E16.9 Disorder of pancreatic internal secretion, unspecified

The ICD-10-CM code for Disorder of pancreatic internal secretion, unspecified is E16.9 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

4: Endocrine, nutritional and metabolic diseases (E00-E89)

Section

E15-E16: Other disorders of glucose regulation and pancreatic internal secretion (E15-E16)

Category E16

12 codes (10 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to E16.9:

• Disorder (of) › pancreatic internal secretion
• Hyperplasia, hyperplastic › pancreatic islet cells
• Increase, increased › secretion › pancreas, endocrine

Inclusion Terms

• Islet-cell hyperplasia NOS
• Pancreatic endocrine cell hyperplasia NOS

U.S. Hospital Utilization

• An estimated 130 U.S. inpatient stays in 2023 included E16.9 among the documented diagnoses.

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)