ICD-10-CM 2027 diagnosis code
R40.2131Coma scale, eyes open, to sound, in the field [EMT or ambulance]
R40.2131 is a valid, billable ICD-10-CM code for coma scale, eyes open, to sound, in the field [emt or ambulance]. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Coma scale, eyes open, to sound, in the field
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 R40.2131
R40.2131 is the ICD-10-CM diagnosis code for coma scale, eyes open, to sound, in the field [EMT or ambulance]. 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 billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.
The 7th character "1" means in the field [EMT or ambulance].
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 951 (Other Factors Influencing Health Status, relative weight 0.5577), in MDC 23 (Factors Influencing Health Status and Other Contacts with Health Services), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
It is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
7th character
1in the field [EMT or ambulance]
Other encounter types for R40.213:
Notes that apply from higher levels
Instructions written at a parent level also apply to R40.2131.
› From R40.2 Coma
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.
MS-DRG v44.0 grouping
All DRGs →Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.
MDC 23 · Factors Influencing Health Status and Other Contacts with Health Services
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about R40.2131
Is R40.2131 billable?
- Yes. R40.2131 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
What does the "1" at the end of R40.2131 mean?
- It is the 7th character for in the field [EMT or ambulance].
Can R40.2131 be used as a principal diagnosis?
- No. It is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.
Is R40.2131 a CC or MCC?
- No. R40.2131 is neither a CC nor an MCC under MS-DRG v44.0.
What DRG does R40.2131 group to?
- R40.2131 is used in the MS-DRG v44.0 logic for MS-DRG 951 (Other Factors Influencing Health Status). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.