E21.0

Billable

Primary hyperparathyroidism

HCC Category Mapping

V24HCC 23 — Other Significant Endocrine and Metabolic Disorders

0.230

ESRDHCC 23 — Other Significant Endocrine and Metabolic Disorders

0.000

RxHCCHCC 43 — Other Significant Endocrine and Metabolic Disorders

0.000

What This Code Means

Overactivity of the parathyroid glands due to an intrinsic problem with the glands themselves, causing elevated calcium levels in the blood.

Coding Tips

•Ensure the hyperparathyroidism is primary (gland dysfunction) and not secondary to kidney disease or vitamin D deficiency
•Document whether adenoma, hyperplasia, or carcinoma is present if known

Clinical Significance

Primary hyperparathyroidism results from autonomous overproduction of parathyroid hormone, most commonly due to a parathyroid adenoma, leading to hypercalcemia with serious skeletal, renal, and cardiovascular consequences. Left untreated, chronic hypercalcemia accelerates osteoporosis, nephrolithiasis, and increases cardiovascular mortality risk.

Documentation Requirements

✓Document the underlying etiology (adenoma, hyperplasia, or carcinoma), serum calcium and parathyroid hormone levels, presence of end-organ damage (kidney stones, bone density loss), and current treatment plan including surgical status.

Commonly Confused Codes

E21.1 (secondary hyperparathyroidism due to another condition like chronic kidney disease), E21.3 (hyperparathyroidism unspecified when type is not determined), E83.52 (hypercalcemia which is a lab finding, not the underlying disorder).

Code Hierarchy

└E21Hyperparathyroidism and other disorders of parathyroid gland └E21.0Primary hyperparathyroidism

└E21.0Primary hyperparathyroidism