2026 ICD-10-CM Diagnosis Code K31.5Obstruction of duodenum

ICD-10-CM Codes›K00–K95›K20-K31›K31

ICD-10-CM K31.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K31.5 is a billable ICD-10-CM diagnosis code for obstruction of duodenum. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 380 through 382. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Intestinal obstruction and ileus.

Code Identity

ICD-10-CM Code
K31.5
Billable Status
Yes — Valid for Submission
Code Describes
Obstruction of duodenum
Short Description
Obstruction of duodenum
Same as the full description in the CMS dataset.
Parent Code
K31
Other diseases of stomach and duodenum

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK20-K31Diseases of esophagus, stomach and duodenum
CategoryK31Other diseases of stomach and duodenum
This CodeK31.5Obstruction of duodenum

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute duodenal ulcer with hemorrhage
  • Acute duodenal ulcer with hemorrhage AND obstruction
  • Acute duodenal ulcer with hemorrhage AND perforation
  • Acute duodenal ulcer with hemorrhage, with perforation AND with obstruction
  • Acute duodenal ulcer with obstruction
  • Acute duodenal ulcer with perforation
  • Acute duodenal ulcer with perforation AND obstruction
  • Acute duodenal ulcer without hemorrhage AND without perforation
  • Acute duodenal ulcer without hemorrhage AND without perforation but with obstruction
  • Acute peptic ulcer with hemorrhage AND obstruction
  • Acute peptic ulcer with hemorrhage, with perforation AND with obstruction
  • Acute peptic ulcer with perforation AND obstruction
  • Chronic duodenal ileus
  • Chronic duodenal ulcer with hemorrhage
  • Chronic duodenal ulcer with hemorrhage AND obstruction
  • Chronic duodenal ulcer with hemorrhage AND perforation
  • Chronic duodenal ulcer with hemorrhage, with perforation AND with obstruction
  • Chronic duodenal ulcer with obstruction
  • Chronic duodenal ulcer with perforation
  • Chronic duodenal ulcer with perforation AND obstruction
  • Chronic duodenal ulcer without hemorrhage AND without perforation
  • Chronic duodenal ulcer without hemorrhage AND without perforation but with obstruction
  • Chronic peptic ulcer with hemorrhage AND obstruction
  • Chronic peptic ulcer with hemorrhage AND perforation
  • Chronic peptic ulcer with hemorrhage, with perforation AND with obstruction
  • Chronic peptic ulcer with perforation AND obstruction
  • Duodenal papillary stenosis
  • Duodenal scar
  • Duodenal ulcer with hemorrhage AND obstruction
  • Duodenal ulcer with hemorrhage AND perforation
  • Duodenal ulcer with hemorrhage, with perforation AND with obstruction
  • Duodenal ulcer with perforation AND obstruction
  • Duodenal ulcer without hemorrhage AND without perforation
  • Duodenal ulcer without hemorrhage AND without perforation but with obstruction
  • Intestinal volvulus
  • Obstruction of duodenum
  • Stenosis of duodenum
  • Stricture of duodenum
  • Stricture of small intestine
  • Volvulus of duodenum
  • Volvulus of small intestine

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Constriction of duodenum
  • Duodenal ileus (chronic)
  • Stenosis of duodenum
  • Stricture of duodenum
  • Volvulus of duodenum

Type 1 Excludes

  • congenital stenosis of duodenum Q41.0

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Cicatrix(adherent) (contracted) (painful) (vicious)
      • duodenum (bulb), obstructive
    • Constriction
      • duodenum
    • Ileus(bowel) (colon) (inhibitory) (intestine)
      • duodenal (chronic)
    • Obstruction, obstructed, obstructive
      • duodenum
    • Scar, scarring
      • duodenum, obstructive
    • Stasis
      • duodenal
    • Stenosis, stenotic(cicatricial)
      • duodenum
    • Stricture
      • duodenum
    • Syndrome
      • aortomesenteric duodenum occlusion
    • Volvulus(bowel) (colon) (intestine)
      • duodenum

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR DIG012
Intestinal obstruction and ileus
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Intestinal Volvulus

    a twisting in the intestine (intestines) that can cause intestinal obstruction.

  • Intestinal Volvulus

    twisting of a loop of bowel that results in intestinal obstruction.

Patient EducationClinical

Intestinal Obstruction

An intestinal obstruction occurs when food or stool cannot move through the intestines. The obstruction can be complete or partial. There are many causes. The most common are adhesions, hernias, cancers, and certain medicines.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert K31.5 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
537.2 Chronic duodenal ileus
Approximate The match is approximate rather than exact.
ICD-9-CM
537.3 Duodenal obstruction NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About K31.5Overview

Is K31.5 (Other diseases of stomach and duodenum) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report obstruction of duodenum on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does K31.5 group to?

When obstruction of duodenum is the principal diagnosis on an inpatient stay, it groups to MS-DRG 380, 381, 382, with relative weights from 0.8006 to 1.9622 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of K31.5?

Under the General Equivalence Mappings, obstruction of duodenum converts to ICD-9-CM 537.2 (chronic duodenal ileus) and 537.3 (duodenal obstruction NEC). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.