E21: Hyperparathyroidism and other disorders of parathyroid gland
Codes under E21 (Hyperparathyroidism and other disorders of parathyroid gland). A ✓ marks a billable (fully specified) code; category codes without a ✓ are not billable on their own.
| Code | Description | Billable |
|---|---|---|
| E21.0 | Primary hyperparathyroidism | ✓ |
| E21.0 | Primary hyperparathyroidism | ✓ |
| E21.1 | Secondary hyperparathyroidism, not elsewhere classified | ✓ |
| E21.1 | Secondary hyperparathyroidism, not elsewhere classified | ✓ |
| E21.2 | Other hyperparathyroidism | ✓ |
| E21.2 | Other hyperparathyroidism | ✓ |
| E21.3 | Hyperparathyroidism, unspecified | ✓ |
| E21.3 | Hyperparathyroidism, unspecified | ✓ |
| E21.4 | Other specified disorders of parathyroid gland | ✓ |
| E21.4 | Other specified disorders of parathyroid gland | ✓ |
| E21.5 | Disorder of parathyroid gland, unspecified | ✓ |
| E21.5 | Disorder of parathyroid gland, unspecified | ✓ |
Frequently asked questions
What is ICD-10-CM code E21?
E21 is an ICD-10-CM category covering Hyperparathyroidism and other disorders of parathyroid gland. It contains 12 more specific diagnosis codes, 12 of which are billable.
Is E21 a billable code?
No — E21 is a category header and isn't billable on its own. Code to the highest level of specificity using one of its subcodes (for example E21.0 — Primary hyperparathyroidism). 12 of the 12 codes under E21 are billable.
What codes fall under E21?
E21 includes E21.0, E21.0, E21.1, E21.1, E21.2, plus 7 more. See the full list with descriptions and billable status above.
More free billing tools: all ICD-10 categories · ICD-10 search · denial codes · Medicare fees
Informational only, not coding or medical advice. Verify against the official ICD-10-CM (FY2026) and your payer's guidelines.
Code the diagnosis right
Join providers across the country delivering modern virtual care with CareNiva. Free to start, ready in minutes.
100% Satisfaction Guaranteed — try it risk-free