2026 ICD-10-CM Diagnosis Code C24.9Malignant neoplasm of biliary tract, unspecified

ICD-10-CM Codes›C00–D49›C15-C26›C24

ICD-10-CM C24.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C24.9 is a billable ICD-10-CM diagnosis code for malignant neoplasm of biliary tract, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 435 through 437. Coders also document this condition as carcinoma liver and/or biliary system. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Gastrointestinal cancers - all other types.

Code Identity

ICD-10-CM Code
C24.9
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm of biliary tract, unspecified
Short Description
Malignant neoplasm of biliary tract, unspecified
Same as the full description in the CMS dataset.
Parent Code
C24
Malignant neoplasm of other and unspecified parts of biliary tract

Code Classification

ChapterC00–D49Neoplasms
SectionC15-C26Malignant neoplasms of digestive organs
CategoryC24Malignant neoplasm of other and unspecified parts of biliary tract
This CodeC24.9Malignant neoplasm of biliary tract, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carcinoma liver and/or biliary system
  • Malignant neoplasm of biliary tract
  • Malignant polyp of biliary tract
  • Primary adenocarcinoma of biliary tract
  • Primary carcinoma liver and/or biliary system
  • Primary malignant neoplasm of biliary tract
  • Primary mucinous cystic neoplasm with associated invasive carcinoma of biliary tract

Clinical ClassificationClinical

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

CCSR NEO021
Gastrointestinal cancers - all other types
Default principal diagnosis: inpatient Yes · outpatient Yes

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary		Malig.
Secondary		Ca
in situ		BenignUncertainUnspec.
bile or biliary (tract)C24.9C78.89D01.5D13.5D37.6D49.0
hepatobiliaryC24.9C78.89D01.5D13.5D37.6D49.0

Patient EducationClinical

Bile Duct Cancer

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.

The full article covers:

  • What is Bile Duct Cancer (Cholangiocarcinoma)?

Read the full article at MedlinePlus

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

Convert C24.9 to ICD-9-CMHistory

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

ICD-9-CM
156.9 Malig neo biliary NOS
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 C24.9Overview

Is C24.9 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of biliary tract, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does C24.9 group to?

When malignant neoplasm of biliary tract, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 435, 436, 437, with relative weights from 0.8533 to 1.8367 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of C24.9?

Under the General Equivalence Mappings, malignant neoplasm of biliary tract, unspecified converts to ICD-9-CM 156.9 (malig neo biliary NOS). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.