CM

Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
  • 2020 (effective 10/1/2019): No change
Code annotations containing back-references to G12.21:
  • Code First: F48.2
    ICD-10-CM Diagnosis Code F48.2

    Pseudobulbar affect

      2016 2017 2018 2019 2020 Billable/Specific Code
    Applicable To
    • Involuntary emotional expression disorder
    Code First
    • underlying cause, if known, such as:
    • amyotrophic lateral sclerosis (G12.21)
    • multiple sclerosis (G35)
    • sequelae of cerebrovascular disease (I69.-)
    • sequelae of traumatic intracranial injury (S06.-)
  • Type 1 Excludes: M62.5
    ICD-10-CM Diagnosis Code M62.5

    Muscle wasting and atrophy, not elsewhere classified

      2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
    Applicable To
    • Disuse atrophy NEC
    Type 1 Excludes
    Type 2 Excludes
    • pelvic muscle wasting (N81.84)

Diagnosis Index entries containing back-references to G12.21:
  • Amyotrophia, amyotrophy, amyotrophic G71.8
    ICD-10-CM Diagnosis Code G71.8

    Other primary disorders of muscles

      2016 2017 2018 2019 2020 Billable/Specific Code
    • lateral sclerosis G12.21
  • Atrophy, atrophic (of)
    • muscle, muscular (diffuse) (general) (idiopathic) (primary) M62.50
      ICD-10-CM Diagnosis Code M62.50

      Muscle wasting and atrophy, not elsewhere classified, unspecified site

        2016 2017 2018 2019 2020 Billable/Specific Code
      • progressive (bulbar) G12.21
      • spinal G12.9
        ICD-10-CM Diagnosis Code G12.9

        Spinal muscular atrophy, unspecified

          2016 2017 2018 2019 2020 Billable/Specific Code
        • Aran-Duchenne G12.21
      • Duchenne-Aran G12.21
    • Duchenne-Aran G12.21
  • Disease, diseased - see also Syndrome
    • motor neuron (bulbar) (mixed type) (spinal) G12.20
      ICD-10-CM Diagnosis Code G12.20

      Motor neuron disease, unspecified

        2016 2017 2018 2019 2020 Billable/Specific Code
      • amyotrophic lateral sclerosis G12.21
  • Duchenne-Aran muscular atrophy G12.21
  • Paralysis, paralytic (complete) (incomplete) G83.9
    ICD-10-CM Diagnosis Code G83.9

    Paralytic syndrome, unspecified

      2016 2017 2018 2019 2020 Billable/Specific Code
    • muscle, muscular NEC G72.89
      ICD-10-CM Diagnosis Code G72.89

      Other specified myopathies

        2016 2017 2018 2019 2020 Billable/Specific Code
      • progressive G12.21
    • spinal (cord) G83.9
      ICD-10-CM Diagnosis Code G83.9

      Paralytic syndrome, unspecified

        2016 2017 2018 2019 2020 Billable/Specific Code
    • amyotrophic G12.21
  • Sclerosis, sclerotic
    • lateral (amyotrophic) (descending) (spinal) G12.21
    • spinal (cord) (progressive) G95.89
      ICD-10-CM Diagnosis Code G95.89

      Other specified diseases of spinal cord

        2016 2017 2018 2019 2020 Billable/Specific Code
      Applicable To
      • Cord bladder NOS
      • Drug-induced myelopathy
      • Radiation-induced myelopathy
      Type 1 Excludes
    • amyotrophic G12.21 (lateral)

ICD-10-CM Codes Adjacent To G12.21
G11.2 Late-onset cerebellar ataxia
G11.3 Cerebellar ataxia with defective DNA repair
G11.4 Hereditary spastic paraplegia
G11.8 Other hereditary ataxias
G11.9 Hereditary ataxia, unspecified
G12 Spinal muscular atrophy and related syndromes
G12.0 Infantile spinal muscular atrophy, type I [Werdnig-Hoffman]
G12.1 Other inherited spinal muscular atrophy
G12.2 Motor neuron disease
G12.20 …… unspecified
G12.21 Amyotrophic lateral sclerosis
G12.22 Progressive bulbar palsy
G12.23 Primary lateral sclerosis
G12.24 Familial motor neuron disease
G12.25 Progressive spinal muscle atrophy
G12.29 Other motor neuron disease
G12.8 Other spinal muscular atrophies and related syndromes
G12.9 Spinal muscular atrophy, unspecified
G13 Systemic atrophies primarily affecting central nervous system in diseases classified elsewhere
G13.0 Paraneoplastic neuromyopathy and neuropathy
G13.1 Other systemic atrophy primarily affecting central nervous system in neoplastic disease

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.