ICD-10-CM Code C16.9

Malignant neoplasm of stomach, unspecified

Version 2021 Replaced Code Billable Code Neoplasm Malignant Primary

Valid for Submission

C16.9 is a billable code used to specify a medical diagnosis of malignant neoplasm of stomach, unspecified. The code is valid for the fiscal year 2021 for the submission of HIPAA-covered transactions. The ICD-10-CM code C16.9 might also be used to specify conditions or terms like adenocarcinoma of stomach, carcinoma of stomach, diffusely infiltrative tumor configuration, early gastric cancer, epstein-barr virus associated gastric carcinoma, gastric adenocarcinoma and proximal polyposis of stomach, etc

The following anatomical sites found in the Table of Neoplasms apply to this code given the correct histological behavior: Neoplasm, neoplastic stomach or Neoplasm, neoplastic stomach wall NEC .

Short Description:Malignant neoplasm of stomach, unspecified
Long Description:Malignant neoplasm of stomach, unspecified

Replaced Code

This code was replaced in the 2021 ICD-10 code set with the code(s) listed below. The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2020. This code was replaced for the FY 2021 (October 1, 2020 - September 30, 2021).

  • C49.A2 - Gastrointestinal stromal tumor of stomach
  • C49.A2 - Gastrointestinal stromal tumor of stomach

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code C16.9:

Inclusion Terms

Inclusion Terms
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.
  • Gastric cancer NOS

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code C16.9 are found in the index:


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Adenocarcinoma of stomach
  • Carcinoma of stomach
  • Diffusely infiltrative tumor configuration
  • Early gastric cancer
  • Epstein-Barr virus associated gastric carcinoma
  • Gastric adenocarcinoma and proximal polyposis of stomach
  • Gastric polyp
  • Gastric polyposis
  • Gastroduodenal disorder
  • Hereditary diffuse carcinoma of stomach
  • Late gastric cancer
  • Leiomyosarcoma of stomach
  • Linitis plastica of stomach
  • Local recurrence of malignant tumor of stomach
  • Malignant tumor of esophagus, stomach and duodenum
  • Malignant tumor of stomach
  • Metastasis from malignant tumor of stomach
  • Metastatic gastroesophageal adenocarcinoma
  • pN1: Metastasis in 1 to 6 regional
  • pN2: Metastasis in 7 to 15 regional
  • pN3: Metastasis in more than 15 regional
  • Primary malignant mesenchymal neoplasm of stomach
  • Primary malignant neoplasm of stomach
  • pT1: Tumor invades lamina propria or submucosa
  • pT1a: Tumor invades lamina propria
  • pT1b: Tumor invades submucosa
  • pT2: Tumor invades muscularis propria or subserosa
  • pT2a: Tumor invades muscularis propria
  • pT2b: Tumor invades subserosa
  • pT3: Tumor penetrates serosa
  • pT4: Tumor invades adjacent structures
  • Squamous cell carcinoma of stomach
  • T1a: Esophagus/stomach tumor invades lamina propria
  • T1b: Esophagus/stomach tumor invades submucosa
  • T2: Stomach tumor invades muscularis propria or subserosa
  • T2a: Stomach tumor invades muscularis propria
  • T2b: Stomach tumor invades subserosa
  • T3: Stomach tumor penetrates serosa without invasion of adjacent structures
  • Undifferentiated carcinoma of stomach

Diagnostic Related Groups

The ICD-10 code C16.9 is grouped in the following groups for version MS-DRG V38.0 What are Diagnostic Related Groups?
The Diagnostic Related Groups (DRGs) are a patient classification scheme which provides a means of relating the type of patients a hospital treats. The DRGs divides all possible principal diagnoses into mutually exclusive principal diagnosis areas referred to as Major Diagnostic Categories (MDC).
applicable from 10/01/2020 through 09/30/2021.


Convert C16.9 to ICD-9

  • 151.9 - Malig neopl stomach NOS

Code Classification

  • Neoplasms (C00–D48)
    • Malignant neoplasms of digestive organs (C15-C26)
      • Malignant neoplasm of stomach (C16)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Table of Neoplasms

The code C16.9 is included in the table of neoplasms by anatomical site. For each site there are six possible code numbers according to whether the neoplasm in question is malignant, benign, in situ, of uncertain behavior, or of unspecified nature. The description of the neoplasm will often indicate which of the six columns is appropriate.

Where such descriptors are not present, the remainder of the Index should be consulted where guidance is given to the appropriate column for each morphological (histological) variety listed. However, the guidance in the Index can be overridden if one of the descriptors mentioned above is present.

Neoplasm, neoplastic Malignant
CaInSitu Benign Uncertain
»Neoplasm, neoplastic
»Neoplasm, neoplastic
    »wall NEC

Information for Patients

Stomach Cancer

Also called: Gastric 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

  • Have had a Helicobacter pylori infection
  • Have had stomach inflammation
  • Are a man
  • Eat lots of salted, smoked, or pickled foods
  • Smoke cigarettes
  • Have a family history of stomach cancer

It is hard to diagnose stomach cancer in its early stages. Indigestion and stomach discomfort can be symptoms of early cancer, but other problems can cause the same symptoms. In advanced cases, there may be blood in your stool, vomiting, unexplained weight loss, jaundice, or trouble swallowing. Doctors diagnose stomach cancer with a physical exam, blood and imaging tests, an endoscopy, and a biopsy.

Because it is often found late, it can be hard to treat stomach cancer. Treatment options include surgery, chemotherapy, radiation or a combination.

NIH: National Cancer Institute

  • Abdominal radiation - discharge (Medical Encyclopedia)
  • After chemotherapy - discharge (Medical Encyclopedia)
  • Gastrectomy (Medical Encyclopedia)
  • Radiation enteritis (Medical Encyclopedia)
  • Stomach cancer (Medical Encyclopedia)

[Learn More]