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ICD-10-CM 2027 diagnosis code

R40.2Coma

Not billable — use a more specific code

R40.2 is a header code, so it can't be reported by itself. Choose one of the 6 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About R40.2

R40.2 is the ICD-10-CM diagnosis code for coma. It belongs to category R40 (Somnolence, stupor and coma), block R40-R46 (symptoms and signs involving cognition, perception, emotional state and behavior) and chapter 18 (symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified). It is a header code, so it can't be reported by itself; one of its 6 subcodes must be used instead.

Within R40 (Somnolence, stupor and coma), R40.2 is specifically for coma. Related codes cover Somnolence (R40.0), stupor (R40.1), persistent vegetative state (R40.3) and transient alteration of awareness (R40.4).

To report this condition, pick the subcode that matches the documentation: R40.20 (coma), R40.21 (scale, eyes open), R40.22 (scale, best verbal response), R40.23 (scale, best motor response), R40.24 (score) and R40.2A (condition).

Code first any associated: fracture of skull (S02.-) and intracranial injury (S06.-).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under R40.2

Coding notes

Note
  • One code from each subcategory, R40.21-R40.23, is required to complete the coma scale
Code firstSequence the underlying condition first
  • any associated:
  • fracture of skull (S02.-)
  • intracranial injury (S06.-)

Notes that apply from higher levels

Instructions written at a parent level also apply to R40.2.

› From R40 Somnolence, stupor and coma
Excludes1
  • neonatal coma (P91.5)
  • somnolence, stupor and coma in diabetes (E08-E13)
  • somnolence, stupor and coma in hepatic failure (K72.-)
  • somnolence, stupor and coma in hypoglycemia (nondiabetic) (E15)

Broader instructions also apply from R40-R46 Symptoms and signs involving cognition, perception, emotional state and behavior and Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified.

Codes whose notes reference R40.2

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about R40.2

Is R40.2 billable?

No. R40.2 is a header code. Report one of its more specific subcodes instead.