R40 – Somnolence, stupor and coma

ICD-10-CM 2027 diagnosis code · Symptoms and signs involving cognition, perception, emotional state and behavior

Non-billable header

ICD-10-CM code R40

Code: R40 (claims format: R40)
Description: Somnolence, stupor and coma
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 18. Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
Block: R40-R46 Symptoms and signs involving cognition, perception, emotional state and behavior

Billable codes under R40

R40 is a header code and cannot be used on claims. Choose the most specific code:

R40.0 – SomnolenceBillable
R40.1 – StuporBillable
R40.2 – ComaHeader (more codes below)
R40.3 – Persistent vegetative stateBillable
R40.4 – Transient alteration of awarenessBillable

Notes for R40

Excludes1 (not coded here):

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)

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Block R40-R46

Excludes2 (not included here):

symptoms and signs constituting part of a pattern of mental disorder (F01-F99)

Frequently asked questions

What is ICD-10 code R40?

R40 is the ICD-10-CM code for somnolence, stupor and coma, in the block R40-R46 (Symptoms and signs involving cognition, perception, emotional state and behavior).

Is R40 a billable code?

No. R40 is a header code with more specific child codes; report one of the billable codes listed above.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.