2026 ICD-10-CM Diagnosis Code K91.0Vomiting following gastrointestinal surgery

ICD-10-CM Codes›K00–K95›K90-K95›K91

ICD-10-CM K91.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K91.0 is a billable ICD-10-CM diagnosis code for vomiting following gastrointestinal surgery. 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. Coders also document this condition as bilious vomiting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nausea and vomiting and Postprocedural or postoperative digestive system complication.

Code Identity

ICD-10-CM Code
K91.0
Billable Status
Yes — Valid for Submission
Code Describes
Vomiting following gastrointestinal surgery
Short Description
Vomiting following gastrointestinal surgery
Same as the full description in the CMS dataset.
Parent Code
K91
Intraoperative and postprocedural complications and disorders of digestive system, not elsewhere classified

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK90-K95Other diseases of the digestive system
CategoryK91Intraoperative and postprocedural complications and disorders of digestive system, not elsewhere classified
This CodeK91.0Vomiting following gastrointestinal surgery

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilious vomiting
  • Bilious vomiting following gastrointestinal surgery
  • Diarrhea after gastrointestinal tract surgery
  • Diarrhea and vomiting after gastrointestinal tract surgery
  • Postoperative vomiting
  • Vomiting after gastrointestinal tract surgery

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.

    • Complication(s) (from) (of)
      • gastrointestinal
        • postoperative
          • vomiting after GI surgery
    • Vomiting
      • bilious (cause unknown)
        • following gastro-intestinal surgery
    • Vomiting
      • following gastrointestinal surgery

Clinical ClassificationClinical

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

CCSR SYM004
Nausea and vomiting
Default principal diagnosis: inpatient No · outpatient No
CCSR DIG024
Postprocedural or postoperative digestive system complication
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

After Surgery

After any operation, you'll have some side effects. There is usually some pain with surgery. There may also be swelling and soreness around the area that the surgeon cut. Your surgeon can tell you which side effects to expect.

Read the full article at MedlinePlus

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

Convert K91.0 to ICD-9-CMHistory

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

ICD-9-CM
564.3 Vomiting post-gi surgery
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 K91.0Overview

Is K91.0 a billable code?

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

What MS-DRG does K91.0 group to?

When vomiting following gastrointestinal surgery 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 K91.0?

Under the General Equivalence Mappings, vomiting following gastrointestinal surgery converts to ICD-9-CM 564.3 (vomiting post-gi surgery). The mapping is a direct match.

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.