ICD-10 Code E06.3 – Autoimmune thyroiditis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E06.3 – Autoimmune thyroiditis
What it is
E06.3 identifies autoimmune thyroiditis, a condition where the immune system attacks the thyroid gland. It is commonly used for chronic lymphocytic thyroiditis, including Hashimoto thyroiditis.
Clinical signs
Clinical features vary; refer to documentation. Common findings include thyroid enlargement, hypothyroid symptoms, and positive thyroid autoantibodies when documented.
When to use this code
Use E06.3 when the record clearly documents autoimmune thyroiditis or Hashimoto thyroiditis as the diagnosis. It also fits encounters focused on evaluation or follow-up of this autoimmune thyroid disorder. If the note only says thyroid disorder without confirmation, check documentation.
Do not use for
Do not use this code for nonautoimmune thyroiditis or unspecified thyroid dysfunction. If the provider documents a different thyroid condition, code that diagnosis instead.
Coding tip
Code E06.3 only when the autoimmune nature is stated or clearly supported by the record.