E06.1 Subacute thyroiditis

The ICD-10-CM code for Subacute thyroiditis is E06.1 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

4: Endocrine, nutritional and metabolic diseases (E00-E89)

Section

E00-E07: Disorders of thyroid gland (E00-E07)

Category E06

8 codes (7 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to E06.1:

• Thyroiditis › de Quervain's
• Thyroiditis › pseudotuberculous
• Quervain's disease › thyroid
• De Quervain's › thyroiditis (subacute granulomatous thyroiditis)
• Thyroiditis › nonsuppurative
• Thyroiditis › granulomatous (de Quervain) (subacute)
• Thyroiditis › giant-cell (follicular)
• Thyroiditis › subacute (granulomatous)

Inclusion Terms

• de Quervain thyroiditis
• Giant-cell thyroiditis
• Granulomatous thyroiditis
• Nonsuppurative thyroiditis
• Viral thyroiditis

U.S. Hospital Utilization

• An estimated 440 U.S. inpatient stays in 2023 included E06.1 among the documented diagnoses.
• 105 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Diabetes mellitus (TOC entry)

a. Diabetes mellitus ................................................................................................................... 39

Obesity (TOC entry)

b. Obesity .................................................................................................................................. 42

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)