2020 ICD-10-CM Diagnosis Code G71.1

Myotonic disorders

    2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
  • G71.1 should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail.
  • The 2020 edition of ICD-10-CM G71.1 became effective on October 1, 2019.
  • This is the American ICD-10-CM version of G71.1 - other international versions of ICD-10 G71.1 may differ.
The following code(s) above G71.1 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 G71.1:
  • 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
  • G71
    ICD-10-CM Diagnosis Code G71

    Primary disorders of muscles

      2016 2017 2018 2019 2020 Non-Billable/Non-Specific Code
    Type 2 Excludes
    • arthrogryposis multiplex congenita (Q74.3)
    • metabolic disorders (E70-E88)
    • myositis (M60.-)
    Primary disorders of muscles
Clinical Information
  • An inherited or acquired, localized or generalized disorder affecting the muscles. It may be associated with abnormalities in the chloride or sodium channels of the muscles. It is characterized by delayed muscle relaxation following stimulation or contraction. Representative examples include myotonia congenita and myotonic dystrophy.
  • Diseases characterized by myotonia, which may be inherited or acquired. Myotonia may be restricted to certain muscles (e.g., intrinsic hand muscles) or occur as a generalized condition. These disorders may be associated with abnormal muscle sodium channel and chloride channels. Myotonic dystrophy and myotonia congenita represent two relatively common forms of this disorder. Proximal myotonic myopathy often presents with myotonia and muscle pain in early adulthood and later in life thigh muscle weakness and cataracts develop. (from Adams et al., Principles of Neurology, 6th ed, p1392)
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 G71.1:
  • Code First: H28
    ICD-10-CM Diagnosis Code H28

    Cataract in diseases classified elsewhere

      2016 2017 2018 2019 2020 Billable/Specific Code Manifestation Code
    Code First
    • underlying disease, such as:
    • hypoparathyroidism (E20.-)
    • myotonia (G71.1-)
    • myxedema (E03.-)
    • protein-calorie malnutrition (E40-E46)
    Type 1 Excludes
ICD-10-CM Codes Adjacent To G71.1
G70.80 Lambert-Eaton syndrome, unspecified
G70.81 Lambert-Eaton syndrome in disease classified elsewhere
G70.89 Other specified myoneural disorders
G70.9 Myoneural disorder, unspecified
G71 Primary disorders of muscles
G71.0 Muscular dystrophy
G71.00 …… unspecified
G71.01 Duchenne or Becker muscular dystrophy
G71.02 Facioscapulohumeral muscular dystrophy
G71.09 Other specified muscular dystrophies
G71.1 Myotonic disorders
G71.11 Myotonic muscular dystrophy
G71.12 Myotonia congenita
G71.13 Myotonic chondrodystrophy
G71.14 Drug induced myotonia
G71.19 Other specified myotonic disorders
G71.2 Congenital myopathies
G71.3 Mitochondrial myopathy, not elsewhere classified
G71.8 Other primary disorders of muscles
G71.9 Primary disorder of muscle, unspecified
G72 Other and unspecified myopathies

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