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E21

E21Hyperparathyroidism and other disorders of parathyroid gland

Non-billable headerICD-10-CM

E21 is a non-billable header ICD-10-CM code for hyperparathyroidism and other disorders of parathyroid gland. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

  • adult osteomalacia (M83.-)
  • ectopic hyperparathyroidism (E34.2)
  • hungry bone syndrome (E83.81)
  • infantile and juvenile osteomalacia (E55.0)

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

  • familial hypocalciuric hypercalcemia (E83.52)

Other codes that can never be billed with E21

These codes carry an Excludes1 note pointing at E21. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading E21 alone.

  • M85.6Other cyst of bone
  • N25.81Secondary hyperparathyroidism of renal origin
  • E83Disorders of mineral metabolism
  • E83.5Disorders of calcium metabolism

Risk adjustment

E21 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead E21

6 child codes. Green means billable.

Questions about E21

Is E21 a billable ICD-10-CM code?
No. E21 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does E21 sit in the tabular list?
Endocrine, nutritional and metabolic diseases (E00-E89), in the block Disorders of other endocrine glands (E20-E35).
What cannot be coded together with E21?
E21 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.