2026 ICD-10-CM Diagnosis Code K58.2Mixed irritable bowel syndrome

ICD-10-CM Codes›K00–K95›K55-K64›K58

ICD-10-CM K58.2
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K58.2 is a billable ICD-10-CM diagnosis code for mixed irritable bowel syndrome. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 391 through 392. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified gastrointestinal disorders.

Code Identity

ICD-10-CM Code
K58.2
Billable Status
Yes — Valid for Submission
Code Describes
Mixed irritable bowel syndrome
Short Description
Mixed irritable bowel syndrome
Same as the full description in the CMS dataset.
Parent Code
K58
Irritable bowel syndrome

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK55-K64Other diseases of intestines
CategoryK58Irritable bowel syndrome
This CodeK58.2Mixed irritable bowel syndrome

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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

Clinical InformationClinical

  • Irritable Bowel Syndrome

    a disorder with chronic or recurrent colonic symptoms without a clearcut etiology. this condition is characterized by chronic or recurrent abdominal pain, bloating, mucus in feces, and an erratic disturbance of defecation.

Patient EducationClinical

Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a problem that affects the large intestine. It can cause abdominal cramping, bloating, and a change in bowel habits. Some people with the disorder have constipation. Some have diarrhea. Others go back and forth between the two.

Read the full article at MedlinePlus

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

Convert K58.2 to ICD-9-CMHistory

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

ICD-9-CM
564.1 Irritable bowel syndrome
Approximate The match is approximate rather than exact.

Code History & ChangesHistory

Replacement K58.2 replaces the following previously assigned code(s):

  • K58.9 - Irritable bowel syndrome without diarrhea
  • K58.9 - Irritable bowel syndrome, unspecified
FY 2019AddedAdded to the ICD-10-CM code setEffective October 1, 2018.
FY 2020–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About K58.2Overview

What is the ICD-10 code for mixed irritable bowel syndrome?

The ICD-10-CM code for mixed irritable bowel syndrome is K58.2 (sometimes written as K582). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is K58.2 (Irritable bowel syndrome) a billable code?

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

What MS-DRG does K58.2 group to?

When mixed irritable bowel syndrome is the principal diagnosis on an inpatient stay, it groups to MS-DRG 391, 392, with relative weights from 0.7796 to 1.2683 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of K58.2?

Under the General Equivalence Mappings, mixed irritable bowel syndrome converts to ICD-9-CM 564.1 (irritable bowel syndrome). The mapping is approximate, so confirm the match fits the documentation.