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ICD-10-CM 2027 diagnosis code

K31.A0Gastric intestinal metaplasia, unspecified

✓ Billable / specific

K31.A0 is a valid, billable ICD-10-CM code for gastric intestinal metaplasia, unspecified. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Gastric intestinal metaplasia.

Code last changed in FY2022 (effective October 1, 2021). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About K31.A0

K31.A0 is the ICD-10-CM diagnosis code for gastric intestinal metaplasia, unspecified. It belongs to category K31 (other diseases of stomach and duodenum), block K20-K31 (diseases of esophagus, stomach and duodenum) and chapter 11 (diseases of the digestive system). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within K31.A, choose K31.A0 (unspecified) only when documentation doesn't support a more specific option: without dysplasia (K31.A1) and with dysplasia (K31.A2).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 391 (Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders with MCC, relative weight 1.2392) and DRG 392 (Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders without MCC, relative weight 0.7645), in MDC 06 (Diseases and Disorders of the Digestive System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It was added in FY2022, effective October 1, 2021.

Coding notes

Applicable toConditions and synonyms classified to this code
  • Gastric intestinal metaplasia indefinite for dysplasia
  • Gastric intestinal metaplasia NOS

Notes that apply from higher levels

Instructions written at a parent level also apply to K31.A0.

› From K31 Other diseases of stomach and duodenum
Includes
  • functional disorders of stomach
Excludes2

Broader instructions also apply from K20-K31 Diseases of esophagus, stomach and duodenum and Chapter 11: Diseases of the digestive system.

Alphabetic index entries

2 entries

Terms in the official ICD-10-CM index that lead to K31.A0.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2022 (effective 10/1/2021): Added
  • No changes since FY2022.

Common questions about K31.A0

Is K31.A0 billable?

Yes. K31.A0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can K31.A0 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict K31.A0 as a principal diagnosis.

Is K31.A0 a CC or MCC?

No. K31.A0 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does K31.A0 group to?

K31.A0 is used in the MS-DRG v44.0 logic for MS-DRG 391 (Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders with MCC) and MS-DRG 392 (Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders without MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.