All ICD10 Codes
Chapter 6

G00–G99: Diseases of the Nervous System

Diseases of the Nervous System diagnostic classification updated for 2026.

Chapter Instructions

Excludes2(Not included here. Code separately if applicable.)
  • 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)
All CodesBillable Only
Internal Codes
PrevNext
  • G45.3|

    Amaurosis fugax

  • G45.4|

    Transient global amnesia

  • G45.8|

    Other transient cerebral ischemic attacks and related syndromes

  • G45.9|

    Transient cerebral ischemic attack, unspecified

  • G46.0|

    Middle cerebral artery syndrome

  • G46.1|

    Anterior cerebral artery syndrome

  • G46.2|

    Posterior cerebral artery syndrome

  • G46.3|

    Brain stem stroke syndrome

  • G46.4|

    Cerebellar stroke syndrome

  • G46.5|

    Pure motor lacunar syndrome

  • G46.6|

    Pure sensory lacunar syndrome

  • G46.7|

    Other lacunar syndromes

  • G46.8|

    Other vascular syndromes of brain in cerebrovascular diseases

  • G47.00|

    Insomnia, unspecified

  • G47.01|

    Insomnia due to medical condition

  • G47.09|

    Other insomnia

  • G47.10|

    Hypersomnia, unspecified

  • G47.11|

    Idiopathic hypersomnia with long sleep time

  • G47.12|

    Idiopathic hypersomnia without long sleep time

  • G47.13|

    Recurrent hypersomnia

  • G47.14|

    Hypersomnia due to medical condition

  • G47.19|

    Other hypersomnia

  • G47.20|

    Circadian rhythm sleep disorder, unspecified type

  • G47.21|

    Circadian rhythm sleep disorder, delayed sleep phase type

  • G47.22|

    Circadian rhythm sleep disorder, advanced sleep phase type

  • G47.23|

    Circadian rhythm sleep disorder, irregular sleep wake type

  • G47.24|

    Circadian rhythm sleep disorder, free running type

  • G47.25|

    Circadian rhythm sleep disorder, jet lag type

  • G47.26|

    Circadian rhythm sleep disorder, shift work type

  • G47.27|

    Circadian rhythm sleep disorder in conditions classified elsewhere

  • G47.29|

    Other circadian rhythm sleep disorder

  • G47.30|

    Sleep apnea, unspecified

  • G47.31|

    Primary central sleep apnea

  • G47.32|

    High altitude periodic breathing

  • G47.33|

    Obstructive sleep apnea (adult) (pediatric)

  • G47.34|

    Idiopathic sleep related nonobstructive alveolar hypoventilation

  • G47.35|

    Congenital central alveolar hypoventilation syndrome

  • G47.36|

    Sleep related hypoventilation in conditions classified elsewhere

  • G47.37|

    Central sleep apnea in conditions classified elsewhere

  • G47.39|

    Other sleep apnea

  • G47.411|

    Narcolepsy with cataplexy

  • G47.419|

    Narcolepsy without cataplexy

  • G47.421|

    Narcolepsy in conditions classified elsewhere with cataplexy

  • G47.429|

    Narcolepsy in conditions classified elsewhere without cataplexy

  • G47.50|

    Parasomnia, unspecified

  • G47.51|

    Confusional arousals

  • G47.52|

    REM sleep behavior disorder

  • G47.53|

    Recurrent isolated sleep paralysis

  • G47.54|

    Parasomnia in conditions classified elsewhere

  • G47.59|

    Other parasomnia

PreviousPage 7 of 14Next