ICD-10 Code E05.21 – Thyrotoxicosis with toxic multinodular goiter with thyrotoxic crisis or storm (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E05.21 – Thyrotoxicosis with toxic multinodular goiter with thyrotoxic crisis or storm
What it is
This code identifies severe thyrotoxicosis caused by a toxic multinodular goiter, with a thyroid storm or crisis. Use it when the record shows both multinodular goiter-related hyperthyroidism and an acute life-threatening exacerbation.
Clinical signs
Clinical features vary; refer to documentation. Typical findings include marked hyperthyroid symptoms with acute systemic decompensation, such as agitation, fever, tachycardia, or altered mental status, consistent with thyroid storm.
When to use this code
Use this code when the provider documents toxic multinodular goiter and explicitly states thyrotoxic crisis, thyroid storm, or equivalent wording. It also fits inpatient or emergency records describing acute decompensation from known toxic multinodular goiter. Check documentation if the storm component is not clearly stated.
Do not use for
Do not use this code for uncomplicated toxic multinodular goiter without crisis, or for other causes of thyrotoxicosis. If the record only says hyperthyroidism or goiter, confirm the exact diagnosis before coding.
Coding tip
Code E05.21 only when both the toxic multinodular goiter and the thyrotoxic crisis are documented together.