C22.1 vs C24
C22.1 and C24 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 C24
malignant neoplasm of intrahepatic bile duct (C22.1)
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
Malignant neoplasm of other and unspecified parts of biliary tract
Not billable
- Chapter 2
- Neoplasms
- Section
- C15-C26
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