R64 ICD-10-CM Code: Cachexia
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99) / General symptoms and signs (R50-R69)
R64
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceCachexia
Severe wasting and loss of muscle mass and body weight, often seen in advanced cancer, chronic illness, or severe malnutrition.
Buddy Insight
Cachexia represents severe protein-energy malnutrition with significant muscle wasting that dramatically increases morbidity and mortality risk.
CMS-HCC V28
N/A—
Not mapped
CMS-HCC V24
MappedHCC 21
RAF 0.455
ACA/HHS
MappedHCC 23
Varies by metal level
ESRD/PACE
MappedHCC 21
RAF 0.068
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for R64 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for R64 in this effective period.
Related Child Codes
ICD-10-CM does not list child codes under R64 for this display context.
Includes
OfficialICD-10-CM does not list Includes notes for R64 in this effective period.
Excludes 1
Official- abnormal weight loss (R63.4)
- cachexia due to underlying condition (E88.A)
- nutritional marasmus (E41)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for R64 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for R64 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for R64 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is R64 an HCC code?
Yes. R64 maps to Protein-Calorie Malnutrition under the V24 model but is not retained in V28.
HCC Category Mapping
Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
Work R64 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for R64
For R64to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed R64 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
Get the V28 RAF + MEAT cheat sheet
One printable page: confirm a code's V28 HCC status, its RAF weight, and the MEAT your note needs to make it stick. Free, no card.
Free PDF. No card. Unsubscribe anytime.
What This Code Means
R64 is the ICD-10-CM diagnosis code for cachexia. Severe wasting and loss of muscle mass and body weight, often seen in advanced cancer, chronic illness, or severe malnutrition. R64 sits in the ICD-10-CM chapter for symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (r00-r99), within the section covering general symptoms and signs (r50-r69).
Under the older CMS-HCC V24 model, R64 maps to Protein-Calorie Malnutrition (HCC 21) with a community, non-dual, aged base RAF weight of 0.455. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Cachexia is a sign of serious underlying disease; always investigate and code the primary condition. Because R64 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for R64 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Cachexia is a sign of serious underlying disease; always investigate and code the primary condition
- •Document the degree of weight loss and functional decline to support medical necessity
Clinical Significance
Cachexia represents severe protein-energy malnutrition with significant muscle wasting that dramatically increases morbidity and mortality risk. This condition indicates advanced disease state requiring intensive nutritional intervention and impacts multiple body systems and functional status.
Documentation Requirements
- ✓Documentation of severe weight loss (>5% in 6 months)
- ✓Evidence of muscle wasting and weakness
- ✓Underlying disease process causing cachexia
- ✓Nutritional assessment results
- ✓Functional status decline
- ✓Laboratory values showing protein deficiency
- ✓Interventions attempted for nutritional support
- ✓Prognosis and goals of care discussions