2026 ICD-10-CM Diagnosis Code C22.1Intrahepatic bile duct carcinoma
ICD-10-CM Codes›C00–D49›C15-C26›C22
- Billable — Valid for Submission
- Chronic Condition
C22.1 is a billable ICD-10-CM diagnosis code for intrahepatic bile duct carcinoma. 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 - bile duct.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Adenocarcinoma of liver and intrahepatic biliary tract
- Cholangiocarcinoma of biliary tract
- Cholangiocarcinoma of intrahepatic biliary tract
- Intrahepatic bile duct carcinoma
- Malignant neoplasm of interlobular bile ducts
- Malignant neoplasm of intrahepatic bile duct
- Malignant neoplasm of intrahepatic canaliculi
- Metastatic cholangiocarcinoma
- Primary adenocarcinoma of bile duct
- Primary adenocarcinoma of intrahepatic bile duct
- Primary carcinoma liver and/or biliary system
- Primary carcinoma of bile duct
- Primary cholangiocarcinoma of biliary tract
- Primary cholangiocarcinoma of intrahepatic biliary tract
- Primary cystadenocarcinoma of intrahepatic bile duct
- Primary intrahepatic bile duct carcinoma
- Primary malignant neoplasm of intrahepatic bile duct
- Primary squamous cell carcinoma of liver and intrahepatic biliary tract
- Primary undifferentiated carcinoma of liver and intrahepatic biliary tract
- Squamous cell carcinoma of liver and intrahepatic biliary tract
- Undifferentiated carcinoma of liver and intrahepatic biliary tract
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Cholangiocarcinoma
Type 1 Excludes
- malignant neoplasm of hepatic duct C24.0
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Adenocarcinoma - See Also: Neoplasm, malignant, by site;
- bile duct type - C22.1
- liver - C22.1
- unspecified site - C22.1
- Cancer - See Also: Neoplasm, by site, malignant;
- bile duct type liver - C22.1
- Carcinoma (malignant) - See Also: Neoplasm, by site, malignant;
- liver - C22.1
- unspecified site - C22.1
- liver - C22.1
- unspecified site - C22.1
- Cystadenocarcinoma - See: Neoplasm, malignant, by site;
- bile duct - C22.1
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Adenocarcinoma
- bile duct type
- Adenocarcinoma
- bile duct type
- liver
- Adenocarcinoma
- bile duct type
- unspecified site
- Cancer
- bile duct type liver
- Carcinoma(malignant)
- bile duct
- liver
- Carcinoma(malignant)
- bile duct
- unspecified site
- Cholangiocarcinoma
- liver
- Cholangiocarcinoma
- unspecified site
- Cystadenocarcinoma
- bile duct
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Metastatic Cholangiocarcinoma
a cholangiocarcinoma that has metastasized to other anatomic sites.
Table of NeoplasmsClinical
Anatomical sites in the Table of Neoplasms that reference this code family.
| Site | Malig. Primary | Malig. Secondary | Ca in situ | Benign | Uncertain | Unspec. |
|---|---|---|---|---|---|---|
| bile or biliary (tract) › canaliculi (biliferi) (intrahepatic) | C22.1 | C78.7 | D01.5 | D13.4 | D37.6 | D49.0 |
| bile or biliary (tract) › canals, interlobular | C22.1 | C78.89 | D01.5 | D13.4 | D37.6 | D49.0 |
| bile or biliary (tract) › duct or passage (common) (cystic) (extrahepatic) › interlobular | C22.1 | C78.89 | D01.5 | D13.4 | D37.6 | D49.0 |
| bile or biliary (tract) › duct or passage (common) (cystic) (extrahepatic) › intrahepatic | C22.1 | C78.7 | D01.5 | D13.4 | D37.6 | D49.0 |
| canaliculi, biliary (biliferi) (intrahepatic) | C22.1 | C78.7 | D01.5 | D13.4 | D37.6 | D49.0 |
| cholangiole | C22.1 | C78.89 | D01.5 | D13.4 | D37.6 | D49.0 |
| gall duct (extrahepatic) › intrahepatic | C22.1 | C78.7 | D01.5 | D13.4 | D37.6 | D49.0 |
| intrahepatic (bile) duct | C22.1 | C78.7 | D01.5 | D13.4 | D37.6 | D49.0 |
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.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert C22.1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C22.1Overview
Is C22.1 (Malignant neoplasm of liver and intrahepatic bile ducts) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report intrahepatic bile duct carcinoma on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C22.1 group to?
When intrahepatic bile duct carcinoma 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 C22.1?
Under the General Equivalence Mappings, intrahepatic bile duct carcinoma converts to ICD-9-CM 155.1 (mal neo intrahepat ducts). 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.
