2026 ICD-10-CM Diagnosis Code E06.1Subacute thyroiditis
ICD-10-CM Codes›E00–E89›E00-E07›E06
- Billable — Valid for Submission
- Not Chronic
E06.1 is a billable ICD-10-CM diagnosis code for subacute 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
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute thyroiditis
- Acute viral thyroiditis
- Atypical subacute thyroiditis
- Infectious thyroiditis
- Mumps thyroiditis
- Subacute granulomatous thyroiditis
- Subacute lymphocytic thyroiditis
- Subacute thyroiditis
- Thyroid infection
- Viral thyroiditis
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- de Quervain thyroiditis
- Giant-cell thyroiditis
- Granulomatous thyroiditis
- Nonsuppurative thyroiditis
- Viral thyroiditis
Type 1 Excludes
- autoimmune thyroiditis E06.3
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Disease, diseased - See Also: Syndrome;
- thyroid - E06.1
- Thyroiditis - E06.9
- de Quervain's - E06.1
- giant-cell (follicular) - E06.1
- granulomatous (de Quervain) (subacute) - E06.1
- nonsuppurative - E06.1
- pseudotuberculous - E06.1
- subacute (granulomatous) - E06.1
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- De Quervain's
- thyroiditis (subacute granulomatous thyroiditis)
- Disease, diseased
- de Quervain's (tendon sheath)
- thyroid (subacute granulomatous thyroiditis)
- Quervain's disease
- thyroid
- Thyroiditis
- de Quervain's
- Thyroiditis
- giant-cell (follicular)
- Thyroiditis
- granulomatous (de Quervain) (subacute)
- Thyroiditis
- nonsuppurative
- Thyroiditis
- pseudotuberculous
- Thyroiditis
- subacute (granulomatous)
- Thyroiditis
- viral
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 E06.1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About E06.1Overview
Is E06.1 (Thyroiditis) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report subacute thyroiditis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does E06.1 group to?
When subacute 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 E06.1?
Under the General Equivalence Mappings, subacute thyroiditis converts to ICD-9-CM 245.1 (subacute thyroiditis). The mapping is a direct match.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
