Alphabetic Index FY2027

R40.23

Coma scale, best motor response

FY2027Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified/R40–R46 Symptoms and signs involving cognition, perception, emotional state and behavior

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

R40.23 is a non-billable ICD-10-CM code header for coma scale, best motor response. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are R40.231 Coma scale, best motor response, none; R40.232 Coma scale, best motor response, extension; R40.233 Coma scale, best motor response, abnormal flexion; R40.234 Coma scale, best motor response, flexion withdrawal and 2 more. Its coding notes include a Code first instruction, 4 Excludes1 entries and 5 Excludes2 entries.

7th characters

Every code below needs one of these.

The following appropriate 7th character is to be added to subcategory R40.23-:

  • 0unspecified time
  • 1in the field [EMT or ambulance]
  • 2at arrival to emergency department
  • 3at hospital admission
  • 424 hours or more after hospital admission

Guidelines tips

From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.

Pressure ulcer stage, ulcer depth, BMI, NIHSS and coma scale may be coded from other clinicians' documentation. The diagnosis itself must be documented by the patient's provider.

Guidelines I.B.14Documentation by clinicians other than the providerRead the official text

Symptom and sign codes are acceptable when no definitive diagnosis has been established. They are not added for signs that are routinely associated with a diagnosis.

Guidelines I.C.18.a; I.C.18.bSymptom and sign codesRead the official text

R40.20 is for coma of unknown cause or traumatic brain injury without a documented scale. Coma scale codes are not reported for a medically induced coma or a sedated patient.

Guidelines I.C.18.eComa and the Glasgow coma scaleRead the official text

Code first

If the underlying condition listed here is present and known, sequence it first.

Inherited from R40.2 Coma
  • any associated:
    • fracture of skull (S02.-)
    • intracranial injury (S06.-)

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from R40 Somnolence, stupor and coma
  • 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)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

Also from chapter/block level (5 notes)
Inherited from R40–R46 Symptoms and signs involving cognition, perception, emotional state and behavior
  • symptoms and signs constituting part of a pattern of mental disorder (F01-F99)
Inherited from Chapter 18 Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
  • abnormal findings on antenatal screening of mother (O28.-)
  • certain conditions originating in the perinatal period (P04-P96)
  • signs and symptoms classified in the body system chapters
  • signs and symptoms of breast (N63, N64.5)

Notes

Inherited from R40.2 Coma
  • One code from each subcategory, R40.21-R40.23, is required to complete the coma scale
Also from chapter/block level (9 notes)
Inherited from Chapter 18 Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
  • This chapter includes symptoms, signs, abnormal results of clinical or other investigative procedures, and ill-defined conditions regarding which no diagnosis classifiable elsewhere is recorded.
  • 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-R94 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 diagnosis 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.

More specific codes under R40.23 6