ICD-10 Code E06.2 – Chronic thyroiditis with transient thyrotoxicosis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E06.2 – Chronic thyroiditis with transient thyrotoxicosis
What it is
E06.2 identifies chronic thyroiditis, usually autoimmune, with a temporary hyperthyroid phase. The thyroid is inflamed, and hormone leakage can cause brief thyrotoxicosis before thyroid function changes again.
Clinical signs
Clinical features vary; refer to documentation. You may see a history of chronic thyroid inflammation plus transient symptoms of thyrotoxicosis, such as palpitations, tremor, heat intolerance, or weight loss.
When to use this code
Use this code when the provider documents chronic thyroiditis with a temporary thyrotoxic phase, including cases consistent with Hashimoto-related thyroiditis. Code it only when both the chronic thyroiditis and transient thyrotoxicosis are stated or clearly linked.
Do not assume it from nonspecific thyroid dysfunction alone. If the record only says thyroiditis, hyperthyroidism, or thyrotoxicosis without the chronic thyroiditis link, check documentation.
Do not use for
Do not use E06.2 for Graves disease, isolated thyrotoxicosis, or thyroiditis without a transient thyrotoxic phase. Check documentation when the cause of hyperthyroidism is not clearly chronic thyroiditis.
Coding tip
Assign E06.2 only when the transient thyrotoxicosis is explicitly associated with chronic thyroiditis in the provider record.