2027 ICD-10-CM Diagnosis Code C22.1Intrahepatic bile duct carcinoma

ICD-10-CM Codes›C00–D49›C15-C26›C22

ICD-10-CM C22.1
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

C22.1 is a billable ICD-10-CM diagnosis code for intrahepatic bile duct carcinoma. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 435 through 437. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 26 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Gastrointestinal cancers - bile duct.

For Medicare Advantage risk adjustment, C22.1 maps to CMS-HCC Category 20 (Lung and Other Severe Cancers) under the V28 model, adding a risk factor of about 1.136 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
C22.1
Billable Status
Yes — Valid for Submission
Code Describes
Intrahepatic bile duct carcinoma
Short Description
Intrahepatic bile duct carcinoma
Same as the full description in the CMS dataset.
Parent Code
C22
Malignant neoplasm of liver and intrahepatic bile ducts

Code Classification

ChapterC00–D49Neoplasms
SectionC15-C26Malignant neoplasms of digestive organs
CategoryC22Malignant neoplasm of liver and intrahepatic bile ducts
This CodeC22.1Intrahepatic bile duct carcinoma

Medicare Risk Adjustment (HCC)Billing

C22.1 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.

CMS-HCC V28 Category (Payment Model)
HCC 20— Lung and Other Severe Cancers
Payment HCC · PY 2027 one of 233 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+1.136
community, non-dual, aged · ranges 0.672–1.214 across segments
Hierarchy
Superseded by HCC 17, HCC 18, and HCC 19
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
HCC 9
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 9 · ESRD (V21): HCC 9 · ESRD (V24): HCC 9
ESRD V21 weights: 0.169 dialysis, 0.604–0.975 functioning graft · ESRD V24 weights: 0.181 dialysis, 0.770–1.226 functioning graft
Part D (RxHCC)
RxHCC 20 — Lung, Kidney, and Other Cancers; Secondary Cancer of Lymph Nodes and Other Sites
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to C22.1: its own notes plus those printed at C22, block C15-C26, and Chapter 2. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Cholangiocarcinoma

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

On C22.1 itself
  • malignant neoplasm of hepatic duct (C24.0)
From C22 Malignant neoplasm of liver and intrahepatic bile ducts applies to 8 codes
  • malignant neoplasm of biliary tract NOS (C24.9)
  • secondary malignant neoplasm of liver and intrahepatic bile duct (C78.7)
From Block C15-C26 Malignant neoplasms of digestive organs applies to 60 codes
  • Kaposi's sarcoma of gastrointestinal sites (C46.4)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block C15-C26 Malignant neoplasms of digestive organs applies to 60 codes
  • gastrointestinal stromal tumors (C49.A-)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From C22 Malignant neoplasm of liver and intrahepatic bile ducts applies to 8 codes

Notes

General instructions on how these codes are used.

From Chapter 2 (C00-D49) Neoplasms applies to 1,730 codes
  • Functional activity
  • All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
  • Morphology [Histology]
  • Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
  • Primary malignant neoplasms overlapping site boundaries
  • A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
  • Malignant neoplasm of ectopic tissue
  • Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name C22.1, its category, or a range that includes it.

Applicable To 2

These notes mention C22.1.

  • Z85.05 Personal history of malignant neoplasm of liver
    Conditions classifiable to C22 names C22, which includes this code
  • Z80.0 Family history of malignant neoplasm of digestive organs
    Conditions classifiable to C15-C26 names C15-C26, which includes this code

Excludes1 1

These codes carry an Excludes1 note naming C22.1: they are not reported together with it, unless the two conditions are unrelated.

  • C24 Malignant neoplasm of other and unspecified parts of biliary tract
    malignant neoplasm of intrahepatic bile duct (C22.1)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO018
Gastrointestinal cancers - bile duct
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Intrahepatic Cholangiocarcinoma

    a carcinoma that arises from the intrahepatic bile duct epithelium in any site of the intrahepatic biliary tree. grossly, the malignant lesions are solid, nodular, and grayish. morphologically, the vast majority of cases are adenocarcinomas. signs and symptoms include malaise, weight loss, right upper quadrant abdominal pain, and night sweats. early detection is difficult and the prognosis is generally poor.

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary		Malig.
Secondary		Ca
in situ		BenignUncertainUnspec.
bile or biliary (tract) › canaliculi (biliferi) (intrahepatic)C22.1C78.7D01.5D13.4D37.6D49.0
bile or biliary (tract) › canals, interlobularC22.1C78.89D01.5D13.4D37.6D49.0
bile or biliary (tract) › duct or passage (common) (cystic) (extrahepatic) › interlobularC22.1C78.89D01.5D13.4D37.6D49.0
bile or biliary (tract) › duct or passage (common) (cystic) (extrahepatic) › intrahepaticC22.1C78.7D01.5D13.4D37.6D49.0
canaliculi, biliary (biliferi) (intrahepatic)C22.1C78.7D01.5D13.4D37.6D49.0
cholangioleC22.1C78.89D01.5D13.4D37.6D49.0
gall duct (extrahepatic) › intrahepaticC22.1C78.7D01.5D13.4D37.6D49.0
intrahepatic (bile) ductC22.1C78.7D01.5D13.4D37.6D49.0

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.

ICD-9-CM
155.1 Mal neo intrahepat ducts
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About C22.1Overview

What is the ICD-10 code for intrahepatic bile duct carcinoma?

The ICD-10-CM code for intrahepatic bile duct carcinoma is C22.1 (sometimes written as C221). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

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 436, 437, 435, with relative weights from 0.8078 to 1.8428 depending on complications. Higher weights mean higher Medicare reimbursement.

Is C22.1 a CC or MCC?

CMS lists C22.1 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 26 closely related codes in its exclusion list.

Can C22.1 be reported with C24.0?

Not as a rule. The Excludes1 note on C22.1 lists "malignant neoplasm of hepatic duct (C24.0)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What HCC is C22.1?

C22.1 (intrahepatic bile duct carcinoma) maps to CMS-HCC Category 20 (Lung and Other Severe Cancers), commonly written as HCC 20, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 9 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 20.

Does C22.1 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, C22.1 adds a risk adjustment factor of about 1.136 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.672 to 1.214 depending on the payment segment). A more severe related category (HCC 17, HCC 18, and HCC 19) supersedes it when both are reported. See the full factor table on the HCC 20 category page.