2027 ICD-10-CM Diagnosis Code R63.4Abnormal weight loss
ICD-10-CM Codes›R00–R99›R50-R69›R63
- Billable — Valid for Submission
- Not Chronic
R63.4 is a billable ICD-10-CM diagnosis code for abnormal weight loss. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 640 through 641. 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 abnormal intentional weight loss. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other general signs and symptoms.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Abnormal intentional weight loss
- Abnormal weight loss
- Abnormal weight loss associated with AIDS
- Excessive weight loss
- Intentional weight loss
- Unexplained weight loss
- Unintentional weight loss
- Weight decreased
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to R63.4: its own notes plus those printed at R63 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.
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.
Notes
General instructions on how these codes are used.
- 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.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name R63.4, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming R63.4: they are not reported together with it, unless the two conditions are unrelated.
Use Additional Code 1
These codes say to use an additional code from the note, and R63.4 is one of the codes named.
- U07.0 Vaping-related disorderweight loss (R63.4)
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Abnormal, abnormality, abnormalities See Also: Anomaly;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Abnormal Weight Loss
unexplained or unintentional weight loss.
Convert R63.4 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About R63.4Overview
What is the ICD-10 code for abnormal weight loss?
The ICD-10-CM code for abnormal weight loss is R63.4 (sometimes written as R634). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is R63.4 (Symptoms and signs concerning food and fluid intake) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report abnormal weight loss on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does R63.4 group to?
When abnormal weight loss is the principal diagnosis on an inpatient stay, it groups to MS-DRG 641, 640, with relative weights from 0.7864 to 1.3392 depending on complications. Higher weights mean higher Medicare reimbursement.
Can R63.4 be a principal diagnosis?
Use it with care. This is a symptom code, so once a definitive diagnosis explaining the abnormal weight loss is established, that condition takes the principal position instead.
Can R63.4 be reported with a code from F50.2?
Not as a rule. The Excludes1 note at R63, which applies to R63.4, lists "bulimia NOS (F50.2-)". 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).
