R40.2 ICD-10-CA subcategory: Coma, unspecified

R40.2 isn’t a code on its own. Choose one of the 2 codes beneath it, the one the documentation supports.

Official description

R40.2

Coma, unspecified

ICD-10-CA · Canada · Also written R402

Codes in R40.2

R40.2 isn’t a code on its own. Open the code that matches what the note documents.

Notes for R40.2

As CIHI prints them, with any note R40.2 takes from the headings above it.

Excludes

Conditions classified elsewhere.

Note

  • Signs and symptoms that point rather definitely to a given diagnosis have been assigned to a category in other chapters of the classification. In general, categories in this chapter include the less well-defined conditions and symptoms that, without the necessary study of the case to establish a final diagnosis, point perhaps equally to two or more diseases or to two or more systems of the body. Practically all categories in the chapter could be designated "not otherwise specified", "unknown etiology" or "transient". The Alphabetical Index should be consulted to determine which symptoms and signs are to be allocated here and which to other chapters. The residual subcategories, numbered .8, are generally provided for other relevant symptoms that cannot be allocated elsewhere in the classification.The conditions and signs or symptoms included in categories (R00-R99) consist of:(a) cases for which no more specific diagnosis can be made even after all the facts bearing on the case have been investigated;(b) signs or symptoms existing at the time of initial encounter that proved to be transient and whose causes could not be determined;(c) provisional diagnoses in a patient who failed to return for further investigation or care;(d) cases referred elsewhere for investigation or treatment before the diagnosis was made;(e) cases in which a more precise diagnosis was not available for any other reason;(f) certain symptoms, for which supplementary information is provided, that represent important problems in medical care in their own right.From Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)

Where R40.2 sits

  1. 1ChapterChapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
  2. 2Block R40-R46Symptoms and signs involving cognition, perception, emotional state and behaviour
  3. 3Category R40Somnolence, stupor and coma
  4. 4Subcategory R40.2Coma, unspecified

Source and release

Data release
ICD-10-CA · FY 2026–2027
Effective date
Apr 1, 2026
Publisher
CIHI

This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.

Frequently asked questions

Is R40.2 a valid ICD-10-CA code?

No. R40.2 (Coma, unspecified) is a subcategory heading in CIHI’s ICD-10-CA FY 2026–2027 release. It holds 2 codes; record the one the documentation supports.

Where is R40.2 in ICD-10-CA?

R40.2 sits under R40 Somnolence, stupor and coma, within R40-R46 Symptoms and signs involving cognition, perception, emotional state and behaviour, within Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99).

What coding notes apply to R40.2?

ICD-10-CA lists Excludes, Note notes for R40.2, including those from the headings it sits under. They are listed on this page with where each one comes from.

Which ICD-10-CA release does this page use?

It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.