C22.1 vs C24.0
C22.1 and C24.0 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on C22.1
malignant neoplasm of hepatic duct (C24.0)
C22.1
Intrahepatic bile duct carcinoma
Billable
- Chapter 2
- Neoplasms
- Section
- C15-C26
Use when the record says
- Cholangiocarcinoma
Indexed under
- Adenocarcinoma › bile duct type
- Cancer › bile duct type liver
- Cholangiocarcinoma › liver
- Cholangiocarcinoma › unspecified site
- Cystadenocarcinoma › bile duct
C24.0
Malignant neoplasm of extrahepatic bile duct
Billable
- Chapter 2
- Neoplasms
- Section
- C15-C26
Use when the record says
- Malignant neoplasm of biliary duct or passage NOS
- Malignant neoplasm of common bile duct
- Malignant neoplasm of cystic duct
- Malignant neoplasm of hepatic duct
Indexed under
- Klatskin's tumor
- Tumor › Klatskin's
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027