ICD-10 Code E06.1 – Subacute thyroiditis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E06.1 – Subacute thyroiditis
What it is
E06.1 identifies subacute thyroiditis, an inflammatory thyroid disorder that is usually temporary and often follows a viral illness. It causes thyroid pain or tenderness with changes in thyroid function.
Clinical signs
Typical findings include a painful, enlarged, tender thyroid and possible neck pain that may radiate to the jaw or ears. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents subacute thyroiditis, including painful de Quervain-type thyroiditis. It also fits confirmed cases described as viral or granulomatous thyroiditis when the record supports the same diagnosis. Check documentation if the note only says thyroid pain.
Do not use for
Do not use E06.1 for chronic thyroiditis, autoimmune hypothyroidism, or unspecified thyroid inflammation without a clear subacute diagnosis. If the documentation is unclear, code the stated condition or check documentation.
Coding tip
Code E06.1 only when the record explicitly supports subacute thyroiditis, not just abnormal thyroid tests or nonspecific neck pain.