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  6. 2024 ICD-10-CM Code R40.2
Version 2024
Non-Billable Code
No Valid Principal Dx

2024 ICD-10-CM Diagnosis Code R40.2

Coma

ICD-10-CM Code:
R40.2
ICD-10 Code for:
Coma
Is Billable?
Not Valid for Submission
Code Navigator:

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)

R40.2 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of coma. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

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.

Specific Coding Applicable to Coma

Non-specific codes like R40.2 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for coma:

  • Use R40.20 for Unspecified coma - BILLABLE CODE

  • R40.21 for Coma scale, eyes open - NON-BILLABLE CODE

  • R40.211 for Coma scale, eyes open, never - NON-BILLABLE CODE

  • Use R40.2110 for unspecified time - BILLABLE CODE

  • Use R40.2111 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2112 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2113 for at hospital admission - BILLABLE CODE

  • Use R40.2114 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.212 for Coma scale, eyes open, to pain - NON-BILLABLE CODE

  • Use R40.2120 for unspecified time - BILLABLE CODE

  • Use R40.2121 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2122 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2123 for at hospital admission - BILLABLE CODE

  • Use R40.2124 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.213 for Coma scale, eyes open, to sound - NON-BILLABLE CODE

  • Use R40.2130 for unspecified time - BILLABLE CODE

  • Use R40.2131 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2132 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2133 for at hospital admission - BILLABLE CODE

  • Use R40.2134 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.214 for Coma scale, eyes open, spontaneous - NON-BILLABLE CODE

  • Use R40.2140 for unspecified time - BILLABLE CODE

  • Use R40.2141 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2142 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2143 for at hospital admission - BILLABLE CODE

  • Use R40.2144 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.22 for Coma scale, best verbal response - NON-BILLABLE CODE

  • R40.221 for Coma scale, best verbal response, none - NON-BILLABLE CODE

  • Use R40.2210 for unspecified time - BILLABLE CODE

  • Use R40.2211 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2212 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2213 for at hospital admission - BILLABLE CODE

  • Use R40.2214 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.222 for Coma scale, best verbal response, incomprehensible words - NON-BILLABLE CODE

  • Use R40.2220 for unspecified time - BILLABLE CODE

  • Use R40.2221 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2222 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2223 for at hospital admission - BILLABLE CODE

  • Use R40.2224 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.223 for Coma scale, best verbal response, inappropriate words - NON-BILLABLE CODE

  • Use R40.2230 for unspecified time - BILLABLE CODE

  • Use R40.2231 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2232 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2233 for at hospital admission - BILLABLE CODE

  • Use R40.2234 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.224 for Coma scale, best verbal response, confused conversation - NON-BILLABLE CODE

  • Use R40.2240 for unspecified time - BILLABLE CODE

  • Use R40.2241 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2242 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2243 for at hospital admission - BILLABLE CODE

  • Use R40.2244 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.225 for Coma scale, best verbal response, oriented - NON-BILLABLE CODE

  • Use R40.2250 for unspecified time - BILLABLE CODE

  • Use R40.2251 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2252 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2253 for at hospital admission - BILLABLE CODE

  • Use R40.2254 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.23 for Coma scale, best motor response - NON-BILLABLE CODE

  • R40.231 for Coma scale, best motor response, none - NON-BILLABLE CODE

  • Use R40.2310 for unspecified time - BILLABLE CODE

  • Use R40.2311 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2312 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2313 for at hospital admission - BILLABLE CODE

  • Use R40.2314 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.232 for Coma scale, best motor response, extension - NON-BILLABLE CODE

  • Use R40.2320 for unspecified time - BILLABLE CODE

  • Use R40.2321 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2322 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2323 for at hospital admission - BILLABLE CODE

  • Use R40.2324 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.233 for Coma scale, best motor response, abnormal flexion - NON-BILLABLE CODE

  • Use R40.2330 for unspecified time - BILLABLE CODE

  • Use R40.2331 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2332 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2333 for at hospital admission - BILLABLE CODE

  • Use R40.2334 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.234 for Coma scale, best motor response, flexion withdrawal - NON-BILLABLE CODE

  • Use R40.2340 for unspecified time - BILLABLE CODE

  • Use R40.2341 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2342 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2343 for at hospital admission - BILLABLE CODE

  • Use R40.2344 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.235 for Coma scale, best motor response, localizes pain - NON-BILLABLE CODE

  • Use R40.2350 for unspecified time - BILLABLE CODE

  • Use R40.2351 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2352 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2353 for at hospital admission - BILLABLE CODE

  • Use R40.2354 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.236 for Coma scale, best motor response, obeys commands - NON-BILLABLE CODE

  • Use R40.2360 for unspecified time - BILLABLE CODE

  • Use R40.2361 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2362 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2363 for at hospital admission - BILLABLE CODE

  • Use R40.2364 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.24 for Glasgow coma scale, total score - NON-BILLABLE CODE

  • R40.241 for Glasgow coma scale score 13-15 - NON-BILLABLE CODE

  • Use R40.2410 for unspecified time - BILLABLE CODE

  • Use R40.2411 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2412 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2413 for at hospital admission - BILLABLE CODE

  • Use R40.2414 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.242 for Glasgow coma scale score 9-12 - NON-BILLABLE CODE

  • Use R40.2420 for unspecified time - BILLABLE CODE

  • Use R40.2421 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2422 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2423 for at hospital admission - BILLABLE CODE

  • Use R40.2424 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.243 for Glasgow coma scale score 3-8 - NON-BILLABLE CODE

  • Use R40.2430 for unspecified time - BILLABLE CODE

  • Use R40.2431 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2432 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2433 for at hospital admission - BILLABLE CODE

  • Use R40.2434 for 24 hours or more after hospital admission - BILLABLE CODE

  • R40.244 for Other coma, without documented Glasgow coma scale score, or with partial score reported - NON-BILLABLE CODE

  • Use R40.2440 for unspecified time - BILLABLE CODE

  • Use R40.2441 for in the field [EMT or ambulance] - BILLABLE CODE

  • Use R40.2442 for at arrival to emergency department - BILLABLE CODE

  • Use R40.2443 for at hospital admission - BILLABLE CODE

  • Use R40.2444 for 24 hours or more after hospital admission - BILLABLE CODE

  • Use R40.2A for Nontraumatic coma due to underlying condition - BILLABLE CODE

Clinical Information

  • Akinetic Mutism

    a syndrome characterized by a silent and inert state without voluntary motor activity despite preserved sensorimotor pathways and vigilance. bilateral frontal lobe dysfunction involving the anterior cingulate gyrus and related brain injuries are associated with this condition. this may result in impaired abilities to communicate and initiate motor activities. (from adams et al., principles of neurology, 6th ed, p348; fortschr neurol psychiatr 1995 feb;63(2):59-67)

  • Brain Death

    a state of prolonged irreversible cessation of all brain activity, including lower brain stem function with the complete absence of voluntary movements, responses to stimuli, brain stem reflexes, and spontaneous respirations. reversible conditions which mimic this clinical state (e.g., sedative overdose, hypothermia, etc.) are excluded prior to making the determination of brain death. (from adams et al., principles of neurology, 6th ed, pp348-9)

  • Coma

    a profound state of unconsciousness associated with depressed cerebral activity from which the individual cannot be aroused. coma generally occurs when there is dysfunction or injury involving both cerebral hemispheres or the brain stem reticular formation.

  • Coma, Post-Head Injury

    prolonged unconsciousness from which the individual cannot be aroused, associated with traumatic injuries to the brain. this may be defined as unconsciousness persisting for 6 hours or longer. coma results from injury to both cerebral hemispheres or the reticular formation of the brain stem. contributing mechanisms include diffuse axonal injury and brain edema. (from j neurotrauma 1997 oct;14(10):699-713)

  • Comamonadaceae

    a family of gram-negative aerobic bacteria in the order burkholderiales, encompassing the acidovorans rrna complex. some species are pathogenic to plants.

  • Comamonas

    a genus of gram-negative, straight or slightly curved rods which are motile by polar flagella and which accumulate poly-beta-hydroxybutyrate within the cells.

  • Comamonas testosteroni

    a species of gram-negative, aerobic rods formerly called pseudomonas testosteroni. it is differentiated from other comamonas species by its ability to assimilate testosterone and to utilize phenylacetate or maleate as carbon sources.

  • Convulsive Therapy

    convulsions induced in order to treat mental disorders. it is used primarily in the treatment of severe affective disorders and schizophrenia.

  • Delftia acidovorans

    a species of gram-negative rod-shaped bacteria found ubiquitously and formerly called comamonas acidovorans and pseudomonas acidovorans. it is the type species of the genus delftia.

  • Diabetic Coma

    a state of unconsciousness as a complication of diabetes mellitus. it occurs in cases of extreme hyperglycemia or extreme hypoglycemia as a complication of insulin therapy.

  • Glasgow Coma Scale

    a scale that assesses the response to stimuli in patients with craniocerebral injuries. the parameters are eye opening, motor response, and verbal response.

  • Hepatic Encephalopathy

    a syndrome characterized by central nervous system dysfunction in association with liver failure, including portal-systemic shunts. clinical features include lethargy and confusion (frequently progressing to coma); asterixis; nystagmus, pathologic; brisk oculovestibular reflexes; decorticate and decerebrate posturing; muscle spasticity; and bilateral extensor plantar reflexes (see reflex, babinski). electroencephalography may demonstrate triphasic waves. (from adams et al., principles of neurology, 6th ed, pp1117-20; plum & posner, diagnosis of stupor and coma, 3rd ed, p222-5)

  • Hyperglycemic Hyperosmolar Nonketotic Coma

    a serious complication of type 2 diabetes mellitus. it is characterized by extreme hyperglycemia; dehydration; serum hyperosmolarity; and depressed consciousness leading to coma in the absence of ketosis and acidosis.

  • Insulin Coma

    severe hypoglycemia induced by a large dose of exogenous insulin resulting in a coma or profound state of unconsciousness from which the individual cannot be aroused.

  • Santalaceae

    a plant family of the order santalales, subclass rosidae, class magnoliopsida. they are parasites that form connections (haustoria) to their hosts to obtain water and nutrients. the one-seeded fruit may be surrounded by a brightly colored nut-like structure.

  • Frontal Lobe

    the part of the cerebral hemisphere anterior to the central sulcus, and anterior and superior to the lateral sulcus.

  • Reticular Formation

    a region extending from the pons & medulla oblongata through the mesencephalon, characterized by a diversity of neurons of various sizes and shapes, arranged in different aggregations and enmeshed in a complicated fiber network.

  • Delftia

    a genus of gram-negative, strictly aerobic chemoorganotrophic bacteria, in the family comamonadaceae.

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Code First

Code First
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
  • any associated:
  • fracture of skull S02
  • intracranial injury S06

Patient Education


Coma

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


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.