2026 ICD-10-CM Diagnosis Code E06.0Acute thyroiditis

ICD-10-CM Codes›E00–E89›E00-E07›E06

ICD-10-CM E06.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E06.0 is a billable ICD-10-CM diagnosis code for acute thyroiditis. 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 complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 7 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Thyroid disorders.

E06.0 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
E06.0
Billable Status
Yes — Valid for Submission
Code Describes
Acute thyroiditis
Short Description
Acute thyroiditis
Same as the full description in the CMS dataset.
Parent Code
E06
Thyroiditis

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE00-E07Disorders of thyroid gland
CategoryE06Thyroiditis
This CodeE06.0Acute thyroiditis

Medicare Risk Adjustment (HCC)Billing

E06.0 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.

  • Abscess of thyroid
  • Acute bacterial thyroiditis
  • Acute fungal thyroiditis
  • Acute non-suppurative thyroiditis
  • Acute suppurative thyroiditis
  • Acute thyroiditis
  • Infectious thyroiditis
  • Thyroid infection
  • Thyrotoxicosis due to acute thyroiditis

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Abscess of thyroid
  • Pyogenic thyroiditis
  • Suppurative thyroiditis

Use Additional Code

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

Clinical InformationClinical

  • Acute Suppurative Thyroiditis

    thyroiditis due to a bacterial infection.

Patient EducationClinical

Thyroid Diseases

Your thyroid is a small, butterfly-shaped gland in the front of your neck. It makes hormones that control the way the body uses energy. These hormones affect nearly every organ in your body and control many of your body's most important functions. For example, they affect your breathing, heart rate, weight, digestion, and moods.

Read the full article at MedlinePlus

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

Convert E06.0 to ICD-9-CMHistory

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

ICD-9-CM
245.0 Acute thyroiditis
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 E06.0Overview

What is the ICD-10 code for acute thyroiditis?

The ICD-10-CM code for acute thyroiditis is E06.0 (sometimes written as E060). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is E06.0 (Thyroiditis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report acute thyroiditis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E06.0 group to?

When acute thyroiditis 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 E06.0 a CC or MCC?

CMS lists E06.0 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 7 closely related codes in its exclusion list.

What is the ICD-9 equivalent of E06.0?

Under the General Equivalence Mappings, acute thyroiditis converts to ICD-9-CM 245.0 (acute thyroiditis). The mapping is a direct match.

Does E06.0 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage: E06.0 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 44 (Thyroid Disorders).