2026 ICD-10-CM Diagnosis Code R64Cachexia
ICD-10-CM Codes›R00–R99›R50-R69›R64
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Chronic Condition
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 secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 40 closely related codes. 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.
R64 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 21 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 21, ESRD (V21) category 21, and ESRD (V24) category 21 for payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
R64 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
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
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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.
Code HistoryHistory
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.
Is R64 a CC or MCC?
CMS lists R64 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 40 closely related codes in its exclusion list.
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.
Does R64 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage. R64 mapped to HCC 21 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 21 (Protein-Calorie Malnutrition), ESRD (V21) category 21 (Protein-Calorie Malnutrition), and ESRD (V24) category 21 (Protein-Calorie Malnutrition).
