2026 ICD-10-CM Diagnosis Code E06.3Autoimmune thyroiditis

ICD-10-CM Codes›E00–E89›E00-E07›E06

ICD-10-CM E06.3
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E06.3 is a billable ICD-10-CM diagnosis code for autoimmune thyroiditis. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Thyroid disorders.

Code Identity

ICD-10-CM Code
E06.3
Billable Status
Yes — Valid for Submission
Code Describes
Autoimmune thyroiditis
Short Description
Autoimmune 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 CodeE06.3Autoimmune thyroiditis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Atrophic Hashimoto thyroiditis
  • Atrophy of thyroid - acquired
  • Autoimmune hypothyroidism
  • Autoimmune thyroiditis
  • Chronic thyroiditis
  • Dementia due to autoimmune encephalitis
  • Dementia due to Hashimoto encephalopathy
  • Fibrous autoimmune thyroiditis
  • Goiter due to thyroiditis
  • Goitrous Hashimoto thyroiditis
  • Hashimoto thyroiditis
  • Hashitoxicosis - transient
  • Hyperthyroidism with Hashimoto disease
  • Hypothyroidism due to Hashimoto's thyroiditis
  • Immunoglobulin G4 related disease
  • Immunoglobulin G4 related thyroid disease
  • Primary hypothyroidism
  • Restrictive ophthalmopathy
  • Steroid-responsive encephalopathy associated with autoimmune thyroiditis
  • Subacute autoimmune thyroiditis
  • Subacute thyroiditis
  • Thyroid atrophy
  • Thyroid degeneration
  • Thyroid eye disease

Tabular List NotesGuidance

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

Inclusion Terms

  • Hashimoto's thyroiditis
  • Hashitoxicosis (transient)
  • Lymphadenoid goiter
  • Lymphocytic thyroiditis
  • Struma lymphomatosa

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.

    • Autoimmune
      • thyroiditis
    • Disease, diseased
      • autoimmune (systemic) NOS
        • thyroid
    • Disease, diseased
      • Hashimoto's (struma lymphomatosa)
    • Goiter(plunging) (substernal)
      • lymphadenoid
    • Hashimoto's disease or thyroiditis
    • Hashitoxicosis(transient)
    • Lymphadenoid goiter
    • Struma
      • Hashimoto
    • Struma
      • lymphomatosa
    • Thyroiditis
      • autoimmune
    • Thyroiditis
      • chronic (nonspecific) (sclerosing)
        • lymphadenoid
    • Thyroiditis
      • chronic (nonspecific) (sclerosing)
        • lymphocytic
    • Thyroiditis
      • chronic (nonspecific) (sclerosing)
        • lymphoid
    • Thyroiditis
      • Hashimoto's (struma lymphomatosa)
    • Thyroiditis
      • lymphocytic (chronic)
    • Thyroiditis
      • lymphoid
    • Thyroiditis
      • lymphomatous

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

  • Iatrogenic Primary Hypothyroidism

    primary hypothyroidism due to medical or surgical treatment.

  • Primary Hypothyroidism

    abnormally low levels of thyroid hormones due to a disorder originating within the thyroid gland.

  • Transient Primary Hypothyroidism

    primary hypothyroidism that resolves spontaneously.

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 E06.3 to ICD-9-CMHistory

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

ICD-9-CM
245.2 Chr lymphocyt thyroidit
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 E06.3Overview

Is E06.3 (Thyroiditis) a billable code?

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

What MS-DRG does E06.3 group to?

When autoimmune thyroiditis 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 E06.3?

Under the General Equivalence Mappings, autoimmune thyroiditis converts to ICD-9-CM 245.2 (chr lymphocyt thyroidit). The mapping is a direct match.

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.