2026 ICD-10-CM Diagnosis Code E05.01Thyrotoxicosis with diffuse goiter with thyrotoxic crisis or storm

ICD-10-CM Codes›E00–E89›E00-E07›E05

ICD-10-CM E05.01
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E05.01 is a billable ICD-10-CM diagnosis code for thyrotoxicosis with diffuse goiter with thyrotoxic crisis or storm. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 11 through 13, 643 through 645. As a secondary diagnosis, it counts as a major complication or comorbidity (MCC) and places an inpatient stay in the highest severity level of its MS-DRG family. It does not count, however, when the principal diagnosis is one of 59 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Thyroid disorders.

E05.01 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 44 for payment year 2026.

Code Identity

ICD-10-CM Code
E05.01
Billable Status
Yes — Valid for Submission
Code Describes
Thyrotoxicosis with diffuse goiter with thyrotoxic crisis or storm
Short Description
Thyrotoxicosis w diffuse goiter w thyrotoxic crisis or storm
Parent Code
E05.0
Thyrotoxicosis with diffuse goiter

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE00-E07Disorders of thyroid gland
CategoryE05Thyrotoxicosis [hyperthyroidism]
This CodeE05.01Thyrotoxicosis with diffuse goiter with thyrotoxic crisis or storm

Medicare Risk Adjustment (HCC)Billing

E05.01 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
no payment category in the model that pays 100% of MA risk scores
Prior Model (CMS-HCC V24)
Not mapped under V24
this diagnosis newly risk-adjusts under the V28 model
Part D (RxHCC)
RxHCC 44 — Thyroid Disorders
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Graves' disease
  • Graves' disease with acropachy AND with thyrotoxic crisis
  • Graves' disease with pretibial myxedema AND with thyrotoxic crisis
  • Hypertrophic osteoarthropathy
  • Pretibial myxedema
  • Thyroid acropachy
  • Thyroid-associated dermopathy
  • Thyrotoxic crisis
  • Thyrotoxicosis due to Graves' disease
  • Toxic diffuse goiter
  • Toxic diffuse goiter with acropachy
  • Toxic diffuse goiter with crisis
  • Toxic diffuse goiter with pretibial myxedema
  • Toxic diffuse goiter with thyrotoxic crisis

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR END001
Thyroid disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Hyperthyroidism

Hyperthyroidism, or overactive thyroid, happens when your thyroid gland makes more thyroid hormones than your body needs.

The full article covers:

  • What is hyperthyroidism?
  • What causes hyperthyroidism?
  • Who is at risk for hyperthyroidism?
  • What are the symptoms of hyperthyroidism?
  • What other problems can hyperthyroidism cause?
  • How is hyperthyroidism diagnosed?
  • What are the treatments for hyperthyroidism?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert E05.01 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
242.01 Tox dif goiter w crisis
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About E05.01Overview

What is the ICD-10 code for thyrotoxicosis with diffuse goiter with thyrotoxic crisis or storm?

The ICD-10-CM code for thyrotoxicosis with diffuse goiter with thyrotoxic crisis or storm is E05.01 (sometimes written as E0501). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is E05.01 (Thyrotoxicosis with diffuse goiter) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report thyrotoxicosis with diffuse goiter with thyrotoxic crisis or storm on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E05.01 group to?

When thyrotoxicosis with diffuse goiter with thyrotoxic crisis or storm is the principal diagnosis on an inpatient stay, it groups to MS-DRG 11, 12, 13, 643, 644, 645, with relative weights from 0.7683 to 5.4541 depending on complications. Higher weights mean higher Medicare reimbursement.

Is E05.01 a CC or MCC?

CMS lists E05.01 as an MCC (major complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it places the inpatient stay in the highest-weighted DRG of its severity family. It does not count when the principal diagnosis is one of the 59 closely related codes in its exclusion list.

What is the ICD-9 equivalent of E05.01?

Under the General Equivalence Mappings, thyrotoxicosis with diffuse goiter with thyrotoxic crisis or storm converts to ICD-9-CM 242.01 (tox dif goiter w crisis). The mapping is a direct match.

Does E05.01 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage: E05.01 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 44 (Thyroid Disorders).