ICD-10 Code E20.0 – Idiopathic hypoparathyroidism (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E20.0 – Idiopathic hypoparathyroidism
What it is
E20.0 identifies hypoparathyroidism with no known cause. It means the parathyroid glands are underactive, but documentation does not support surgery, radiation, genetic, or other specific causes.
Clinical signs
Typical findings include symptoms of low calcium such as muscle cramps, tingling, tetany, or seizures. Clinical features vary; refer to documentation, and confirm that the condition is described as idiopathic.
When to use this code
Use E20.0 when the record clearly states idiopathic hypoparathyroidism or hypoparathyroidism of unknown cause. It is appropriate when the clinician documents hypoparathyroidism and does not identify a secondary cause. Check documentation if the cause is postoperative, autoimmune, genetic, or otherwise specified.
Do not use for
Do not use this code for postoperative hypoparathyroidism, pseudohypoparathyroidism, or hypocalcemia without documented hypoparathyroidism. If another etiology is named, code the documented condition instead.
Coding tip
Confirm that “idiopathic” refers to the hypoparathyroidism itself, not to calcium abnormalities alone.