K57.80 ICD-10-CM Code: Diverticulitis of intestine, part unspecified, with perforation and abscess without bleeding

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for K57.80 in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on K57.80 itself; “inherited from” names the category or block whose note applies here.

This page already reflects the FY2027 tabular notes taking effect October 1, 2026.

Coder workflow for K57.80

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

Before you code K57.80

1. Unspecified does not mean incorrect. When the record gives no greater specificity, K57.80 may be the appropriate code. Check the record for detail that supports a more specific sibling — in this subcategory the siblings differ by the presence or absence of the associated condition. 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).

   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 K57.80. 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 — K57.80 is appropriate when the documentation goes no further.
2. Does the documentation support a condition named in K57.80’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.

   ReviewQ43.8, Q43.0

Consider K57.80. Then review the Code Also note, and 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).

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).

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 K57.80(2 notes)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with K57.80: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareQ43.8, Q43.0

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

• Excludes2 — not part of K57.80(1 note)

  Coding workflow: The conditions named in this note are not included in K57.80. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareK38.2

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

• Code Also — related condition(3 notes)

  Coding workflow: Review the related condition when both are documented and the instruction applies. A Code Also note does not fix sequencing; the order follows the circumstances of the encounter.

  ReviewK6A.0, K65

  See the official tabular notes · Guidelines I.A.17

Coding decision scenarios

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

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.

Indexed Clinical Terms (5)

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.

• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic), with, diverticular disease (intestine)
• Diverticulitis (acute), intestine, with, abscess, perforation
• Perforation, perforated (nontraumatic) (of), diverticulum (intestine)
• Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion), with or following, diverticular disease (intestine)
• Rupture, ruptured, diverticulum (intestine)

Official Coding Guidelines

No excerpt in the ICD-10-CM Official Guidelines names this code specifically. Its chapter carries only this chapter-wide note:

Don’t confuse K57.80 with…

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

The codes most likely to be picked instead of K57.80 — 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.

• Q43.8— Excludes1 conflict (Conflict)

  Not coded here — these two are mutually exclusive.

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

  What moves you there: Documentation of congenital diverticulum of intestine moves the case to Q43.8; the two are not reported together unless documented as unrelated.

  Full comparison: K57.80 vs Q43.8 →

• Q43.0— Excludes1 conflict (Conflict)

  Not coded here — these two are mutually exclusive.

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

  What moves you there: Documentation of Meckel's diverticulum moves the case to Q43.0; the two are not reported together unless documented as unrelated.

  Full comparison: K57.80 vs Q43.0 →

• K38.2— 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 diverticulum of appendix adds K38.2; it is not part of this code and both may be reported when both are documented.

  Full comparison: K57.80 vs K38.2 →

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.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

1. 3 Code Also notes — a second code may apply; the guidelines leave its sequencing to the circumstances of the encounter. See the Code Also notes
2. 2 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes
3. 1 Excludes2 entry — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

• CC as a secondary diagnosis (FY2026). 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 structured relationships — computed from published CMS and AHRQ datasets

Other codes that name K57.80 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 Excludes1 note: K92.2 — Gastrointestinal hemorrhage, unspecified (via K57.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 2 Code Also instructions: K65 — Peritonitis (via K57.-), K6A.0 — Pelvic abscess (via K57.-).

These codes suggest coding this condition alongside when both are present.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

CC — 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 18 clinically related codes on its CMS exclusion list.

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):DIG013 — Diverticulosis and diverticulitis (default); DIG006 — Gastrointestinal and biliary perforation; DIG016 — Peritonitis and intra-abdominal abscess.

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 CC — 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.

K57.20 — Diverticulitis of large intestine with perforation and abscess without bleeding, K57.21 — Diverticulitis of large intestine with perforation and abscess with bleeding, K57.30 — Diverticulosis of large intestine without perforation or abscess without bleeding, K57.31 — Diverticulosis of large intestine without perforation or abscess with bleeding, K57.32 — Diverticulitis of large intestine without perforation or abscess without bleeding, K57.33 — Diverticulitis of large intestine without perforation or abscess with bleeding, K57.40 — Diverticulitis of both small and large intestine with perforation and abscess without bleeding, K57.41 — Diverticulitis of both small and large intestine with perforation and abscess with bleeding, K57.50 — Diverticulosis of both small and large intestine without perforation or abscess without bleeding, K57.51 — Diverticulosis of both small and large intestine without perforation or abscess with bleeding, K57.52 — Diverticulitis of both small and large intestine without perforation or abscess without bleeding, K57.53 — Diverticulitis of both small and large intestine without perforation or abscess with bleeding, K57.81 — Diverticulitis of intestine, part unspecified, with perforation and abscess with bleeding, K57.90 — Diverticulosis of intestine, part unspecified, without perforation or abscess without bleeding, K57.91 — Diverticulosis of intestine, part unspecified, without perforation or abscess with bleeding, K57.92 — Diverticulitis of intestine, part unspecified, without perforation or abscess without bleeding, K57.93 — Diverticulitis of intestine, part unspecified, without perforation or abscess with bleeding

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical categories (Diverticulosis and diverticulitis, Gastrointestinal and biliary perforation, Peritonitis and intra-abdominal abscess).

K57.30 — Diverticulosis of large intestine without perforation or abscess without bleeding, K57.31 — Diverticulosis of large intestine without perforation or abscess with bleeding, K57.32 — Diverticulitis of large intestine without perforation or abscess without bleeding, K57.33 — Diverticulitis of large intestine without perforation or abscess with bleeding, K57.40 — Diverticulitis of both small and large intestine with perforation and abscess without bleeding, K57.41 — Diverticulitis of both small and large intestine with perforation and abscess with bleeding, K57.50 — Diverticulosis of both small and large intestine without perforation or abscess without bleeding, K57.51 — Diverticulosis of both small and large intestine without perforation or abscess with bleeding, K57.52 — Diverticulitis of both small and large intestine without perforation or abscess without bleeding, K57.53 — Diverticulitis of both small and large intestine without perforation or abscess with bleeding, K57.81 — Diverticulitis of intestine, part unspecified, with perforation and abscess with bleeding, K57.90 — Diverticulosis of intestine, part unspecified, without perforation or abscess without bleeding, K57.91 — Diverticulosis of intestine, part unspecified, without perforation or abscess with bleeding, K57.92 — Diverticulitis of intestine, part unspecified, without perforation or abscess without bleeding, K57.93 — Diverticulitis of intestine, part unspecified, without perforation or abscess with bleeding, K61.0 — Anal abscess, K61.1 — Rectal abscess, K61.2 — Anorectal abscess, K61.3 — Ischiorectal abscess, K61.31 — Horseshoe abscess, +65 more

Same Index main term, other category

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

K13.0 — Diseases of lips (lip), K13.79 — Other lesions of oral mucosa (uvula), K14.0 — Glossitis (tongue), K20.80 — Other esophagitis without bleeding (esophagus), K22.3 — Perforation of esophagus (esophagus), K31.89 — Other diseases of stomach and duodenum (stomach), K35.209 — Acute appendicitis with generalized peritonitis, without abscess, unspecified as to perforation (with or following, appendicitis, generalized), K35.30 — Acute appendicitis with localized peritonitis, without perforation or gangrene (with or following, appendicitis, localized), K35.32 — Acute appendicitis with perforation, localized peritonitis, and gangrene, without abscess (appendix), K35.33 — Acute appendicitis with perforation, localized peritonitis, and gangrene, with abscess (cecum), K61.0 — Anal abscess (anus), K61.1 — Rectal abscess (rectum), K61.2 — Anorectal abscess (anorectal), K61.31 — Horseshoe abscess (horseshoe), K61.39 — Other ischiorectal abscess (ischiorectal), K61.4 — Intrasphincteric abscess (intersphincteric), K61.5 — Supralevator abscess (supralevator), K63.0 — Abscess of intestine (fecal), K63.1 — Perforation of intestine (nontraumatic) (colon), K65.0 — Generalized (acute) peritonitis (acute), +384 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, Prothrombin Time Test and INR (PT/INR)

Contextual Map

Every relationship of K57.80 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 K57.80 with these 3 related codes 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-fy2026
• K55-K64 — Other diseases of intestines[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• K92.2 — Gastrointestinal hemorrhage, unspecified[Excludes1](via K57.-): “diverticular disease with hemorrhage (K57.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Code Also instructions

• K65 — Peritonitis[Code Also](via K57.-): “if applicable diverticular disease of intestine (K57.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• K6A.0 — Pelvic abscess[Code Also](via K57.-): “diverticular disease of intestine (K57.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• DIG013 — Diverticulosis and diverticulitis[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
• DIG006 — Gastrointestinal and biliary perforation[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)
• DIG016 — Peritonitis and intra-abdominal abscess[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• CC — Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (CC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
• 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) · FY2026
• 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) · FY2026

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. 5,744 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic), with, diverticular disease (intestine)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Diverticulitis (acute), intestine, with, abscess, perforation[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Perforation, perforated (nontraumatic) (of), diverticulum (intestine)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion), with or following, diverticular disease (intestine)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Rupture, ruptured, diverticulum (intestine)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (32)

• K57 — Diverticular disease of intestine[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• K57.0 — Diverticulitis of small intestine with perforation and abscess[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• K57.00 — Diverticulitis of small intestine with perforation and abscess without bleeding[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• K57.01 — Diverticulitis of small intestine with perforation and abscess with bleeding[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• K57.1 — Diverticular disease of small intestine without perforation or abscess[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• K57.10 — Diverticulosis of small intestine without perforation or abscess without bleeding[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• K57.11 — Diverticulosis of small intestine without perforation or abscess with bleeding[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• K57.12 — Diverticulitis of small intestine without perforation or abscess without bleeding[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 24 more

Change history (5)

• FY2027 — Code Also note will be added[Change history]— CMS release files (code change ledger) · icd10cm-fy2027
• and 4 more

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 FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Coding guidelines Official source data

ICD-10-CM Official Guidelines for Coding and Reporting (FY2026), quoted by section Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 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 — v43 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 structured 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 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.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to K57.80 in its code family, with their registry titles.

• K57.50 — Diverticulosis of both small and large intestine without perforation or abscess without bleeding
• K57.51 — Diverticulosis of both small and large intestine without perforation or abscess with bleeding
• K57.52 — Diverticulitis of both small and large intestine without perforation or abscess without bleeding
• K57.53 — Diverticulitis of both small and large intestine without perforation or abscess with bleeding
• K57.8 — Diverticulitis of intestine, part unspecified, with perforation and abscess
• K57.81 — Diverticulitis of intestine, part unspecified, with perforation and abscess with bleeding
• K57.9 — Diverticular disease of intestine, part unspecified, without perforation or abscess
• K57.90 — Diverticulosis of intestine, part unspecified, without perforation or abscess without bleeding
• K57.91 — Diverticulosis of intestine, part unspecified, without perforation or abscess with bleeding
• K57.92 — Diverticulitis of intestine, part unspecified, without perforation or abscess without bleeding

View all codes in the K57 family