2027 ICD-10-CM Diagnosis Code R46.4Slowness and poor responsiveness

ICD-10-CM Codes›R00–R99›R40-R46›R46

ICD-10-CM R46.4
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

R46.4 is a billable ICD-10-CM diagnosis code for slowness and poor responsiveness. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 951. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Symptoms of mental and substance use conditions.

Code Identity

ICD-10-CM Code
R46.4
Billable Status
Yes — Valid for Submission
Code Describes
Slowness and poor responsiveness
Short Description
Slowness and poor responsiveness
Same as the full description in the CMS dataset.
Parent Code
R46
Symptoms and signs involving appearance and behavior

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
CategoryR46Symptoms and signs involving appearance and behavior
This CodeR46.4Slowness and poor responsiveness

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Slowness and poor responsiveness

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to R46.4: its own notes plus those printed at R46, block R40-R46, and Chapter 18. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

On R46.4 itself
From R46 Symptoms and signs involving appearance and behavior applies to 10 codes
  • appearance and behavior in schizophrenia, schizotypal and delusional disorders (F20-F29)
  • mental and behavioral disorders (F01-F99)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block R40-R46 Symptoms and signs involving cognition, perception, emotional state and behavior applies to 157 codes
  • symptoms and signs constituting part of a pattern of mental disorder (F01-F99)
From Chapter 18 (R00-R99) Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified applies to 774 codes
  • 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

General instructions on how these codes are used.

From Chapter 18 (R00-R99) Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified applies to 774 codes
  • 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.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR SYM008
Symptoms of mental and substance use conditions
Default principal diagnosis: inpatient Yes · outpatient Yes

Convert R46.4 to ICD-9-CMHistory

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

ICD-9-CM
799.89 Ill-define condition NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About R46.4Overview

What is the ICD-10 code for slowness and poor responsiveness?

The ICD-10-CM code for slowness and poor responsiveness is R46.4 (sometimes written as R464). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is R46.4 (Symptoms and signs involving appearance and behavior) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report slowness and poor responsiveness on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does R46.4 group to?

When slowness and poor responsiveness is the principal diagnosis on an inpatient stay, it groups to MS-DRG 951 (other Factors Influencing Health Status), which carries a relative weight of 0.5574. Higher weights mean higher Medicare reimbursement.

Can R46.4 be a principal diagnosis?

Use it with care. This is a symptom code, so once a definitive diagnosis explaining the slowness and poor responsiveness is established, that condition takes the principal position instead.

Can R46.4 be reported with R40.1?

Not as a rule. The Excludes1 note on R46.4 lists "stupor (R40.1)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).