E04.0
BillableNontoxic diffuse goiter
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E04.0 an HCC code?
No. E04.0 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 E04.0
For E04.0to 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 E04.0 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E04.0 is the ICD-10-CM diagnosis code for nontoxic diffuse goiter. An enlarged thyroid gland that is spread throughout the entire gland but is not producing excess thyroid hormone. E04.0 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).
E04.0 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). Coding value is primarily clinical, supporting documentation of thyroid pathology and potential surgical planning for compressive goiters.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E04.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm the goiter is nontoxic (not causing hyperthyroidism); if toxic features are present, use E05 codes instead
- •Document whether the patient has symptoms of compression (difficulty swallowing, breathing) as this affects management
Clinical Significance
Nontoxic diffuse goiter represents enlargement of the entire thyroid gland without associated thyrotoxicosis or hypothyroidism (euthyroid state). Common causes include physiologic goiter during puberty or pregnancy, autoimmune thyroiditis without functional change, and sporadic goiter of unknown etiology. While often benign, large goiters can cause compressive symptoms including dysphagia, dyspnea, and stridor, potentially requiring surgical intervention.
Documentation Requirements
- ✓Documentation should confirm diffuse thyroid enlargement with normal thyroid function (euthyroid status).
- ✓Thyroid function tests demonstrating normal thyroid-stimulating hormone and free thyroxine levels, thyroid ultrasound findings showing diffuse enlargement without suspicious nodules, and assessment for compressive symptoms should be recorded.
- ✓The non-toxic (euthyroid) nature must be established to distinguish from toxic goiter.
Commonly Confused Codes
- •E01.0 (Iodine-deficiency related diffuse goiter) requires an iodine-deficiency etiology.
- •E05.00 (Thyrotoxicosis with diffuse goiter without crisis) captures Graves disease with hyperthyroidism.
- •E06.3 (Autoimmune thyroiditis) may cause diffuse goiter but identifies a specific autoimmune etiology.
- •E04.1 (Nontoxic single thyroid nodule) and E04.2 (Nontoxic multinodular goiter) capture nodular rather than diffuse patterns.