E75.25
BillableMetachromatic leukodystrophy
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E75.25 an HCC code?
No. E75.25 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
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 E75.25
For E75.25 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 E75.25 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E75.25 is the ICD-10-CM diagnosis code for metachromatic leukodystrophy. Metachromatic leukodystrophy is a rare inherited metabolic disorder affecting the nervous system where the body cannot break down certain fatty substances in nerve cells, leading to progressive loss of neurological function and demyelination. E75.25 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).
E75.25 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Does not map to any HCC in V24, V28, or ESRD models. Maps only to RxHCC 41 (Rheumatoid Arthritis and Specified Autoimmune Disorders). Despite being a progressive, often fatal condition, this code carries no primary RAF weight in standard CMS-HCC models.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E75.25 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document the form of metachromatic leukodystrophy if specified (late infantile, juvenile, or adult) as this affects disease progression
- •Code associated neurological manifestations such as developmental regression, seizures, or motor decline separately if documented
Clinical Significance
Metachromatic leukodystrophy is a severe lysosomal storage disorder caused by arylsulfatase A deficiency, leading to progressive demyelination of the central and peripheral nervous systems. The late infantile form is most common, causing rapid motor and cognitive decline, while juvenile and adult forms progress more slowly. Gene therapy (atidarsagene autotemcel) has recently been approved for pre-symptomatic patients.
Documentation Requirements
- ✓Confirmed diagnosis of metachromatic leukodystrophy
- ✓Arylsulfatase A enzyme assay showing deficiency
- ✓ARSA gene mutation analysis
- ✓Form specification: late infantile, juvenile, or adult onset
- ✓Brain MRI showing white matter demyelination pattern
- ✓Nerve conduction studies documenting peripheral neuropathy
- ✓Treatment status including gene therapy eligibility assessment