2026 ICD-10-CM Diagnosis Code K31.A11Gastric intestinal metaplasia without dysplasia, involving the antrum

ICD-10-CM Codes›K00–K95›K20-K31›K31

ICD-10-CM K31.A11
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K31.A11 is a billable ICD-10-CM diagnosis code for gastric intestinal metaplasia without dysplasia, involving the antrum. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 391 through 392. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified disorders of stomach and duodenum.

Code Identity

ICD-10-CM Code
K31.A11
Billable Status
Yes — Valid for Submission
Code Describes
Gastric intestinal metaplasia without dysplasia, involving the antrum
Short Description
Gastric intestnl metaplasia without dysplasia, w the antrum
Parent Code
K31.A1
Gastric intestinal metaplasia without dysplasia

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK20-K31Diseases of esophagus, stomach and duodenum
CategoryK31Other diseases of stomach and duodenum
This CodeK31.A11Gastric intestinal metaplasia without dysplasia, involving the antrum

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR DIG008
Other specified and unspecified disorders of stomach and duodenum
Default principal diagnosis: inpatient Yes · outpatient Yes

Code History & ChangesHistory

Replacement K31.A11 replaces the following previously assigned code(s):

  • K31.89 - Other diseases of stomach and duodenum
FY 2022AddedAdded to the ICD-10-CM code setEffective October 1, 2021.
FY 2023–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About K31.A11Overview

What is the ICD-10 code for gastric intestinal metaplasia without dysplasia, involving the antrum?

The ICD-10-CM code for gastric intestinal metaplasia without dysplasia, involving the antrum is K31.A11 (sometimes written as K31A11). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is K31.A11 (Gastric intestinal metaplasia without dysplasia) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report gastric intestinal metaplasia without dysplasia, involving the antrum on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does K31.A11 group to?

When gastric intestinal metaplasia without dysplasia, involving the antrum is the principal diagnosis on an inpatient stay, it groups to MS-DRG 391, 392, with relative weights from 0.7796 to 1.2683 depending on complications. Higher weights mean higher Medicare reimbursement.