2026 ICD-10-CM Diagnosis Code R64Cachexia

ICD-10-CM Codes›R00–R99›R50-R69›R64

ICD-10-CM R64
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

R64 is a billable ICD-10-CM diagnosis code for cachexia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 947 through 948. 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 Other general signs and symptoms.

Code Identity

ICD-10-CM Code
R64
Billable Status
Yes — Valid for Submission
Code Describes
Cachexia
Chapter
R50-R69
General symptoms and signs

Code Classification

ChapterR00–R99Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
SectionR50-R69General symptoms and signs
CategoryR64Cachexia
This CodeR64Cachexia

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormal weight loss
  • Abnormal weight loss associated with AIDS
  • AIDS wasting syndrome
  • Cachexia
  • Cachexia associated with AIDS
  • Café au lait spots
  • Cardiac cachexia
  • Diffuse dermatitis
  • Distribution of body fat loss - finding
  • Emaciated
  • Facial dysmorphism, anorexia, cachexia, eye and skin anomalies syndrome
  • Inanition
  • Malignant cachexia
  • Muscle cachexia
  • Severe dermatitis, multiple allergies, metabolic wasting syndrome
  • Severe systemic illness tissue wasting
  • Weight decreased

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 1 Excludes

  • abnormal weight loss R63.4
  • cachexia due to underlying condition E88.A
  • nutritional marasmus E41

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Cachexia
    • Cachexia
      • cancerous
    • Cachexia
      • malignant
    • Cachexia
      • pulmonary
    • Emaciation
    • Inanition

Clinical ClassificationClinical

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

CCSR SYM016
Other general signs and symptoms
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Cachexia

    general ill health, malnutrition, and weight loss, usually associated with chronic disease.

Patient EducationClinical

Malnutrition

Malnutrition means that your body isn't getting enough calories or the right balance of nutrients to stay healthy. This can happen if you don't get enough protein, carbohydrates, and fats, eat too much unhealthy food, or don't get the vitamins and minerals your body needs.

The full article covers:

  • What is malnutrition?
  • What are the types of malnutrition?
  • What causes malnutrition?
  • Who is at risk for developing malnutrition?
  • What are the symptoms of malnutrition?
  • How is malnutrition diagnosed?
  • What are the treatments for malnutrition?
  • Can malnutrition be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert R64 to ICD-9-CMHistory

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

ICD-9-CM
799.4 Cachexia
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About R64Overview

Is R64 (Cachexia) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report cachexia on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does R64 group to?

When cachexia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 947, 948, with relative weights from 0.8005 to 1.2694 depending on complications. Higher weights mean higher Medicare reimbursement.

Can R64 be a principal diagnosis?

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

What is the ICD-9 equivalent of R64?

Under the General Equivalence Mappings, cachexia converts to ICD-9-CM 799.4 (cachexia). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.