E76.29
BillableOther mucopolysaccharidoses
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E76.29 an HCC code?
Yes. E76.29 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 E76.29
For E76.29 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 E76.29 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E76.29 is the ICD-10-CM diagnosis code for other mucopolysaccharidoses. Other mucopolysaccharidoses include rare inherited metabolic disorders such as Sly syndrome and Maroteaux-Lamy syndrome, where the body cannot properly break down complex sugars. E76.29 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, E76.29 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, E76.29 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.
Use this code for MPS types IV (other than Morquio), VI, VII, and IX when specifically documented. Because E76.29 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 E76.29 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code for MPS types IV (other than Morquio), VI, VII, and IX when specifically documented
- •Clearly document which specific mucopolysaccharidosis type is being coded to ensure accurate classification
Clinical Significance
Other mucopolysaccharidoses captures MPS types that do not have individual ICD-10-CM codes, including MPS VI (Maroteaux-Lamy), MPS VII (Sly syndrome), and MPS IX (Natowicz syndrome). These are rare but clinically significant lysosomal storage disorders requiring enzyme replacement therapy and multisystem monitoring.
Documentation Requirements
- ✓Specific MPS type documented (e.g., Maroteaux-Lamy/MPS VI, Sly syndrome/MPS VII, Natowicz/MPS IX)
- ✓Confirmatory enzyme assay or genetic testing identifying the specific enzyme deficiency
- ✓Current disease manifestations by organ system
- ✓Treatment status: enzyme replacement therapy (galsulfase for MPS VI), supportive interventions
- ✓Provider statement confirming this is a mucopolysaccharidosis type other than I, II, III, or IV