E76.210
BillableMorquio A mucopolysaccharidoses
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E76.210 an HCC code?
Yes. E76.210 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 E76.210
For E76.210 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 E76.210 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E76.210 is the ICD-10-CM diagnosis code for morquio a mucopolysaccharidoses. Morquio A mucopolysaccharidosis is a rare inherited metabolic disorder characterized by severe skeletal deformities, short stature, and progressive joint and spine problems due to accumulation of complex sugars. E76.210 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, E76.210 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, E76.210 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.
Morquio A is the classic form; ensure you are not confusing it with Morquio B, which has different enzyme deficiency. Because E76.210 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 E76.210 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Morquio A is the classic form; ensure you are not confusing it with Morquio B, which has different enzyme deficiency
- •Document associated complications such as cardiac valve disease, hearing loss, or vision problems for comprehensive coding
Clinical Significance
Morquio A mucopolysaccharidosis (MPS IVA) is caused by deficiency of N-acetylgalactosamine-6-sulfatase (GALNS), leading to accumulation of keratan sulfate and chondroitin-6-sulfate. It primarily affects the skeleton with severe short stature, spinal cord compression risk, and joint laxity while preserving intelligence, making it distinct from many other MPS types.
Documentation Requirements
- ✓Specific diagnosis of Morquio A syndrome (MPS IVA) documented
- ✓Confirmatory enzyme assay showing GALNS deficiency or genetic testing with GALNS gene mutation
- ✓Skeletal manifestations: short trunk dwarfism, pectus carinatum, genu valgum, odontoid hypoplasia
- ✓Cervical spine stability assessment (risk of atlantoaxial subluxation/spinal cord compression)
- ✓Treatment plan including enzyme replacement therapy (elosulfase alfa/Vimizim), surgical interventions, or supportive care
Commonly Confused Codes
- •E76.211 — Morquio B (MPS IVB): different enzyme deficiency (beta-galactosidase), same skeletal phenotype
- •E76.219 — Morquio, unspecified: use only when A vs. B subtype is not documented
- •E76.1 — Hunter syndrome (MPS II): has skeletal features but also hepatosplenomegaly and potential neurodegeneration
- •Q77.4 — Achondroplasia: skeletal dysplasia that may mimic Morquio radiographically but is a different entity
- •E76.22 — Sanfilippo syndrome (MPS III): primarily neurological, not skeletal