2026 ICD-10-CM Diagnosis Code K91.1Postgastric surgery syndromes
ICD-10-CM Codes›K00–K95›K90-K95›K91
- Billable — Valid for Submission
- Not Chronic
K91.1 is a billable ICD-10-CM diagnosis code for postgastric surgery syndromes. 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 Postprocedural or postoperative digestive system complication.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Alimentary hypoglycemia
- Diarrhea after gastrointestinal tract surgery
- Early dumping syndrome
- Familial duodenal ulcer associated with rapid gastric emptying
- Gastric necrosis
- Late dumping syndrome
- Metabolic complication of procedures
- Non-infective diarrhea
- Post gastrointestinal tract surgery hypoglycemia
- Postgastric surgery syndrome
- Post-vagotomy diarrhea
- Post-vagotomy lesser curve necrosis
- Post-vagotomy syndrome
- Reactive hypoglycemia
- Small stomach syndrome
- Vitamin B12 deficiency anemia following gastrectomy
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Dumping syndrome
- Postgastrectomy syndrome
- Postvagotomy syndrome
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Diarrhea, diarrheal (disease) (infantile) (inflammatory) R19.7
postgastrectomy K91.1
postvagotomy K91.1
Syndrome See Also: Disease;
postgastric surgery K91.1
postvagotomy K91.1
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 K91.1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About K91.1Overview
What is the ICD-10 code for postgastric surgery syndromes?
The ICD-10-CM code for postgastric surgery syndromes is K91.1 (sometimes written as K911). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is K91.1 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report postgastric surgery syndromes on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does K91.1 group to?
When postgastric surgery syndromes 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 K91.1?
Under the General Equivalence Mappings, postgastric surgery syndromes converts to ICD-9-CM 564.2 (postgastric surgery synd). The mapping is a direct match.
