2026 ICD-10-CM Diagnosis Code C16.4Malignant neoplasm of pylorus
ICD-10-CM Codes›C00–D49›C15-C26›C16
- Billable — Valid for Submission
- Chronic Condition
C16.4 is a billable ICD-10-CM diagnosis code for malignant neoplasm of pylorus. 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 carcinoma of pylorus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Gastrointestinal cancers - stomach.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Carcinoma of pylorus
- Leiomyosarcoma of pylorus of stomach
- Leiomyosarcoma of stomach
- Lymphoma of pylorus of stomach
- Malignant neoplasm of pyloric canal of stomach
- Malignant neoplasm of pylorus of stomach
- Primary adenocarcinoma of pyloric antrum of stomach
- Primary adenocarcinoma of pylorus
- Primary carcinoma of pylorus
- Primary malignant neoplasm of pylorus
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Malignant neoplasm of prepylorus
- Malignant neoplasm of pyloric canal
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.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Pyloric Stenosis
narrowing of the pyloric canal with varied etiology. a common form is due to muscle hypertrophy (pyloric stenosis, hypertrophic) seen in infants.Pylorus
the region of the stomach at the junction with the duodenum. it is marked by the thickening of circular muscle layers forming the pyloric sphincter to control the opening and closure of the lumen.
Table of NeoplasmsClinical
Anatomical sites in the Table of Neoplasms that reference this code family.
Patient EducationClinical
Stomach Cancer
The stomach is an organ between the esophagus and the small intestine. It mixes food with stomach acid and helps digest protein. Stomach cancer mostly affects older people - two-thirds of people who have it are over age 65. Your risk of getting it is also higher if you:
The full article covers:
- What is Stomach Cancer?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert C16.4 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C16.4Overview
Is C16.4 (Malignant neoplasm of stomach) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of pylorus on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C16.4 group to?
When malignant neoplasm of pylorus 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 C16.4?
Under the General Equivalence Mappings, malignant neoplasm of pylorus converts to ICD-9-CM 151.1 (malignant neo pylorus). 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.
