2026 ICD-10-CM Diagnosis Code K80.31Calculus of bile duct with cholangitis, unspecified, with obstruction

ICD-10-CM Codes›K00–K95›K80-K87›K80

ICD-10-CM K80.31
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K80.31 is a billable ICD-10-CM diagnosis code for calculus of bile duct with cholangitis, unspecified, with obstruction. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 444 through 446. Coders also document this condition as cholangitis due to bile duct calculus with obstruction. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Biliary tract disease.

Code Identity

ICD-10-CM Code
K80.31
Billable Status
Yes — Valid for Submission
Code Describes
Calculus of bile duct with cholangitis, unspecified, with obstruction
Short Description
Calculus of bile duct w cholangitis, unsp, with obstruction
Parent Code
K80.3
Calculus of bile duct with cholangitis

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK80-K87Disorders of gallbladder, biliary tract and pancreas
CategoryK80Cholelithiasis
This CodeK80.31Calculus of bile duct with cholangitis, unspecified, with obstruction

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Cholangitis due to bile duct calculus with obstruction

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.

    • Calculus, calculi, calculous
      • bile duct (common) (hepatic)
        • with
          • cholangitis
            • with
              • obstruction

Clinical ClassificationClinical

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

CCSR DIG017
Biliary tract disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Bile Duct Diseases

Your liver makes a digestive juice called bile. Your gallbladder stores it between meals. When you eat, your gallbladder pushes the bile into tubes called bile ducts. They carry the bile to your small intestine. The bile helps break down fat. It also helps the liver get rid of toxins and wastes.

Read the full article at MedlinePlus

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

Convert K80.31 to ICD-9-CMHistory

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

ICD-9-CM
574.51 Choledochlith NOS w obst
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
576.1 Cholangitis
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

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 K80.31Overview

Is K80.31 (Calculus of bile duct with cholangitis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report calculus of bile duct with cholangitis, unspecified, with obstruction on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does K80.31 group to?

When calculus of bile duct with cholangitis, unspecified, with obstruction is the principal diagnosis on an inpatient stay, it groups to MS-DRG 444, 445, 446, with relative weights from 0.8273 to 1.6709 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of K80.31?

Under the General Equivalence Mappings, calculus of bile duct with cholangitis, unspecified, with obstruction converts to ICD-9-CM 574.51 (choledochlith NOS w obst) and 576.1 (cholangitis). The mapping is approximate, so confirm the match fits the documentation.

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.