E31.20
BillableMultiple endocrine neoplasia [MEN] syndrome, unspecified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E31.20 an HCC code?
Yes. E31.20 maps to Other Significant Endocrine and Metabolic 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 E31.20
For E31.20 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 E31.20 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E31.20 is the ICD-10-CM diagnosis code for multiple endocrine neoplasia [men] syndrome, unspecified. A hereditary condition where multiple hormone-producing glands develop tumors, but the specific type is not specified. E31.20 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering disorders of other endocrine glands (e20-e35).
Under the CMS-HCC V28 risk adjustment model, E31.20 maps to Other Significant Endocrine and Metabolic Disorders (HCC 51) with a community, non-dual, aged base RAF weight of 0.233. Under the older V24 model, E31.20 mapped to the same category but with a base RAF weight of 0.230 — V28 recalibrated weights across the entire model. 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 only when the type of MEN syndrome cannot be determined from documentation. Because E31.20 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 E31.20 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when the type of MEN syndrome cannot be determined from documentation
- •Query the provider if additional testing or clinical findings suggest MEN type I or IIB for more specific coding
Clinical Significance
Multiple endocrine neoplasia syndrome unspecified indicates a hereditary cancer predisposition syndrome where tumors develop in multiple endocrine glands, but the specific type has not been determined. The three main types (I, IIA, IIB) have different tumor profiles, inheritance patterns, and management strategies, making type identification essential.
Documentation Requirements
- ✓Query the provider for the specific multiple endocrine neoplasia type.
- ✓Document family history of endocrine tumors, genetic testing results (MEN1 gene for Type I, RET proto-oncogene for Types IIA/IIB), which glands are affected, and tumor surveillance plan.