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K55.029 ICD-10-CM Code: Acute infarction of small intestine, extent unspecified

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 Excludes1 · 1 Excludes2
Risk adjustment
CMS-HCC V22 category 107

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.

Excludes1Never report with this code
  • necrotizing enterocolitis of newborn (P77.-)
Excludes2Not included here; may be reported together
  • angioectasia (angiodysplasia) duodenum (K31.81-)

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.

CompareCheck ClaimView Related Codes

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 393 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITH MCC (MDC 06)
  • MS-DRG 394 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITH CC (MDC 06)
  • MS-DRG 395 — OTHER DIGESTIVE SYSTEM DIAGNOSES WITHOUT CC/MCC (MDC 06)
  • MS-DRG 791 — PREMATURITY WITH MAJOR PROBLEMS (MDC 15)
  • MS-DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)

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 K55.029 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 K55.029 itself; “inherited from” names the category or block whose note applies here.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Source: inherited from K55

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Source: inherited from K55

Coder workflow for K55.029

MedCoder structured workflow — derived from this code’s own official record

Before you code K55.029

  1. Unspecified does not mean incorrect. When the record gives no greater specificity, K55.029 may be the appropriate code. Check the record for detail that supports a more specific sibling — in this subcategory the siblings differ by acute versus chronic. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

    ReviewK55.021, K55.022

    See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

  2. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with K55.029. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the record document the detail a more specific sibling code needs?
    Yes → Review the specific siblings in this subcategory.
    No → Continue — K55.029 is appropriate when the documentation goes no further.

    ReviewK55.021, K55.022

  2. Does the documentation support a condition named in K55.029’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewP77

Consider K55.029. Then confirm the code is valid for the date of service in the Verify section.

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).
Acuity
Acute or chronic as documented; when both are documented and separate codes exist, both are reported with the acute code first (Guidelines I.B.8).
Any detail beyond this code’s title
What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

  • Excludes1 — check before selecting K55.029(1 note)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with K55.029: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareP77

    See the official tabular notes · Guidelines I.A.12.a

  • Excludes2 — not part of K55.029(1 note)

    Coding workflow: The conditions named in this note are not included in K55.029. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

    CompareK31.81

    See the official tabular notes · Guidelines I.A.12.b

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: The provider documents the condition in the terms of this code’s title and records no further detail.

Coding question: Is a more specific sibling code supportable?

Path: Review the specific siblings in this subcategory and what each requires the record to state.

Reason: A more specific code needs documentation of the distinguishing element; without it the unspecified code is appropriate, and a provider query is the route to specificity (Guidelines I.A.9.b, I.B.18).

ReviewK55.021, K55.022

Documentation: Both the condition K55.029 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewP77

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.

Don’t confuse K55.029 with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of K55.029 — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

  • P77— Excludes1 conflict (Excludes1 — generally not reported together)

    Not coded here — the tabular list excludes this pair for the same encounter.

    Not reported together with this code, except where the two conditions are documented as unrelated.

    What moves you there: Documentation of necrotizing enterocolitis of newborn moves the case to P77; the two are not reported together unless documented as unrelated.

    Full comparison: K55.029 vs P77 →

  • K31.81— Excludes2 relationship (Informational)

    Distinct conditions — both may be reported.

    A distinct condition — both may be reported when both are documented.

    What moves you there: Documentation of angioectasia (angiodysplasia) duodenum adds K31.81; it is not part of this code and both may be reported when both are documented.

    Full comparison: K55.029 vs K31.81 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

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

Acute infarction of small intestine, extent unspecified is a billable ICD-10-CM diagnosis code (K55.029).

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

  • MCC as a secondary diagnosis (FY2027). Can raise the stay's MS-DRG severity tier.

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 K55.029 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 2 Excludes2 notes: I74 — Arterial embolism and thrombosis (via K55.0.-), I82 — Other venous embolism and thrombosis (via K55.0.-).

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: MCC — Major Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 23 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 5 MS-DRGs: DRG 393 (MDC 06), DRG 394 (MDC 06), DRG 395 (MDC 06), DRG 791 (MDC 15), DRG 793 (MDC 15).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):DIG025 — Other specified and unspecified gastrointestinal disorders (default); CIR026 — Peripheral and visceral vascular disease.

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 process (MS-DRG)

Acts as MCC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

K55.011 — Focal (segmental) acute (reversible) ischemia of small intestine, K55.012 — Diffuse acute (reversible) ischemia of small intestine, K55.019 — Acute (reversible) ischemia of small intestine, extent unspecified, K55.021 — Focal (segmental) acute infarction of small intestine, K55.022 — Diffuse acute infarction of small intestine, K55.031 — Focal (segmental) acute (reversible) ischemia of large intestine, K55.032 — Diffuse acute (reversible) ischemia of large intestine, K55.039 — Acute (reversible) ischemia of large intestine, extent unspecified, K55.041 — Focal (segmental) acute infarction of large intestine, K55.042 — Diffuse acute infarction of large intestine, K55.049 — Acute infarction of large intestine, extent unspecified, K55.051 — Focal (segmental) acute (reversible) ischemia of intestine, part unspecified, K55.052 — Diffuse acute (reversible) ischemia of intestine, part unspecified, K55.059 — Acute (reversible) ischemia of intestine, part and extent unspecified, K55.061 — Focal (segmental) acute infarction of intestine, part unspecified, K55.062 — Diffuse acute infarction of intestine, part unspecified, K55.069 — Acute infarction of intestine, part and extent unspecified, K55.1 — Chronic vascular disorders of intestine, K55.30 — Necrotizing enterocolitis, unspecified, K55.31 — Stage 1 necrotizing enterocolitis, +2 more

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Other specified and unspecified gastrointestinal disorders, Peripheral and visceral vascular disease).

I73.1 — Thromboangiitis obliterans [Buerger's disease], I73.81 — Erythromelalgia, I73.89 — Other specified peripheral vascular diseases, I73.9 — Peripheral vascular disease, unspecified, K55.0 — Acute vascular disorders of intestine, K55.011 — Focal (segmental) acute (reversible) ischemia of small intestine, K55.012 — Diffuse acute (reversible) ischemia of small intestine, K55.019 — Acute (reversible) ischemia of small intestine, extent unspecified, K55.021 — Focal (segmental) acute infarction of small intestine, K55.022 — Diffuse acute infarction of small intestine, K55.031 — Focal (segmental) acute (reversible) ischemia of large intestine, K55.032 — Diffuse acute (reversible) ischemia of large intestine, K55.039 — Acute (reversible) ischemia of large intestine, extent unspecified, K55.041 — Focal (segmental) acute infarction of large intestine, K55.042 — Diffuse acute infarction of large intestine, K55.049 — Acute infarction of large intestine, extent unspecified, K55.051 — Focal (segmental) acute (reversible) ischemia of intestine, part unspecified, K55.052 — Diffuse acute (reversible) ischemia of intestine, part unspecified, K55.059 — Acute (reversible) ischemia of intestine, part and extent unspecified, K55.061 — Focal (segmental) acute infarction of intestine, part unspecified, +318 more

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main terms “Thrombosis, thrombotic”, “Infarct, infarction”; these codes share that main term but sit in a different category of the Tabular List.

I82.C2 — Chronic embolism and thrombosis of internal jugular vein (vein, internal jugular, chronic), I89.8 — Other specified noninfective disorders of lymphatic vessels and lymph nodes (lymph node), I97.190 — Other postprocedural cardiac functional disturbances following cardiac surgery (myocardium, myocardial, postprocedural, following cardiac surgery), I97.191 — Other postprocedural cardiac functional disturbances following other surgery (myocardium, myocardial, postprocedural, following other surgery), I97.790 — Other intraoperative cardiac functional disturbances during cardiac surgery (myocardium, myocardial, intraoperative, during cardiac surgery), I97.791 — Other intraoperative cardiac functional disturbances during other surgery (myocardium, myocardial, intraoperative, during other surgery), I97.810 — Intraoperative cerebrovascular infarction during cardiac surgery (cerebral, intraoperative, during cardiac surgery), I97.811 — Intraoperative cerebrovascular infarction during other surgery (cerebral, intraoperative, during other surgery), I97.820 — Postprocedural cerebrovascular infarction following cardiac surgery (cerebral, postprocedural, following cardiac surgery), I97.821 — Postprocedural cerebrovascular infarction following other surgery (cerebral, postprocedural, following other surgery), K64.5 — Perianal venous thrombosis (anal), K76.3 — Infarction of liver (liver), K82.8 — Other specified diseases of gallbladder (gallbladder), K86.89 — Other specified diseases of pancreas (pancreas), M62.20 — Nontraumatic ischemic infarction of muscle, unspecified site (muscle), M62.21 — Nontraumatic ischemic infarction of muscle, shoulder (muscle, shoulder region), M62.22 — Nontraumatic ischemic infarction of muscle, upper arm (muscle, upper arm), M62.23 — Nontraumatic ischemic infarction of muscle, forearm (muscle, forearm), M62.24 — Nontraumatic ischemic infarction of muscle, hand (muscle, hand), M62.25 — Nontraumatic ischemic infarction of muscle, thigh (muscle, thigh), +134 more

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.

Fecal Occult Blood Test (FOBT), Gamma-glutamyl Transferase (GGT) Test, Iron Panel, Partial Thromboplastin Time (PTT) Test, Prothrombin Time Test and INR (PT/INR)

Contextual Map

Every relationship of K55.029 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 K55.029 with these 2 related codes in Claim Check

Hierarchy

Referenced by Excludes2 notes

Clinical classification (CCSR)

MS-DRG Grouper

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
  • MDC 15 — Newborns and Other Neonates with Conditions Originating in Perinatal Period[MDC crossing]: “Newborns and Other Neonates with Conditions Originating in Perinatal Period — 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.”— CMS MS-DRG Definitions Manual · FY2027

Index entries

  • Infarct, infarction, intestine (acute) (agnogenic) (embolic) (hemorrhagic) (nonocclusive) (nonthrombotic) (occlusive) (thrombotic) (with gangrene), small[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2027

Nearest codes (36)

Change history

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. "K55.029 — Acute infarction of small intestine, extent unspecified." ICD-10-CM FY2027. https://medcoder.ai/icd10/code/k55.029-acute-infarction-of-small-intestine-extent-unspecified

Change history

  • FY2017 — October 1, 2016
    Added to the code set
    Acute infarction of small intestine, extent unspecified
    FY2017 changes

Nearest Codes in This Family

Official ICD-10-CM classifications closest to K55.029 in its code family, with their registry titles.

View all codes in the K55 family