2026 ICD-10-CM Diagnosis Code C17.1Malignant neoplasm of jejunum

ICD-10-CM Codes›C00–D49›C15-C26›C17

ICD-10-CM C17.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C17.1 is a billable ICD-10-CM diagnosis code for malignant neoplasm of jejunum. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 374 through 376. Coders also document this condition as adenocarcinoma of small intestine. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Gastrointestinal cancers - small intestine.

Code Identity

ICD-10-CM Code
C17.1
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm of jejunum
Short Description
Malignant neoplasm of jejunum
Same as the full description in the CMS dataset.
Parent Code
C17
Malignant neoplasm of small intestine

Code Classification

ChapterC00–D49Neoplasms
SectionC15-C26Malignant neoplasms of digestive organs
CategoryC17Malignant neoplasm of small intestine
This CodeC17.1Malignant neoplasm of jejunum

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Adenocarcinoma of small intestine
  • Malignant neoplasm of jejunum
  • Primary adenocarcinoma of jejunum
  • Primary adenocarcinoma of small intestine
  • Primary malignant neoplasm of jejunum

Clinical ClassificationClinical

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

CCSR NEO014
Gastrointestinal cancers - small intestine
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Jejunal Neoplasms

    tumors or cancer in the jejunum region of the small intestine (intestine, small).

  • Jejunum

    the middle portion of the small intestine, between duodenum and ileum. it represents about 2/5 of the remaining portion of the small intestine below duodenum.

Table of NeoplasmsClinical

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

SiteMalig.
Primary		Malig.
Secondary		Ca
in situ		BenignUncertainUnspec.
intestine, intestinal › small › jejunumC17.1C78.4D01.49D13.39D37.2D49.0
jejunumC17.1C78.4D01.49D13.39D37.2D49.0

Patient EducationClinical

Intestinal Cancer

Your small intestine is part of your digestive system. It is a long tube that connects your stomach to your large intestine. Intestinal cancer is rare, but eating a high-fat diet or having Crohn's disease, celiac disease, or a history of colonic polyps can increase your risk.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert C17.1 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
152.1 Malignant neopl jejunum
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 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About C17.1Overview

Is C17.1 (Malignant neoplasm of small intestine) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of jejunum on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does C17.1 group to?

When malignant neoplasm of jejunum is the principal diagnosis on an inpatient stay, it groups to MS-DRG 374, 375, 376, with relative weights from 0.9243 to 2.1387 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of C17.1?

Under the General Equivalence Mappings, malignant neoplasm of jejunum converts to ICD-9-CM 152.1 (malignant neopl jejunum). 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.