What does ICD-10 code E21 mean?

E21 is the ICD-10-CM diagnosis code for Hyperparathyroidism and other disorders of parathyroid gland. Hyperparathyroidism and other disorders of parathyroid gland

Is E21 a billable ICD-10 code?

No, E21 is not a billable code. You may need to select a more specific code from this category.

What chapter is E21 in?

E21 is classified under Chapter 4: Endocrine, nutritional and metabolic diseases (E00-E89), Section E20-E35: Disorders of other endocrine glands (E20-E35).

What are the includes and excludes for E21?

Excludes1 (not coded here): adult osteomalacia (M83.-); ectopic hyperparathyroidism (E34.2); hungry bone syndrome (E83.81). Excludes2 (not included here): familial hypocalciuric hypercalcemia (E83.52).

What more specific codes exist under E21?

More specific codes under E21 include: E21.0, E21.1, E21.2, E21.3, E21.4. Select the most specific code that matches the clinical documentation.

E21 Hyperparathyroidism and other disorders of parathyroid gland

⚠ Non-Billable ICD-10-CM 2026

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The ICD-10-CM code for Hyperparathyroidism and other disorders of parathyroid gland is E21 (FY2026). It is a non-billable category code — select a more specific code below for claims.

Classification

Chapter: 4: Endocrine, nutritional and metabolic diseases (E00-E89)
Section: E20-E35: Disorders of other endocrine glands (E20-E35)
Category E21: 7 codes (6 billable)
FY2026 Status: Stable since FY2024

Excludes1

Not coded here. These conditions should NOT be coded together with E21.

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

Excludes2

Not included here. These conditions are coded elsewhere but may be coded together if applicable.

familial hypocalciuric hypercalcemia (E83.52)

Official Coding Guidelines

Diabetes mellitus (TOC entry)

a. Diabetes mellitus ................................................................................................................... 39

— ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.4.a

Obesity (TOC entry)

b. Obesity .................................................................................................................................. 42

— ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.4.b

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

E21 Hyperparathyroidism and other disorders of parathyroid gland

Classification

Official Coding Guidelines

References

Related Codes

More Specific Codes

Related Codes in E21

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