2026 ICD-10-CM Diagnosis Code E06.2Chronic thyroiditis with transient thyrotoxicosis

ICD-10-CM Codes›E00–E89›E00-E07›E06

ICD-10-CM E06.2
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E06.2 is a billable ICD-10-CM diagnosis code for chronic thyroiditis with transient thyrotoxicosis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 643 through 645. Coders also document this condition as chronic thyroiditis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Thyroid disorders.

Code Identity

ICD-10-CM Code
E06.2
Billable Status
Yes — Valid for Submission
Code Describes
Chronic thyroiditis with transient thyrotoxicosis
Short Description
Chronic thyroiditis with transient thyrotoxicosis
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 CodeE06.2Chronic thyroiditis with transient thyrotoxicosis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Chronic thyroiditis
  • Chronic thyroiditis with transient thyrotoxicosis

Tabular List NotesGuidance

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

Type 1 Excludes

  • autoimmune thyroiditis E06.3

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Thyroiditis
      • chronic (nonspecific) (sclerosing)
        • with thyrotoxicosis, transient
    • Thyrotoxicosis(recurrent)
      • transient with chronic thyroiditis

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

  • Hashimoto Disease

    chronic autoimmune thyroiditis, characterized by the presence of high serum thyroid autoantibodies; goiter; and hypothyroidism.

  • Postpartum Thyroiditis

    transient autoimmune thyroiditis occurring in the postpartum period. it is characterized by the presence of high titers of autoantibodies against thyroid peroxidase and thyroglobulin. clinical signs include the triphasic thyroid hormone pattern: beginning with thyrotoxicosis, followed with hypothyroidism, then return to euthyroid state by 1 year postpartum.

  • Thyroiditis

    inflammatory diseases of the thyroid gland. thyroiditis can be classified into acute (thyroiditis, suppurative), subacute (granulomatous and lymphocytic), chronic fibrous (riedel's), chronic lymphocytic (hashimoto disease), transient (postpartum thyroiditis), and other autoimmune thyroiditis subtypes.

  • Thyroiditis, Autoimmune

    inflammatory disease of the thyroid gland due to autoimmune responses leading to lymphocytic infiltration of the gland. it is characterized by the presence of circulating thyroid antigen-specific t-cells and thyroid autoantibodies. the clinical signs can range from hypothyroidism to thyrotoxicosis depending on the type of autoimmune thyroiditis.

  • Thyroiditis, Subacute

    spontaneously remitting inflammatory condition of the thyroid gland, characterized by fever; muscle weakness; sore throat; severe thyroid pain; and an enlarged damaged gland containing giant cells. the disease frequently follows a viral infection.

  • Thyroiditis, Suppurative

    acute inflammatory disease of the thyroid gland due to infections by bacteria; fungi; or other microorganisms. symptoms include tender swelling, fever, and often with leukocytosis.

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 E06.2 to ICD-9-CMHistory

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

ICD-9-CM
245.8 Chr thyroiditis NEC/NOS
Approximate The match is approximate rather than exact.

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 E06.2Overview

Is E06.2 (Thyroiditis) a billable code?

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

What MS-DRG does E06.2 group to?

When chronic thyroiditis with transient thyrotoxicosis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 643, 644, 645, with relative weights from 0.7683 to 1.6461 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of E06.2?

Under the General Equivalence Mappings, chronic thyroiditis with transient thyrotoxicosis converts to ICD-9-CM 245.8 (chr thyroiditis NEC/NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.