E05.11
BillableThyrotoxicosis with toxic single thyroid nodule with thyrotoxic crisis or storm
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E05.11 an HCC code?
No. E05.11 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 E05.11
For E05.11to 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 E05.11 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E05.11 is the ICD-10-CM diagnosis code for thyrotoxicosis with toxic single thyroid nodule with thyrotoxic crisis or storm. This condition occurs when a single nodule (lump) in the thyroid gland produces excessive thyroid hormone, causing a severe and life-threatening emergency state called thyroid storm. Thyroid storm involves dangerously high body temperature, rapid heart rate, and other critical symptoms requiring immediate medical intervention. E05.11 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering disorders of thyroid gland (e00-e07).
E05.11 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.
This code does not map to any HCC under V24 or V28, providing no community risk adjustment impact. It maps to RxHCC 44 (Osteoporosis, Vertebral and Pathological Fractures). Despite the acute life-threatening nature of thyroid storm, this code does not carry community model risk adjustment weight.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E05.11 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code includes the crisis/storm component, so do not assign a separate code for thyroid storm; the crisis is inherent to this code
- •Verify documentation confirms both the toxic single nodule AND the acute thyrotoxic crisis/storm before assigning this code; if crisis is not present, use E05.10 instead
Clinical Significance
Thyrotoxicosis with toxic single thyroid nodule with thyrotoxic crisis or storm is a rare but life-threatening presentation where a single autonomously functioning thyroid nodule causes thyroid storm. This presentation is less common than thyroid storm from Graves disease but carries equally serious mortality risk. Clinical features include extreme hyperthermia, cardiovascular collapse, altered mental status, and multiorgan dysfunction requiring immediate intensive care management.
Documentation Requirements
- ✓Documentation must establish both the toxic single thyroid nodule etiology and the presence of thyrotoxic crisis meeting clinical criteria (Burch-Wartofsky Point Scale).
- ✓Thyroid function tests, imaging confirming a single hyperfunctioning nodule, clinical severity findings, precipitating factors, and intensive care treatment should be documented.
- ✓The crisis presentation must be clearly distinguished from uncomplicated toxic nodule thyrotoxicosis.
Commonly Confused Codes
- •E05.10 (Thyrotoxicosis with toxic single thyroid nodule WITHOUT crisis) captures the stable form.
- •E05.01 (Thyrotoxicosis with diffuse goiter with crisis) captures thyroid storm from Graves disease.
- •E05.21 (Thyrotoxicosis with toxic multinodular goiter with crisis) captures storm from multinodular disease.
- •E05.91 (Thyrotoxicosis, unspecified with crisis) is less specific regarding the etiology.