2026 ICD-10-CM Diagnosis Code C24.1Malignant neoplasm of ampulla of Vater
ICD-10-CM Codes›C00–D49›C15-C26›C24
- Billable — Valid for Submission
- Chronic Condition
C24.1 is a billable ICD-10-CM diagnosis code for malignant neoplasm of ampulla of Vater. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Gastrointestinal cancers - all other types.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Adenocarcinoma of duodenum
- Adenocarcinoma of small intestine
- Carcinoma common bile duct
- Carcinoma of ampulla of Vater
- Carcinoma of duodenum
- Carcinoma of extrahepatic bile duct
- Malignant neoplasm of ampulla of Vater
- Pancreatic ductal adenocarcinoma
- Primary adenocarcinoma of ampulla of Vater
- Primary adenocarcinoma of bile duct
- Primary adenocarcinoma of common bile duct
- Primary adenocarcinoma of pancreas
- Primary adenocarcinoma of pancreatic duct
- Primary adenocarcinoma of small intestine
- Primary carcinoma common bile duct
- Primary carcinoma liver and/or biliary system
- Primary carcinoma of ampulla of Vater
- Primary carcinoma of bile duct
- Primary carcinoma of duodenum
- Primary carcinoma of extrahepatic bile duct
- Primary carcinoma of pancreas
- Primary malignant neoplasm of ampulla of Vater
- Primary malignant neoplasm of common bile duct
- Primary malignant neoplasm of duodenum
- Primary malignant neoplasm of pancreatic duct
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Ampulla of Vater
a dilation of the duodenal papilla that is the opening of the juncture of the common bile duct and the main pancreatic duct, also known as the hepatopancreatic ampulla.
Table of NeoplasmsClinical
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.
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Convert C24.1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C24.1Overview
Is C24.1 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of ampulla of Vater on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C24.1 group to?
When malignant neoplasm of ampulla of Vater 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 C24.1?
Under the General Equivalence Mappings, malignant neoplasm of ampulla of Vater converts to ICD-9-CM 156.2 (mal neo ampulla of vater). 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.
