2026 ICD-10-CM Diagnosis Code K55.1Chronic vascular disorders of intestine

ICD-10-CM Codes›K00–K95›K55-K64›K55

ICD-10-CM K55.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K55.1 is a billable ICD-10-CM diagnosis code for chronic vascular disorders of intestine. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 393 through 395. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified gastrointestinal disorders and Peripheral and visceral vascular disease.

Code Identity

ICD-10-CM Code
K55.1
Billable Status
Yes — Valid for Submission
Code Describes
Chronic vascular disorders of intestine
Short Description
Chronic vascular disorders of intestine
Same as the full description in the CMS dataset.
Parent Code
K55
Vascular disorders of intestine

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK55-K64Other diseases of intestines
CategoryK55Vascular disorders of intestine
This CodeK55.1Chronic vascular disorders of intestine

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abdominal angina
  • Atherosclerosis of abdominal visceral artery
  • Atherosclerosis of superior mesenteric artery
  • Chronic gastrointestinal tract vascular insufficiency
  • Chronic inflammatory small bowel disease
  • Chronic ischemic colitis
  • Chronic ischemic enteritis
  • Chronic ischemic enterocolitis
  • Chronic vascular insufficiency
  • Chronic vascular insufficiency of intestine
  • Insufficiency of mesenteric artery
  • Ischemic colitis
  • Ischemic enteritis of intestine
  • Ischemic enterocolitis
  • Ischemic stricture of intestine
  • Mesenteric artery stenosis
  • Non-occlusive mesenteric ischemia

Tabular List NotesGuidance

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

Inclusion Terms

  • Chronic ischemic colitis
  • Chronic ischemic enteritis
  • Chronic ischemic enterocolitis
  • Ischemic stricture of intestine
  • Mesenteric atherosclerosis
  • Mesenteric vascular insufficiency

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.

    • Abdomen, abdominal
      • angina
    • Angina(attack) (cardiac) (chest) (heart) (pectoris) (syndrome) (vasomotor)
      • abdominal
    • Angina(attack) (cardiac) (chest) (heart) (pectoris) (syndrome) (vasomotor)
      • intestinal
    • Angina(attack) (cardiac) (chest) (heart) (pectoris) (syndrome) (vasomotor)
      • mesenteric
    • Arteriosclerosis, arteriosclerotic(diffuse) (obliterans) (of) (senile) (with calcification)
      • mesenteric (artery)
    • Colitis(acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)
      • ischemic
        • chronic
    • Colitis(acute) (catarrhal) (chronic) (noninfective) (hemorrhagic)
      • ischemic
        • due to mesenteric artery insufficiency
    • Disease, diseased
      • Wilkie's
    • Disorder(of)
      • intestine, intestinal
        • vascular
          • chronic
    • Enteritis(acute) (diarrheal) (hemorrhagic) (noninfective)
      • ischemic
        • chronic
    • Enterocolitis
      • hemorrhagic (acute)
        • chronic
    • Insufficiency, insufficient
      • arterial
        • mesenteric
    • Insufficiency, insufficient
      • mesenteric
    • Insufficiency, insufficient
      • vascular
        • mesenteric
    • Ischemia, ischemic
      • bowel (transient)
        • chronic
    • Ischemia, ischemic
      • bowel (transient)
        • due to mesenteric artery insufficiency
    • Ischemia, ischemic
      • colon chronic (due to mesenteric artery insufficiency)
    • Ischemia, ischemic
      • intestine (large) (small) (transient)
        • chronic
    • Ischemia, ischemic
      • intestine (large) (small) (transient)
        • due to mesenteric artery insufficiency
    • Ischemia, ischemic
      • small bowel
        • chronic
    • Ischemia, ischemic
      • small bowel
        • due to mesenteric artery insufficiency
    • Stricture
      • intestine
        • ischemic
    • Syndrome
      • ischemic
        • bowel (transient)
          • chronic
    • Syndrome
      • ischemic
        • bowel (transient)
          • due to mesenteric artery insufficiency
    • Syndrome
      • mesenteric
        • artery (superior)
    • Syndrome
      • mesenteric
        • vascular insufficiency
    • Syndrome
      • superior
        • mesenteric artery
    • Syndrome
      • Wilkie's
    • Wilkie's disease or syndrome

Clinical ClassificationClinical

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

CCSR DIG025
Other specified and unspecified gastrointestinal disorders
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR CIR026
Peripheral and visceral vascular disease
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Digestive Diseases

When you eat, your body breaks food down to a form it can use to build and nourish cells and provide energy. This process is called digestion.

Read the full article at MedlinePlus

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

Convert K55.1 to ICD-9-CMHistory

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

ICD-9-CM
557.1 Chr vasc insuff intest
Exact Match The mapping is direct, with no qualifiers.

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 K55.1Overview

Is K55.1 (Vascular disorders of intestine) a billable code?

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

What MS-DRG does K55.1 group to?

When chronic vascular disorders of intestine is the principal diagnosis on an inpatient stay, it groups to MS-DRG 393, 394, 395, with relative weights from 0.6490 to 1.5993 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of K55.1?

Under the General Equivalence Mappings, chronic vascular disorders of intestine converts to ICD-9-CM 557.1 (chr vasc insuff intest). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.