K31.A12 ICD-10-CM Code: Gastric intestinal metaplasia without dysplasia, involving the body (corpus)
Compare with another codeCheck this code on a claim
Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.
Coding at a Glance
- Tabular directives
- 1 inclusion term · 3 Excludes2
Billable · FY2027A valid, specific ICD-10-CM code, reportable for dates of service in FY2027.
What you need to know
Source: CMS/NCHS Official ICD-10-CM tabular notes, quoted. From the CMS/NCHS tabular list for the release in force. A note the category or block publishes applies to this code too; the Instructions section marks which is which.
- Excludes2Not included here; may be reported together
- IncludesWhat this code covers
- functional disorders of stomach
Most relevant related codes MedCoder-derived
Read off the official notes above and this code’s own position in the tabular list. Which to report is a documentation question; Compare shows the two side by side.
Inpatient Payment Groups (MS-DRG)
Potential MS-DRG participation — not a DRG assignment.
MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v44, Appendix B.
- MS-DRG 391 — ESOPHAGITIS, GASTROENTERITIS AND MISCELLANEOUS DIGESTIVE DISORDERS WITH MCC (MDC 06)
- MS-DRG 392 — ESOPHAGITIS, GASTROENTERITIS AND MISCELLANEOUS DIGESTIVE DISORDERS WITHOUT MCC (MDC 06)
A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.
Coding instructions
Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for K31.A12 in the official ICD-10-CM tabular list, quoted as published.
Source: CMS/CDC — ICD-10-CM Tabular ListRelease: FY2027Effective: October 1, 2026
Trace:FY2027 changesChange historyRelease, file and checksum
Notes without a marker are published on K31.A12 itself; “inherited from” names the category or block whose note applies here.
Includes
Conditions the official ICD-10-CM tabular list includes under this code.
- functional disorders of stomach
Source: inherited from K31
Excludes2 — Not Included Here
Conditions not covered by this code, but which may be reported alongside it when both are present.
- diabetic gastroparesis (E08.43, E09.43, E10.43, E11.43, E13.43) inherited from K31Compare K31.A12 vs E08.43 →
- diverticulum of duodenum (K57.00-K57.13) inherited from K31Compare K31.A12 vs K57.00 →
- hiatus hernia (K44.-) inherited from K20-K31Compare K31.A12 vs K44 →
Coder workflow for K31.A12
MedCoder structured workflow — derived from this code’s own official record
Documentation check
- The provider’s diagnostic statement
- Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
- Anatomical site
- At the most specific level the record states; a site the classification separates cannot be assumed from a procedure or a measurement.
- The associated condition or complication
- Whether the associated condition the title names is documented; the “with” convention presumes some links, and a provider statement that the conditions are unrelated defeats it (Guidelines I.A.15).
Official instructions as workflow
Excludes2 — not part of K31.A12(3 notes)
Coding workflow: The conditions named in this note are not included in K31.A12. When the record documents both, both may be reported; the note is a boundary, not a prohibition.
CompareE08.43, E09.43, E10.43, E11.43, E13.43, K44
See the official tabular notes · Guidelines I.A.12.b
Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.
Coding context
Guidelines, coding notes, decision aids, relationships (with MS-DRG and CCSR classification), hierarchy, HCC, coverage and the context map: what a coder reaches for after the core. Each section names whether it is official source data, a MedCoder-derived relationship or MedCoder editorial.
Code Overview
MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.
Official Coding Guidelines
No excerpt in the ICD-10-CM Official Guidelines names this code specifically. Its chapter carries only this chapter-wide note:
Chapter 11: Diseases of the Digestive System (K00-K95)
Reserved for future guideline expansion
Verify Before Coding
- No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.
From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.
Relationships & Classification
MedCoder-derived relationships — computed from published CMS and AHRQ datasets
Other codes that name K31.A12 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.
Referenced by 1 Excludes2 note: K59 — Other functional intestinal disorders (via K31.-).
These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.
MS-DRG Grouper Relationships (FY2027)
Potential MS-DRG participation — not a DRG assignment.
FY2027 MS-DRG: not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity for that release.
Named in the grouper logic of 2 MS-DRGs: DRG 391 (MDC 06), DRG 392 (MDC 06).
From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.
Clinical classification (AHRQ CCSR):DIG008 — Other specified and unspecified disorders of stomach and duodenum (default).
Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.
Related Codes
Same clinical category (CCSR)
AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Other specified and unspecified disorders of stomach and duodenum).
K31.3 — Pylorospasm, not elsewhere classified, K31.4 — Gastric diverticulum, K31.6 — Fistula of stomach and duodenum, K31.7 — Polyp of stomach and duodenum, K31.811 — Angiodysplasia of stomach and duodenum with bleeding, K31.819 — Angiodysplasia of stomach and duodenum without bleeding, K31.82 — Dieulafoy lesion (hemorrhagic) of stomach and duodenum, K31.83 — Achlorhydria, K31.84 — Gastroparesis, K31.89 — Other diseases of stomach and duodenum, K31.9 — Disease of stomach and duodenum, unspecified, K31.A0 — Gastric intestinal metaplasia, unspecified, K31.A11 — Gastric intestinal metaplasia without dysplasia, involving the antrum, K31.A13 — Gastric intestinal metaplasia without dysplasia, involving the fundus, K31.A14 — Gastric intestinal metaplasia without dysplasia, involving the cardia, K31.A15 — Gastric intestinal metaplasia without dysplasia, involving multiple sites, K31.A19 — Gastric intestinal metaplasia without dysplasia, unspecified site, K31.A21 — Gastric intestinal metaplasia with low grade dysplasia, K31.A22 — Gastric intestinal metaplasia with high grade dysplasia, K31.A29 — Gastric intestinal metaplasia with dysplasia, unspecified, +4 more
Same Index main term, other category
The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Metaplasia”; these codes share that main term but sit in a different category of the Tabular List.
D73.1 — Hypersplenism (spleen), K22.7 — Barrett's esophagus (esophagus), N28.89 — Other specified disorders of kidney and ureter (kidney), N32.89 — Other specified disorders of bladder (squamous cell, bladder), N85.8 — Other specified noninflammatory disorders of uterus (endometrium)
Lab tests where this diagnosis supports Medicare coverage (NCD)
Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.
Contextual Map
Every relationship of K31.A12 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.
Run K31.A12 with this related code in Claim Check
Hierarchy
- K00-K95 — Chapter 11: Diseases of the Digestive System (K00-K95) (K00-K95)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- K20-K31 — Diseases of esophagus, stomach and duodenum[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
Referenced by Excludes2 notes
- K59 — Other functional intestinal disorders[Excludes2](via K31.-): “functional disorders of stomach (K31.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2027
Clinical classification (CCSR)
- DIG008 — Other specified and unspecified disorders of stomach and duodenum[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
MS-DRG Grouper
- DRG 391 — ESOPHAGITIS, GASTROENTERITIS AND MISCELLANEOUS DIGESTIVE DISORDERS WITH MCC[MS-DRG]: “ESOPHAGITIS, GASTROENTERITIS AND MISCELLANEOUS DIGESTIVE DISORDERS WITH MCC (MDC 06)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
- DRG 392 — ESOPHAGITIS, GASTROENTERITIS AND MISCELLANEOUS DIGESTIVE DISORDERS WITHOUT MCC[MS-DRG]: “ESOPHAGITIS, GASTROENTERITIS AND MISCELLANEOUS DIGESTIVE DISORDERS WITHOUT MCC (MDC 06)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2027
MDC crossing
- MDC 06 — Diseases and Disorders of the Digestive System[MDC crossing]: “Diseases and Disorders of the Digestive System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 5,748 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2027
Index entries
- Metaplasia, gastric intestinal, without dysplasia, involving, body (corpus)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027
Nearest codes (31)
- K31 — Other diseases of stomach and duodenum[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- K31.0 — Acute dilatation of stomach[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- K31.1 — Adult hypertrophic pyloric stenosis[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- K31.2 — Hourglass stricture and stenosis of stomach[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- K31.3 — Pylorospasm, not elsewhere classified[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- K31.4 — Gastric diverticulum[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- K31.5 — Obstruction of duodenum[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- K31.6 — Fistula of stomach and duodenum[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2027
- and 23 more
Change history
- FY2022 — Added to the code set[Change history]— CMS release files (code change ledger) · icd10cm-fy2022
Reference
Index terms and tables, published questions and FAQ, every source behind this page with its release and checksum, the date-of-service check and the complete change history.
Indexed Clinical Terms (1)
Official source data — entries quoted as published, in the Index’s own lookup phrasing
Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.
Sources for this page
Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.
- Code, title, tabular notes and index terms Official source data
- CMS/CDC ICD-10-CM FY2027 tabular list, index and tables, effective October 1, 2026 Release, file and checksum · Publisher’s page
- Coding guidelines Official source data
- ICD-10-CM Official Guidelines for Coding and Reporting (FY2027), quoted by section Release, file and checksum · Publisher’s page
- Claim edits Official source data
- CMS Definitions of Medicare Code Edits — v44.0 (October 2026) Release, file and checksum · Publisher’s page
- Inpatient payment groups Official source data
- CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v44 Release, file and checksum · Publisher’s page
- Change history and date-of-service validity Official source data
- CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
- Comparisons, relationships and the contextual map MedCoder-derived relationship
- Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
- Summary and FAQ answers MedCoder editorial explanation
- Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.
Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources
Labels on this page: Official source data · MedCoder-derived relationship · MedCoder editorial explanation. How to read the labels · All data sources and release dates · CMS coding rules
Cite this page
Reference this page in a research guide, syllabus or article. The release is included because code content changes each year.
MedCoder.ai. "K31.A12 — Gastric intestinal metaplasia without dysplasia, involving the body (corpus)." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/k31.a12-gastric-intestinal-metaplasia-without-dysplasia-involving-the-body-corpus
Change history
- FY2022 — October 1, 2021Added to the code setGastric intestinal metaplasia without dysplasia, involving the body (corpus)FY2022 changes
Nearest Codes in This Family
Official ICD-10-CM classifications closest to K31.A12 in its code family, with their registry titles.
- K31.9 — Disease of stomach and duodenum, unspecified
- K31.A — Gastric intestinal metaplasia
- K31.A0 — Gastric intestinal metaplasia, unspecified
- K31.A1 — Gastric intestinal metaplasia without dysplasia
- K31.A11 — Gastric intestinal metaplasia without dysplasia, involving the antrum
- K31.A13 — Gastric intestinal metaplasia without dysplasia, involving the fundus
- K31.A14 — Gastric intestinal metaplasia without dysplasia, involving the cardia
- K31.A15 — Gastric intestinal metaplasia without dysplasia, involving multiple sites
- K31.A19 — Gastric intestinal metaplasia without dysplasia, unspecified site
- K31.A2 — Gastric intestinal metaplasia with dysplasia