2026 ICD-10-CM Diagnosis Code K91.86Retained cholelithiasis following cholecystectomy

ICD-10-CM Codes›K00–K95›K90-K95›K91

ICD-10-CM K91.86
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K91.86 is a billable ICD-10-CM diagnosis code for retained cholelithiasis following cholecystectomy. 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 Postprocedural or postoperative digestive system complication.

Code Identity

ICD-10-CM Code
K91.86
Billable Status
Yes — Valid for Submission
Code Describes
Retained cholelithiasis following cholecystectomy
Short Description
Retained cholelithiasis following cholecystectomy
Same as the full description in the CMS dataset.
Parent Code
K91.8
Other intraoperative and postprocedural complications and disorders of digestive system

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 CodeK91.86Retained cholelithiasis following cholecystectomy

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.

    • Retained
      • cholelithiasis following cholecystectomy
    • Retained
      • gallstones, following cholecystectomy
    • Retention
      • cholelithiasis following cholecystectomy
    • Retention
      • gallstones, following cholecystectomy

Clinical ClassificationClinical

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

CCSR DIG024
Postprocedural or postoperative digestive system complication
Default principal diagnosis: inpatient Yes · outpatient Yes

Convert K91.86 to ICD-9-CMHistory

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

ICD-9-CM
997.41 Ret cholelh fol cholecys
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 K91.86Overview

Is K91.86 a billable code?

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

What MS-DRG does K91.86 group to?

When retained cholelithiasis following cholecystectomy 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 K91.86?

Under the General Equivalence Mappings, retained cholelithiasis following cholecystectomy converts to ICD-9-CM 997.41 (ret cholelh fol cholecys). 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.