ICD-10-CM Code E21

Hyperparathyroidism and other disorders of parathyroid gland

Version 2021 Non-Billable Code

Not Valid for Submission

E21 is a "header" nonspecific and non-billable 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 valid for the year 2021 for the submission of HIPAA-covered transactions.

ICD-10:E21
Short Description:Hyperparathyroidism and other disorders of parathyroid gland
Long Description:Hyperparathyroidism and other disorders of parathyroid gland

Consider the following ICD-10 codes with a higher level of specificity:

  • E21.0 - Primary hyperparathyroidism
  • E21.1 - Secondary hyperparathyroidism, not elsewhere classified
  • E21.2 - Other hyperparathyroidism
  • E21.3 - Hyperparathyroidism, unspecified
  • E21.4 - Other specified disorders of parathyroid gland
  • E21.5 - Disorder of parathyroid gland, unspecified

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code E21:

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
  • familial hypocalciuric hypercalcemia E83.52
  • hungry bone syndrome E83.81
  • infantile and juvenile osteomalacia E55.0

Code Classification

  • Endocrine, nutritional and metabolic diseases (E00–E90)
    • Disorders of other endocrine glands (E20-E35)
      • Hyperparathyroidism and other disorders of parathyroid gland (E21)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Information for Patients


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

  • Calcium - ionized (Medical Encyclopedia)
  • Calcium - urine (Medical Encyclopedia)
  • Calcium blood test (Medical Encyclopedia)
  • Hypercalcemia - discharge (Medical Encyclopedia)
  • Hyperparathyroidism (Medical Encyclopedia)
  • Hypoparathyroidism (Medical Encyclopedia)
  • Parathyroid adenoma (Medical Encyclopedia)
  • Parathyroid biopsy (Medical Encyclopedia)
  • Parathyroid cancer (Medical Encyclopedia)
  • Parathyroid gland removal (Medical Encyclopedia)
  • Parathyroid hormone (PTH) blood test (Medical Encyclopedia)

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