ICD-10 Diagnosis Code R40.20

Unspecified coma

Diagnosis Code R40.20

ICD-10: R40.20
Short Description: Unspecified coma
Long Description: Unspecified coma
This is the 2018 version of the ICD-10-CM diagnosis code R40.20

Valid for Submission
The code R40.20 is valid for submission for HIPAA-covered transactions.

Replaced Code Additional informationCallout TooltipReplaced Code
The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2017. This codes was replaced for the FY 2018 (October 1, 2017-September 30, 2018).

This code was replaced in the 2018 ICD-10 code set with the code(s) listed below.
  • E11.11 - Type 2 diabetes mellitus with ketoacidosis with coma

Code Classification
  • Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00–R99)
    • Symptoms and signs involving cognition, perception, emotional state and behavior (R40-R46)
      • Somnolence, stupor and coma (R40)

Information for Medical Professionals

According to ICD-10-CM guidelines this code should not to be used as a principal diagnosis code when a related definitive diagnosis has been established.
Convert to ICD-9 Additional informationCallout TooltipGeneral Equivalence Map
The ICD-10 and ICD-9 GEMs are used to facilitate linking between the diagnosis codes in ICD-9-CM and the new ICD-10-CM code set. The GEMs are the raw material from which providers, health information vendors and payers can derive specific applied mappings to meet their needs.

  • Alcoholic coma
  • Blistering of skin due to coma
  • Blistering of skin due to drug-induced coma
  • Blistering of skin induced by prolonged pressure
  • Coma
  • Coma associated with malnutrition-related diabetes mellitus
  • Drug-induced coma
  • Drug-induced coma
  • Hypothermic coma
  • Hypoxic-ischemic coma
  • Hypoxic-ischemic coma
  • Irreversible coma
  • Ischemic stroke
  • Ischemic stroke with coma
  • Monocular movements in coma
  • Neurological disorder associated with malnutrition-related diabetes mellitus
  • On examination - comatose
  • On examination - unconscious/comatose
  • Pituitary coma
  • Post-anoxic coma
  • Post-cardiorespiratory arrest coma
  • Post-ictal coma
  • Post-traumatic coma
  • Skin lesion due to drug overdose
  • Spontaneous eye movements in coma
  • Spontaneous eye movements in coma
  • Unconscious
  • Unconscious
  • Unresponsive
  • Uremic coma
  • Uremic encephalopathy

Index of Diseases and Injuries
References found for the code R40.20 in the Index of Diseases and Injuries:

Information for Patients


A coma is a deep state of unconsciousness. An individual in a coma is alive but unable to move or respond to his or her environment. Coma may occur as a complication of an underlying illness, or as a result of injuries, such as brain injury.

A coma rarely lasts more than 2 to 4 weeks. The outcome for coma depends on the cause, severity, and site of the damage. People may come out of a coma with physical, intellectual, and psychological problems. Some people may remain in a coma for years or even decades. For those people, the most common cause of death is infection, such as pneumonia.

NIH: National Institute of Neurological Disorders and Stroke

  • EEG (Medical Encyclopedia)

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