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  6. 2024 ICD-10-CM Code E21
Version 2024
Non-Billable Code

2024 ICD-10-CM Diagnosis Code E21

Hyperparathyroidism and other disorders of parathyroid gland

ICD-10-CM Code:
E21
ICD-10 Code for:
Hyperparathyroidism and other disorders of parathyroid gland
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

  • Endocrine, nutritional and metabolic diseases
    (E00–E89)
    • Disorders of other endocrine glands
      (E20-E35)
      • Hyperparathyroidism and other disorders of parathyroid gland
        (E21)

E21 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of hyperparathyroidism and other disorders of parathyroid gland. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding Applicable to Hyperparathyroidism and other disorders of parathyroid gland

Non-specific codes like E21 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for hyperparathyroidism and other disorders of parathyroid gland:

  • Use E21.0 for Primary hyperparathyroidism - BILLABLE CODE

  • Use E21.1 for Secondary hyperparathyroidism, not elsewhere classified - BILLABLE CODE

  • Use E21.2 for Other hyperparathyroidism - BILLABLE CODE

  • Use E21.3 for Hyperparathyroidism, unspecified - BILLABLE CODE

  • Use E21.4 for Other specified disorders of parathyroid gland - BILLABLE CODE

  • Use E21.5 for Disorder of parathyroid gland, unspecified - BILLABLE CODE

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Type 1 Excludes

Type 1 Excludes
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.
  • adult osteomalacia M83
  • ectopic hyperparathyroidism E34.2
  • hungry bone syndrome E83.81
  • infantile and juvenile osteomalacia E55.0

Type 2 Excludes

Type 2 Excludes
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.
  • familial hypocalciuric hypercalcemia E83.52

Patient Education


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.

If your parathyroid glands make too much or too little hormone, it disrupts this balance. If they secrete extra PTH, you have hyperparathyroidism, and your blood calcium rises. In many cases, a benign tumor on a parathyroid gland makes it overactive. Or, the extra hormones can come from enlarged parathyroid glands. Very rarely, the cause is cancer.

If you do not have enough PTH, you have hypoparathyroidism. Your blood will have too little calcium and too much phosphorous. Causes include injury to the glands, endocrine disorders, or genetic conditions. Treatment is aimed at restoring the balance of calcium and phosphorous.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.