2026 ICD-10-CM Diagnosis Code E21Hyperparathyroidism and other disorders of parathyroid gland
E21 is a non-billable ICD-10-CM category code for hyperparathyroidism and other disorders of parathyroid gland, so it cannot be submitted on claims. Use a more specific code from this category instead, such as E21.0, E21.1, E21.2, and E21.3.
Code Identity
Code Classification
Specific Coding for Hyperparathyroidism and other disorders of parathyroid glandOverview
Non-specific codes like E21 require more characters. Use one of these billable codes instead:
Use E21.0 for Primary hyperparathyroidism
Use E21.1 for Secondary hyperparathyroidism, not elsewhere classified
Use E21.2 for Other hyperparathyroidism
Use E21.3 for Hyperparathyroidism, unspecified
Use E21.4 for Other specified disorders of parathyroid gland
Use E21.5 for Disorder of parathyroid gland, unspecified
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Type 1 Excludes
- adult osteomalacia M83
- ectopic hyperparathyroidism E34.2
- hungry bone syndrome E83.81
- infantile and juvenile osteomalacia E55.0
Type 2 Excludes
- familial hypocalciuric hypercalcemia E83.52
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
Patient EducationClinical
Parathyroid Disorders
Most people have four pea-sized glands, called parathyroid glands, on the thyroid gland in the neck. Though their names are similar, the thyroid and parathyroid glands are completely different. The parathyroid glands make parathyroid hormone (PTH), which helps your body keep the right balance of calcium and phosphorous.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Code HistoryHistory
Questions About E21Overview
Is E21 (Hyperparathyroidism and other disorders of parathyroid gland) a billable code?
No. This is a category header that groups the codes for hyperparathyroidism and other disorders of parathyroid gland, and headers cannot be submitted on claims. Claims for hyperparathyroidism and other disorders of parathyroid gland need a more specific code from this category, such as E21.0, E21.1, and E21.2.
