E21.3 Hyperparathyroidism, unspecified

The ICD-10-CM code for Hyperparathyroidism, unspecified is E21.3 (FY2026). It is a billable, claim-ready diagnosis code.

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

Also Known As

ICD-10-CM Alphabetic Index entries that lead to E21.3:

• Hyperparathyroidism
• Hyperfunction › parathyroid (gland)
• Arthritis, arthritic (acute) (chronic) (nonpyogenic) (subacute) › in (due to) › hyperparathyroidism NEC
• Myopathy › in (due to) › hyperparathyroidism NEC
• Arthropathy › hemophilic NEC › in (due to) › hyperparathyroidism NEC

U.S. Hospital Utilization

• An estimated 58,530 U.S. inpatient stays in 2023 included E21.3 among the documented diagnoses.
• 575 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Diabetes mellitus (TOC entry)

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

Obesity (TOC entry)

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

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

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)

Cite This Page

Reference E21.3 with the canonical source and edition:

E21.3 — Hyperparathyroidism, unspecified. ICD-10 Coding Pro (ICD-10-CM FY2026). https://icd10codingpro.com/codes/E21.3

Canonical URL: https://icd10codingpro.com/codes/E21.3