2026 ICD-10-CM Diagnosis Code R40.2440Other coma, without documented Glasgow coma scale score, or with partial score reported, unspecified time

ICD-10-CM Codes›R00–R99›R40-R46›R40

ICD-10-CM R40.2440
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R40.2440 is a billable ICD-10-CM diagnosis code for other coma, without documented Glasgow coma scale score, or with partial score reported, unspecified time. The 7th character 0 reports a Glasgow coma scale score taken at an unspecified time. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is not accepted as a principal diagnosis by the Medicare Code Editor. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. Coders also document this condition as blistering of skin due to drug-induced coma. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nervous system signs and symptoms.

Code Identity

ICD-10-CM Code
R40.2440
Billable Status
Yes — Valid for Submission
Code Describes
Other coma, without documented Glasgow coma scale score, or with partial score reported, unspecified time
Short Description
Other coma, without Glasgow, or w/part score, unsp time
Parent Code
R40.244
Other coma, without documented Glasgow coma scale score, or with partial score reported

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR40-R46Symptoms and signs involving cognition, perception, emotional state and behavior
CategoryR40Somnolence, stupor and coma
This CodeR40.2440Other coma, without documented Glasgow coma scale score, or with partial score reported, unspecified time

Code EditsBilling

Medicare Code Editor checks that affect claim validity for R40.2440.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Blistering of skin due to drug-induced coma
  • Bullae and sweat gland necrosis in drug-induced coma

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR SYM010
Nervous system signs and symptoms
Default principal diagnosis: inpatient No · outpatient No

Convert R40.2440 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
No Map There is no ICD-9 equivalent for this code.

Code History & ChangesHistory

Replacement R40.2440 replaces the following previously assigned code(s):

  • R40.244 - Oth coma,w/o Glasgow coma scale score,or w/part score report
FY 2018AddedAdded to the ICD-10-CM code setEffective October 1, 2017.
FY 2019–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About R40.2440Overview

Is R40.2440 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other coma, without documented Glasgow coma scale score, or with partial score reported, unspecified time on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character 0 in R40.2440 mean?

The final character 0 reports a Glasgow coma scale score taken at an unspecified time, in this case involving the other coma, without documented Glasgow coma scale score, or with partial score reported.

Can R40.2440 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because other coma, without documented Glasgow coma scale score, or with partial score reported, unspecified time describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.