E21.2

Billable

Other 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

Elevated parathyroid hormone and calcium levels due to causes other than primary gland disease or secondary causes, or when the specific type is not clearly identified.

Coding Tips

•Use this code when hyperparathyroidism exists but does not fit clearly into primary or secondary categories
•Review documentation to determine if a more specific code (E21.0 or E21.1) would be more appropriate

Clinical Significance

Other hyperparathyroidism captures tertiary hyperparathyroidism and other atypical forms where the parathyroid glands become autonomously overactive, often after prolonged secondary stimulation. Tertiary disease commonly develops in patients with long-standing chronic kidney disease, even after transplant, when glands fail to regress.

Documentation Requirements

✓Document the specific type of hyperparathyroidism (tertiary or other specified form), history of prior secondary hyperparathyroidism, surgical history, calcium and parathyroid hormone levels, and clinical rationale for this classification.

Excludes 1 — Do NOT code together

familial hypocalciuric hypercalcemia (E83.52)

Commonly Confused Codes

E21.0 (primary hyperparathyroidism from de novo gland disease), E21.1 (secondary hyperparathyroidism still responsive to underlying cause treatment), E21.3 (unspecified hyperparathyroidism when documentation is insufficient).

Code Hierarchy

└E21Hyperparathyroidism and other disorders of parathyroid gland └E21.2Other hyperparathyroidism

└E21.2Other hyperparathyroidism