2026 ICD-10-CM Diagnosis Code E16.4Increased secretion of gastrin

ICD-10-CM Codes›E00–E89›E15-E16›E16

ICD-10-CM E16.4
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E16.4 is a billable ICD-10-CM diagnosis code for increased secretion of gastrin. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 380 through 382. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified endocrine disorders.

Code Identity

ICD-10-CM Code
E16.4
Billable Status
Yes — Valid for Submission
Code Describes
Increased secretion of gastrin
Short Description
Increased secretion of gastrin
Same as the full description in the CMS dataset.
Parent Code
E16
Other disorders of pancreatic internal secretion

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE15-E16Other disorders of glucose regulation and pancreatic internal secretion
CategoryE16Other disorders of pancreatic internal secretion
This CodeE16.4Increased secretion of gastrin

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormal hormone secretion
  • Abnormality of secretion of gastrin
  • Anastomotic ulcer due to Zollinger-Ellison syndrome
  • Cancerous ulcer
  • Drug-induced hypergastrinemia
  • Duodenal ulcer due to Zollinger-Ellison syndrome
  • Familial hypergastrinemic duodenal ulcer
  • Gastric ulcer due to Zollinger-Ellison syndrome
  • Gastrinoma
  • Hyperplasia of islet alpha cells with gastrin excess
  • Impaired acid inhibition of gastrin release
  • Increased gastrin secretion
  • Islet cell hyperplasia
  • Megaloblastic anemia due to Zollinger-Ellison syndrome
  • Zollinger-Ellison syndrome

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Hypergastrinemia
  • Hyperplasia of pancreatic endocrine cells with gastrin excess
  • Zollinger-Ellison syndrome

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Abnormal, abnormality, abnormalities
      • gastrin secretion
    • Abnormal, abnormality, abnormalities
      • secretion
        • gastrin
    • Ellison-Zollinger syndrome
    • Hypergastrinemia
    • Hyperplasia, hyperplastic
      • pancreatic islet cells
        • alpha
          • with excess
            • gastrin
    • Hypersecretion
      • gastrin
    • Increase, increased
      • secretion
        • gastrin
    • Zollinger-Ellison syndrome

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR END015
Other specified and unspecified endocrine disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Gastrinoma

    a gastrin-secreting neuroendocrine tumor of the non-beta islet cells, the gastrin-secreting cells. this type of tumor is primarily located in the pancreas or the duodenum. majority of gastrinomas are malignant. they metastasize to the liver; lymph nodes; and bone but rarely elsewhere. the presence of gastrinoma is one of three requirements to be met for identification of zollinger-ellison syndrome, which sometimes occurs in families with multiple endocrine neoplasia type 1; (men 1).

Patient EducationClinical

Pancreatic Diseases

The pancreas is a gland behind your stomach and in front of your spine. It produces juices that help break down food and hormones that help control blood sugar levels. Problems with the pancreas can lead to many health problems. These include:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert E16.4 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
251.5 Abnorm secretion gastrin
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About E16.4Overview

Is E16.4 (Other disorders of pancreatic internal secretion) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report increased secretion of gastrin on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does E16.4 group to?

When increased secretion of gastrin is the principal diagnosis on an inpatient stay, it groups to MS-DRG 380, 381, 382, with relative weights from 0.8006 to 1.9622 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of E16.4?

Under the General Equivalence Mappings, increased secretion of gastrin converts to ICD-9-CM 251.5 (abnorm secretion gastrin). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.