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ICD-10-CM C22.1: Intrahepatic bile duct carcinoma

C22.1 is the billable ICD-10-CM code for intrahepatic bile duct carcinoma, in category C22 (Malignant neoplasm of liver and intrahepatic bile ducts) of the Malignant neoplasms of digestive organs section. As a principal diagnosis it groups to MS-DRG 435 Malignancy of Hepatobiliary System or Pancreas with MCC, MS-DRG 436 Malignancy of Hepatobiliary System or Pancreas with CC, MS-DRG 437 Malignancy of Hepatobiliary System or Pancreas without CC/MCC (MDC 07 MDC 07: Diseases and Disorders of the Hepatobiliary System and Pancreas). It maps to HCC 20 (Lung and Other Severe Cancers) in CMS-HCC V28. As a secondary diagnosis it is a CC, excluded with 26 principal diagnoses. 56 LCD billing and coding articles list it as covered.

Compiled from CMS files by the QuickIntell RCM Editorial Team · Data effective · Method: reference methodology · Report a data correction

Data currency: ICD-10-CM code descriptions: FY2027 (effective October 1, 2026); IPPS Table 5 (MS-DRG weights): v44 FY2027 (final rule + CN3) (effective October 1, 2026); ICD-10-CM to HCC mapping: PY2027 initial ICD-10-CM mappings (dates of service 2026) (payment year 2027); Medicare Coverage Database billing and coding articles: MCD release October 8, 2026 (effective October 4, 2026). Next CMS release: FY2028 code files, effective October 1, 2027 for the ICD-10-CM code descriptions; FY2028 final rule (August 2027), effective October 1, 2027; an April 1 interim grouper update when CMS issues one for the IPPS Table 5 (MS-DRG weights); PY2028 advance notice (February 2027) and the PY2027 midyear final mapping (spring 2027) for the ICD-10-CM to HCC mapping; weekly, every Thursday for the Medicare Coverage Database billing and coding articles.

Code
C22.1
billable FY2027 ICD-10-CM code
Category
C22 Malignant neoplasm of liver and intrahepatic bile ducts
Chapter
2: Neoplasms (C00-D49)
CC/MCC (MS-DRG v44)
CC
CMS-HCC V28
HCC 20
POA reporting
Required

Tabular list notes for C22.1

Inclusion terms
  • Cholangiocarcinoma
Excludes1 (never coded together)
  • malignant neoplasm of hepatic duct (C24.0)

Inherited from C22 (Malignant neoplasm of liver and intrahepatic bile ducts)

Excludes1 (never coded together)
  • malignant neoplasm of biliary tract NOS (C24.9)
  • secondary malignant neoplasm of liver and intrahepatic bile duct (C78.7)
Use additional code
  • code to identify:
  • alcohol abuse and dependence (F10.-)
  • hepatitis B (B16.-, B18.0-B18.1)
  • hepatitis C (B17.1-, B18.2)

MS-DRG grouping when C22.1 is the principal diagnosis

MS-DRG v44 groups for C22.1 as principal diagnosis
MDCMS-DRGs
07 MDC 07: Diseases and Disorders of the Hepatobiliary System and Pancreas435436437

The final group also depends on procedures, secondary diagnoses and discharge status; the MS-DRG lookup for C22.1 shows the full grouping logic.

CC/MCC status and inpatient edits

As a secondary diagnosis, C22.1 is a CC under MS-DRG v44, unless the principal diagnosis is one of the 26 codes in its exclusion list. Check C22.1 against a principal diagnosis.

  • Present on admission: a POA indicator is required on inpatient claims.

CMS-HCC V28 risk adjustment

In the PY2027 mapping, C22.1 maps to HCC 20 (Lung and Other Severe Cancers). The HCC lookup shows the RAF weight and the hierarchy.

LCD billing and coding articles that list C22.1

56 current Medicare billing and coding articles list C22.1 among the diagnoses that support medical necessity for the services they cover.

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Frequently asked questions

What does ICD-10-CM C22.1 mean?

C22.1 means intrahepatic bile duct carcinoma. The tabular list also files these terms under it: Cholangiocarcinoma. It is one of 8 billable codes under C22, malignant neoplasm of liver and intrahepatic bile ducts.

What can't be coded with C22.1?

Excludes1 at C22.1: malignant neoplasm of hepatic duct (C24.0). These are never reported together with C22.1.

Which MS-DRG does C22.1 group to?

As the principal diagnosis, C22.1 groups to MS-DRG 435 Malignancy of Hepatobiliary System or Pancreas with MCC, MS-DRG 436 Malignancy of Hepatobiliary System or Pancreas with CC, MS-DRG 437 Malignancy of Hepatobiliary System or Pancreas without CC/MCC (MDC 07 MDC 07: Diseases and Disorders of the Hepatobiliary System and Pancreas) under MS-DRG v44, before procedures and secondary diagnoses are applied.

Does C22.1 map to an HCC?

Yes: HCC 20, Lung and Other Severe Cancers, in the PY2027 CMS-HCC V28 mapping.

Is C22.1 a CC or MCC?

C22.1 is a CC under MS-DRG v44; 26 principal diagnoses exclude it.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

Disclaimer

The descriptor and notes are reproduced from the FY2027 ICD-10-CM files; MS-DRG, CC/MCC and HCC facts come from the CMS FY2027 and PY2027 tables. Code from the medical record and the ICD-10-CM Official Guidelines. Not legal, clinical or billing advice.

Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.