ICD-10 Code E21 – Hyperparathyroidism and other disorders of parathyroid gland (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E21 – Hyperparathyroidism and other disorders of parathyroid gland
What it is
E21 covers disorders of the parathyroid glands, including hyperparathyroidism. These conditions affect parathyroid hormone regulation and can disrupt calcium balance.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include abnormal calcium-related symptoms, kidney stones, bone disease, or parathyroid enlargement noted on evaluation.
When to use this code
Use E21 when the provider documents hyperparathyroidism or another parathyroid gland disorder without a more specific code. It is also appropriate when the record identifies parathyroid dysfunction, but the exact subtype is not further specified. Code from the documented diagnosis, not from suspected laboratory abnormalities alone.
Do not use for
Do not use E21 for postoperative hypoparathyroidism or other clearly different parathyroid conditions. Check documentation if the chart only mentions abnormal calcium or an uncertain endocrine finding.
Coding tip
Look for the exact parathyroid diagnosis and any specified subtype before assigning the code.