E05.20
BillableThyrotoxicosis with toxic multinodular goiter without thyrotoxic crisis or storm
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E05.20 an HCC code?
No. E05.20 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 E05.20
For E05.20to 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 E05.20 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E05.20 is the ICD-10-CM diagnosis code for thyrotoxicosis with toxic multinodular goiter without thyrotoxic crisis or storm. This condition occurs when an overactive thyroid gland with multiple nodules produces excessive thyroid hormones, causing symptoms like rapid heartbeat, weight loss, and anxiety, but without a life-threatening thyroid storm. The patient's thyroid is overworking due to multiple growths rather than a single nodule. E05.20 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).
E05.20 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). While the thyrotoxicosis itself does not carry community model RAF, associated conditions like atrial fibrillation may carry their own HCC mappings.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E05.20 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify documentation specifies 'multinodular goiter' and confirms the absence of thyrotoxic crisis or storm before assigning this code; if crisis/storm is present, use E05.21 instead
- •This code includes both the thyrotoxicosis and the multinodular goiter etiology, so do not code them separately; ensure the provider has documented the toxic multinodular goiter as the cause
Clinical Significance
Thyrotoxicosis with toxic multinodular goiter without thyrotoxic crisis or storm represents autonomous thyroid hormone production from multiple hyperfunctioning nodules within a multinodular goiter. This condition typically develops in older adults with longstanding multinodular goiter and presents with more gradual onset of hyperthyroidism compared to Graves disease. Cardiac complications including atrial fibrillation are particularly common in this population due to the typical advanced age at presentation.
Documentation Requirements
- ✓Documentation should confirm multinodular goiter with thyrotoxicosis, supported by thyroid function tests (suppressed thyroid-stimulating hormone, elevated free thyroxine), imaging showing multiple nodules with heterogeneous uptake on thyroid scan, and clinical findings.
- ✓The absence of thyrotoxic crisis must be established.
- ✓Treatment plan (radioactive iodine, surgery, antithyroid medications) and cardiovascular assessment (particularly for atrial fibrillation) should be documented.
Commonly Confused Codes
- •E04.2 (Nontoxic multinodular goiter) captures multinodular goiter without hyperthyroidism.
- •E05.21 (Thyrotoxicosis with toxic multinodular goiter WITH crisis) captures the crisis form.
- •E05.00 (Thyrotoxicosis with diffuse goiter) captures Graves disease.
- •E05.10 (Thyrotoxicosis with toxic single thyroid nodule) captures a single toxic nodule rather than multiple nodules.