E75.4
BillableNeuronal ceroid lipofuscinosis
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E75.4 an HCC code?
No. E75.4 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 E75.4
For E75.4 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 E75.4 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E75.4 is the ICD-10-CM diagnosis code for neuronal ceroid lipofuscinosis. A group of rare inherited neurological disorders characterized by progressive accumulation of lipofuscin (a fatty pigment) in nerve cells, causing progressive dementia and loss of function. E75.4 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).
E75.4 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.
E75.4 maps only to RxHCC 41 (Rheumatoid Arthritis and Specified Autoimmune Disorders) with no RAF weight. It does not map to any CMS-HCC under V24 or V28 models for Medicare Advantage risk adjustment. Despite the severity of this condition, it does not generate a direct RAF score impact in MA payment models.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E75.4 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document the age of onset and clinical presentation (infantile, late infantile, juvenile, or adult form)
- •Link to associated symptoms such as vision loss, seizures, or cognitive decline
Clinical Significance
Neuronal ceroid lipofuscinosis (NCL) encompasses a group of inherited neurodegenerative lysosomal storage disorders characterized by progressive accumulation of autofluorescent lipopigments in neurons and other cells. These are among the most common neurodegenerative disorders of childhood, causing seizures, vision loss, cognitive decline, and premature death, requiring extensive supportive care resources.
Documentation Requirements
- ✓Specific NCL type if known (CLN1-CLN14 or infantile, late infantile, juvenile, adult forms)
- ✓Confirmatory diagnostic evidence (genetic testing identifying CLN gene mutations, enzyme assay, or electron microscopy showing curvilinear profiles)
- ✓Current neurological status and functional assessment
- ✓Seizure frequency and anticonvulsant management
- ✓Vision status and ophthalmologic findings
- ✓Documentation of progressive nature and disease trajectory
Commonly Confused Codes
- •E75.29 — Other sphingolipidosis: NCL is NOT a sphingolipidosis; it involves ceroid-lipofuscin, not sphingolipids
- •E75.5 — Other lipid storage disorders: a broader category that should not be used when NCL is specifically diagnosed
- •G31.89 — Other specified degenerative diseases of nervous system: NCL is metabolic, not a primary neurodegenerative code
- •E75.6 — Lipid storage disorder, unspecified: too nonspecific when NCL is confirmed