K57.92: Diverticulitis of intestine, part unspecified, without perforation or abscess without bleeding

The ICD-10-CM code for diverticulitis documented without perforation, abscess or bleeding when the record does not name the affected segment of intestine.

Billable

FY2027

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At a glance

Code Family

K57: Diverticular disease of intestine.

Condition

Diverticulitis

DRG Grouping

MS-DRG 391 or 392 within MDC 06 under the FY2027 MS-DRG v44 grouper, depending on whether a major complication or comorbidity is also reported.

HCC Mapping (v28)

None. K57.92 does not map to a CMS-HCC payment category under version 28.

Family Specificity

Twenty four billable child codes split on three axes at once: intestinal site, inflammation present or absent, complication present or absent.

Effective Date

Valid in the FY2026 code set and unchanged in the FY2027 update.

Which K57 code do I assign?

The K57 family splits on three axes at once: the intestinal site, whether inflammation is present, whether perforation with abscess or bleeding is present. Site fixes the subcategory, inflammation separates the diverticulitis codes from the diverticulosis codes, perforation with abscess moves the case to a different subcategory, bleeding sets the final digit.

When documentation says…

Code

Acute diverticulitis with no segment named

K57.92

Active inflammation is documented without perforation, without abscess, without bleeding. The record does not state which part of the intestine is involved. This is the Alphabetic Index default for diverticulitis carrying no further qualification.

Sigmoid diverticulitis or colonic diverticulitis

K57.32

Diverticulitis of the large intestine, which includes the sigmoid, descending and any other colonic segment. Code K57.30 in the same subcategory carries the inclusion term Diverticular disease of colon NOS, which places colonic disease in the K57.3 subcategory.

Ileal diverticulitis or jejunal diverticulitis

K57.12

Diverticulitis of the small intestine without perforation, abscess or bleeding. The Alphabetic Index routes ileum to the small intestine entry.

Diverticulitis of both small and large intestine

K57.52

Both segments are documented as inflamed, without perforation, abscess or bleeding. Subcategories K57.1 and K57.3 each carry an Excludes1 note pointing to the K57.5 codes. One code covers both sites.

Diverticular abscess or perforated diverticulitis, site not named

K57.80

Perforation and abscess move the encounter out of subcategory K57.9 and into K57.8. Assign K57.81 instead when bleeding is also documented. No diverticulosis code exists on this axis, because every child of K57.0, K57.2, K57.4 and K57.8 reads as diverticulitis.

Diverticulitis with diverticular bleeding, site not named

K57.93

Inflammation with hemorrhage, still without perforation or abscess. The final digit carries the bleeding. A separate gastrointestinal hemorrhage code is not added for the diverticular bleed itself.

Diverticulosis or diverticular disease with no inflammation

K57.90

Diverticula are present without documented inflammation. K57.90 carries the inclusion term Diverticular disease of intestine NOS, which makes it the default when the note says only diverticular disease.

Tabular notes

EXCLUDES1

Category K57 carries an Excludes1 note for congenital diverticulum of intestine (Q43.8) and for Meckel's diverticulum (Q43.0). Excludes1 means those codes are not reported with K57.92 for the same condition. Subcategory K57.9 carries no Excludes1 note of its own. This is unlike K57.1 and K57.3, which each exclude the K57.5 codes for combined small and large intestine involvement.

EXCLUDES2

Category K57 carries an Excludes2 note for diverticulum of appendix (K38.2). Excludes2 means the condition is not part of K57, and the patient may carry both. Report K38.2 in addition to K57.92 when appendiceal diverticulum is documented alongside intestinal diverticulitis.

CODE ALSO

Code also, if applicable: pelvic abscess (K6A.0-) and peritonitis (the K65 codes). The FY2027 update added the pelvic abscess entry. The instruction sits at the K57 category level and therefore reaches K57.92. Category K65 and new subcategory K6A.0 each carry the reciprocal instruction to code also, if applicable, diverticular disease of intestine (the K57 codes). A Code also note gives no sequencing direction under FY2027 Official Guidelines Section I.A.17. Sequencing follows the circumstances of the encounter. A documented perforation or walled-off abscess directs the encounter to the K57.8 codes instead.

FY2027: EFFECTIVE 1 OCTOBER 2026

K57.92 is valid in the FY2026 code set and unchanged in the FY2027 update, which took effect on 1 October 2026. No code in category K57 was added, deleted or revised. The FY2027 tabular addenda revised the Code also note at K57 to add pelvic abscess (K6A.0-) alongside peritonitis (the K65 codes). The same update created category K6A, Diseases of the pelvis, not elsewhere classified, with the pelvic abscess codes K6A.01 and K6A.09. The Excludes1 and Excludes2 notes at K57 are unchanged.

Operational & financial impact

Why specificity matters beyond the chart: risk adjustment, DRG assignment and denial exposure all follow from which code is selected.

CMS-HCC v28 (PY2024+)

K57.92 does not map to a CMS-HCC category under version 28.

Category K57 does not appear in the v28 code list for HCC 78, Intestinal Obstruction/Perforation, which is the digestive category nearest to diverticular disease.

K57.80, the unspecified-site code with perforation and abscess, also carries no v28 HCC.

Diverticulitis coded to K57.92 therefore contributes nothing to a Medicare Advantage risk score.

Specificity on this family pays off in MS-DRG assignment and in medical necessity rather than in risk adjustment.

MS-DRG v44 (FY2027)

MS-DRG 391: Esophagitis, gastroenteritis and miscellaneous digestive disorders with MCC.

MS-DRG 392: Esophagitis, gastroenteritis and miscellaneous digestive disorders without MCC.

K57.92 as a principal diagnosis groups to MS-DRG 391 or 392 within MDC 06 under the FY2027 MS-DRG v44 grouper.

That pair splits on MCC alone and carries no with-CC tier. K57.92 lands in MS-DRG 392 unless a separate MCC is reported on the claim.

K57.92 is itself designated a CC on the FY2027 MS-DRG v44 complication or comorbidity list. It is not an MCC.

Reported as a secondary diagnosis, K57.92 can move a stay to the with-CC tier of a DRG family that carries one.

A qualifying operating room procedure on the same admission moves the case into an MDC 06 surgical MS-DRG rather than 391 or 392.

WHERE SPECIFICITY IS LOST

K57.92 records that diverticulitis was present. It records nothing about where.

The workup for suspected acute diverticulitis is CT of the abdomen and pelvis, named the most appropriate initial imaging modality by the 2020 ASCRS clinical practice guideline. A CT report describes the involved segment.

When the record names the colon, the sigmoid or any other colonic segment, the supported code is K57.32, diverticulitis of large intestine without perforation or abscess without bleeding.

The American College of Physicians guideline on acute diverticulitis addresses left-sided colonic disease, which it describes as the most common presentation in Western countries.

K57.92 also records nothing about complications. The ASCRS definition of complicated diverticulitis covers free perforation with a systemic inflammatory response, fistula, abscess, stricture and obstruction.

Only perforation with abscess and bleeding sit on the K57 axis. A documented fistula, stricture or obstruction is reported with a separate code.

Medicare and commercial payers

There is no National Coverage Determination specific to diverticular disease diagnosis coding.

K57.92 is valid for submission in the FY2027 period, 1 October 2026 through 30 September 2027.

These MS-DRG rules apply to Medicare fee-for-service inpatient claims.

SEVERITY DESIGNATION (MS-DRG V44.0)

K57.92 is a CC. It appears in Appendix G, diagnoses defined as complications or comorbidities, in the ICD-10 MS-DRG Definitions Manual Version 44.0. As a secondary diagnosis it can move a case to a with-CC tier where the DRG pair offers one.

Documentation checklist to support K57.92

Chart elements that support code selection and reduce specificity-driven denials.

A provider statement of diverticulitis, meaning documented inflammation. A note reading diverticulosis or diverticular disease directs the encounter to K57.90 instead.

The intestinal site, stated as small intestine, large intestine or colon, or as both. Where the site is absent the encounter falls to K57.92.

An explicit statement that no perforation and no abscess are present, because perforation with abscess directs the encounter to K57.80.

An explicit statement that no bleeding is present, because diverticular bleeding directs the encounter to K57.93.

The CT report of the abdomen and pelvis, which identifies the involved segment and supports a site-specific code.

Any documented peritonitis or pelvic abscess, to support the Code also instruction at K57.

Any documented fistula, stricture or obstruction, which sit outside the K57 perforation axis and are reported separately.

For outpatient encounters, a confirmed diagnosis. Suspected or rule-out diverticulitis is not coded as confirmed in the outpatient setting.

FAQ

Is K57.92 a billable ICD-10-CM code?

Yes. K57.92 is a billable code. It is valid in the FY2026 code set and unchanged in the FY2027 update, which runs 1 October 2026 to 30 September 2027. The parent subcategory K57.9 is not billable, because four child codes below it carry greater detail.

What is the difference between K57.92 and K57.90?

K57.92 is diverticulitis, meaning the diverticula are inflamed. K57.90 is diverticulosis, meaning diverticula are present without documented inflammation. Across the K57 family the final digits 0 and 1 are diverticulosis, and the final digits 2 and 3 are diverticulitis. K57.90 also carries the inclusion term Diverticular disease of intestine NOS, which makes it the code for a note reading only diverticular disease.

When should I assign K57.32 instead of K57.92?

Assign K57.32 whenever the record names a colonic segment, including the sigmoid. K57.32 is diverticulitis of large intestine without perforation or abscess without bleeding. The Alphabetic Index directs diverticulitis of the large intestine to K57.32, and code K57.30 in the same subcategory carries the inclusion term Diverticular disease of colon NOS.

Does K57.92 map to a CMS-HCC under version 28?

No. K57.92 carries no CMS-HCC v28 payment category. Category K57 does not appear in the v28 code list for HCC 78, Intestinal Obstruction/Perforation. Specificity within K57 changes MS-DRG assignment rather than a risk score.

Is K57.92 a CC or an MCC for inpatient DRG assignment?

K57.92 is designated a CC on the FY2027 MS-DRG v44 complication or comorbidity list. It is not an MCC. As a principal diagnosis it groups to MS-DRG 391 or 392. That pair splits on MCC alone and carries no with-CC tier. The CC designation therefore earns nothing when K57.92 is the principal diagnosis. It earns its tier only when K57.92 is a secondary diagnosis on a stay grouped elsewhere.

What must the record show to support K57.92?

The note must establish three things. Inflammation must be documented, which means the word diverticulitis rather than diverticulosis. Perforation and abscess must be absent. Bleeding must be absent. The missing element, a named intestinal site, is what leaves the encounter on K57.92 rather than on K57.12, K57.32 or K57.52.

How does K57.92 sequence against peritonitis, and does the care setting change the rules?

Category K57 carries a Code also instruction for peritonitis (K65.-) and, from FY2027, for pelvic abscess (the K6A.0 codes). Under FY2027 Official Guidelines Section I.A.17 a Code also note gives no sequencing direction. Sequencing follows the circumstances of the encounter. The setting changes one thing. On the inpatient side an uncertain diagnosis documented at discharge may be coded as confirmed, while in the outpatient setting a suspected or rule-out diverticulitis is not.

Did anything change for K57.92 in FY2027?

K57.92 itself is unchanged in the FY2027 update, effective 1 October 2026. That update revises the K57 Code also note to add pelvic abscess (the K6A.0 codes). The descriptor and the category K57 notes were unchanged in the FY2026 code set that took effect 1 October 2025. The April 1, 2026 mid-year update added no diagnosis codes. Its one Chapter 11 change was the deletion of an Excludes1 note under category K60.

Related codes

Codes in the same family as K57.92. Only codes with a published page render as links.

Sibling codes in the K57 family

K57.00: Diverticulitis of small intestine with perforation and abscess without bleeding.
K57.01: Diverticulitis of small intestine with perforation and abscess with bleeding.
K57.10: Diverticulosis of small intestine without perforation or abscess without bleeding.
K57.11: Diverticulosis of small intestine without perforation or abscess with bleeding.
K57.12: Diverticulitis of small intestine without perforation or abscess without bleeding.
K57.13: Diverticulitis of small intestine without perforation or abscess with bleeding.
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.
K57.80: Diverticulitis of intestine, part unspecified, with perforation and abscess without 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.
K57.93: Diverticulitis of intestine, part unspecified, without perforation or abscess with bleeding.

Additional codes to consider

Codes outside the K57 family considered alongside K57.92.

Companion: code alongside when documented

K65-: Peritonitis, called for by the Code also instruction at category K57 when peritonitis is documented.
K65.0: Generalized (acute) peritonitis.
K65.9: Peritonitis, unspecified.
K6A.0-: Pelvic abscess, called for by the Code also instruction at category K57 when a pelvic abscess is documented.
K38.2: Diverticulum of appendix, permitted alongside K57.92 by the Excludes2 note at category K57.

Consider instead

K57.32: Diverticulitis of large intestine without perforation or abscess without bleeding, where the note names the colon or the sigmoid.
K57.12: Diverticulitis of small intestine without perforation or abscess without bleeding.
K57.52: Diverticulitis of both small and large intestine without perforation or abscess without bleeding.
K57.93: Diverticulitis of intestine, part unspecified, without perforation or abscess with bleeding.
K57.80: Diverticulitis of intestine, part unspecified, with perforation and abscess without bleeding.
K57.90: Diverticulosis of intestine, part unspecified, without perforation or abscess without bleeding, where no inflammation is documented.
K57.30: Diverticulosis of large intestine without perforation or abscess without bleeding.
Q43.0: Meckel's diverticulum (displaced) (hypertrophic), excluded from K57 by an Excludes1 note.
Q43.8: Other specified congenital malformations of intestine, the code for congenital diverticulum of intestine.
Z87.19: Personal history of other diseases of the digestive system, for a resolved episode with no current disease.

Sources

All claims on this page derive from government and professional-standards sources.

National Center for Health Statistics. (2026). International classification of diseases, tenth revision, clinical modification (ICD-10-CM) FY2027 files. https://www.cdc.gov/nchs/icd/icd-10-cm/files.html
Centers for Medicare & Medicaid Services and National Center for Health Statistics. (2026). ICD-10-CM official guidelines for coding and reporting FY2027. https://ftp.cdc.gov/pub/Health_Statistics/NCHS/Publications/ICD10CM/2027/ICD-10-CM-October-1-2026-FY27-Guidelines.pdf
Centers for Medicare & Medicaid Services. (2025). 2026 model software/ICD-10 mappings. https://www.cms.gov/medicare/payment/medicare-advantage-rates-statistics/risk-adjustment/2026-model-software-icd-10-mappings
Centers for Medicare & Medicaid Services. (2026). MS-DRG classifications and software, version 44. https://www.cms.gov/medicare/payment/prospective-payment-systems/acute-inpatient-pps/ms-drg-classifications-and-software