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E05.20 ICD-10-CM Code: Thyrotoxicosis with toxic multinodular goiter without thyrotoxic crisis or storm

E05.20 is not a CMS-HCC payment code. MEAT criteria · RAF calculator · free HCC coding tools

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FY 2026 Apr update / Endocrine, nutritional and metabolic diseases (E00-E89) / Disorders of thyroid gland (E00-E07)

E05.20

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

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.

Buddy the Bee presenting code insight

Buddy Insight

Thyrotoxicosis with toxic multinodular goiter without thyrotoxic crisis or storm represents autonomous thyroid hormone production from multiple hyperfunctioning nodules within a multinodular goiter.

CMS-HCC V28

N/A

Not mapped

CMS-HCC V24

N/A

Not mapped

ACA/HHS

N/A

Not mapped

ESRD/PACE

N/A

Not mapped

RXHCC

HCC 44

RAF 0.070

Code Book Path

Official
E05Thyrotoxicosis [hyperthyroidism]
E05.2Thyrotoxicosis with toxic multinodular goiter
E05.20Thyrotoxicosis with toxic multinodular goiter without thyrotoxic crisis or storm

Inclusion Terms

Official
  • Toxic nodular goiter NOS

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for E05.20 in this effective period.

Related Child Codes

Official
E05.21Thyrotoxicosis with toxic multinodular goiter with thyrotoxic crisis or storm

Includes

Official

ICD-10-CM does not list Includes notes for E05.20 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for E05.20 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for E05.20 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for E05.20 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for E05.20 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance
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.

MEAT Support

HCC Buddy guidance
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.

Audit Caution

HCC Buddy guidance
Ensure thyroid function tests confirm thyrotoxicosis; do not assign for multinodular goiter with normal thyroid function (use E04.2). Confirm that multiple nodules are present, not a single dominant toxic nodule (which would be E05.10). If thyroid storm develops, transition to E05.
Screen for and document atrial fibrillation, which frequently accompanies this condition in older patients and requires separate coding (I48.-).

Common Mistakes

HCC Buddy guidance
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.

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is E05.20 an HCC code?

E05.20 is not in the CMS-HCC V28 or V24 community payment model, but it does map to Thyroid and Parathyroid Disorders under the Part D RxHCC model.

Code
E05.20
Description
Thyrotoxicosis with toxic multinodular goiter without thyrotoxic crisis or storm
HCC (V28)
No CMS-HCC V28 mapping
RAF
Billable
Yes
Payment year
2026

HCC Category Mapping

RxHCCHCC 44, Thyroid and Parathyroid Disorders
0.070

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. 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.

Work E05.20 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for E05.20

For E05.20 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 E05.20 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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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 a CMS-HCC V28 payment category. Capture depends on documentation that supports the diagnosis; verify the HCC assignment against the current CMS mapping for the applicable payment year. Coders reviewing E05.20 should check whether additional documentation would support a more specific child code in the same hierarchy that does map to a payment HCC, capturing the correct specificity is the highest-impact RAF improvement available within accurate coding.

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.

Child Codes

Code Hierarchy

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