2026 ICD-10-CM Diagnosis Code K31Other diseases of stomach and duodenum

ICD-10-CM Codes›K00–K95›K20-K31›K31

ICD-10-CM K31
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K31 is a non-billable ICD-10-CM category code for other diseases of stomach and duodenum, so it cannot be submitted on claims. Use a more specific code from this category instead, such as K31.0, K31.1, K31.2, and K31.3.

Code Identity

ICD-10-CM Code
K31
Billable Status
No — Non-Billable Category
Code Describes
Other diseases of stomach and duodenum
Chapter
K20-K31
Diseases of esophagus, stomach and duodenum

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK20-K31Diseases of esophagus, stomach and duodenum
CategoryK31Other diseases of stomach and duodenum
This CodeK31Other diseases of stomach and duodenum

Specific Coding for Other diseases of stomach and duodenumOverview

Non-specific codes like K31 require more characters. Use one of these billable codes instead:

  • Use K31.0 for Acute dilatation of stomach

  • Use K31.1 for Adult hypertrophic pyloric stenosis

  • Use K31.2 for Hourglass stricture and stenosis of stomach

  • Use K31.3 for Pylorospasm, not elsewhere classified

  • Use K31.4 for Gastric diverticulum

  • Use K31.5 for Obstruction of duodenum

  • Use K31.6 for Fistula of stomach and duodenum

  • Use K31.7 for Polyp of stomach and duodenum

  • K31.8 for Other specified diseases of stomach and duodenum

  • K31.81 for Angiodysplasia of stomach and duodenum

  • Use K31.82 for Dieulafoy lesion (hemorrhagic) of stomach and duodenum

  • Use K31.83 for Achlorhydria

  • Use K31.84 for Gastroparesis

  • Use K31.89 for Other diseases of stomach and duodenum

  • Use K31.9 for Disease of stomach and duodenum, unspecified

  • K31.A for Gastric intestinal metaplasia

  • Use K31.A0 for Gastric intestinal metaplasia, unspecified

  • K31.A1 for Gastric intestinal metaplasia without dysplasia

  • K31.A2 for Gastric intestinal metaplasia with dysplasia

Tabular List NotesGuidance

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

Includes

  • functional disorders of stomach

Type 2 Excludes

Patient EducationClinical

Stomach Disorders

Your stomach is an organ between your esophagus and small intestine. It is where digestion of protein begins. The stomach has three tasks. It stores swallowed food. It mixes the food with stomach acids. Then it sends the mixture on to the small intestine.

Read the full article at MedlinePlus

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

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 K31Overview

Is K31 (Other diseases of stomach and duodenum) a billable code?

No. This is a category header that groups the codes for other diseases of stomach and duodenum, and headers cannot be submitted on claims. Claims for other diseases of stomach and duodenum need a more specific code from this category, such as K31.0, K31.1, and K31.2.