E75.21
BillableFabry (-Anderson) disease
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E75.21 an HCC code?
Yes. E75.21 maps to Lysosomal Storage Disorders under the CMS-HCC V28 risk adjustment model (and Other Significant Endocrine and Metabolic Disorders under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.
MEAT Criteria for E75.21
For E75.21 to 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 E75.21 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E75.21 is the ICD-10-CM diagnosis code for fabry (-anderson) disease. Fabry disease is a rare inherited metabolic disorder where the body cannot properly break down certain fatty substances, leading to their buildup in cells and tissues throughout the body, causing pain, kidney problems, and heart issues. E75.21 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).
Under the CMS-HCC V28 risk adjustment model, E75.21 maps to Lysosomal Storage Disorders (HCC 49) with a community, non-dual, aged base RAF weight of 0.226. Under the older CMS-HCC V24 model, E75.21 maps to Other Significant Endocrine and Metabolic Disorders (HCC 23) with a community, non-dual, aged base RAF weight of 0.230. 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.
This is a lysosomal storage disorder; ensure documentation specifies Fabry or Fabry-Anderson disease. Because E75.21 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 E75.21 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a lysosomal storage disorder; ensure documentation specifies Fabry or Fabry-Anderson disease
- •Consider coding associated complications such as kidney disease, cardiac manifestations, or neuropathic pain separately if documented
Clinical Significance
Fabry disease (Fabry-Anderson disease) is an X-linked lysosomal storage disorder caused by alpha-galactosidase A deficiency, leading to progressive accumulation of globotriaosylceramide (Gb3) in blood vessel walls and organs. It causes severe neuropathic pain, progressive kidney disease, cardiac hypertrophy, stroke, and premature death. Enzyme replacement therapy and oral chaperone therapy can slow disease progression.
Documentation Requirements
- ✓Confirmed diagnosis of Fabry disease or alpha-galactosidase A deficiency
- ✓Alpha-galactosidase A enzyme assay results (low in affected males; may be normal in carrier females)
- ✓GLA gene mutation analysis
- ✓Organ involvement assessment: renal function (GFR, proteinuria), cardiac evaluation (echocardiogram, MRI), cerebrovascular screening
- ✓Current treatment status: enzyme replacement therapy (agalsidase alfa or beta) or chaperone therapy (migalastat)
- ✓Pain assessment and neuropathy evaluation