2026 ICD-10-CM Diagnosis Code D37.1Neoplasm of uncertain behavior of stomach

ICD-10-CM CodesC00–D49D37-D48D37

ICD-10-CM D37.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D37.1 is a billable ICD-10-CM diagnosis code for neoplasm of uncertain behavior of stomach. 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 neoplasm of uncertain behavior of body of stomach. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Neoplasms of unspecified nature or uncertain behavior.

Code Identity

ICD-10-CM Code
D37.1
Billable Status
Yes — Valid for Submission
Code Describes
Neoplasm of uncertain behavior of stomach
Short Description
Neoplasm of uncertain behavior of stomach
Same as the full description in the CMS dataset.
Parent Code
Neoplasm of uncertain behavior of oral cavity and digestive organs

Code Classification

ChapterC00–D49Neoplasms
SectionD37-D48Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes
CategoryD37Neoplasm of uncertain behavior of oral cavity and digestive organs
This CodeD37.1Neoplasm of uncertain behavior of stomach

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Neoplasm of uncertain behavior of body of stomach
  • Neoplasm of uncertain behavior of cardia of stomach
  • Neoplasm of uncertain behavior of fundus of stomach
  • Neoplasm of uncertain behavior of greater curvature of stomach
  • Neoplasm of uncertain behavior of lesser curvature of stomach
  • Neoplasm of uncertain behavior of pyloric antrum
  • Neoplasm of uncertain behavior of pylorus
  • Neoplasm of uncertain behavior of stomach

Clinical ClassificationClinical

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

CCSR NEO072
Neoplasms of unspecified nature or uncertain behavior
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Esophagogastric Junction

    the area covering the terminal portion of esophagus and the beginning of stomach at the cardiac orifice.
  • 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.
  • Bariatric Surgery

    surgical procedures aimed at affecting metabolism and producing major weight reduction in patients with morbid obesity.
  • Diverticulosis, Stomach

    a pathological condition characterized by the presence of a number of gastric diverticula in the stomach.
  • Diverticulum, Stomach

    saccular, outward protrusion of all or a portion of the wall of the stomach.
  • Gastric Absorption

    uptake of substances via the stomach.
  • Gastric Antral Vascular Ectasia

    a distinct vascular lesion in the pyloric antrum that is characterized by tortuous dilated blood vessels (ectasia) radiating outward from the pylorus. the vessel pattern resembles the stripes on the surface of a watermelon. this lesion causes both acute and chronic gastrointestinal hemorrhage.
  • Gastric Dilatation

    abnormal distention of the stomach due to accumulation of gastric contents that may reach 10 to 15 liters. gastric dilatation may be the result of gastric outlet obstruction; ileus; gastroparesis; or denervation.
  • Gastric Fistula

    abnormal passage communicating with the stomach.
  • Gastric Stump

    that portion of the stomach remaining after gastric surgery, usually gastrectomy or gastroenterostomy for cancer of the stomach or peptic ulcer. it is a common site of cancer referred to as stump cancer or carcinoma of the gastric stump.
  • Gastrointestinal Contents

    the contents included in all or any segment of the gastrointestinal tract.
  • Receptor-Like Protein Tyrosine Phosphatases, Class 3

    a subclass of receptor-like protein tryosine phosphatases that contain a single cytosolic protein tyrosine phosphate domain and multiple extracellular fibronectin iii-like domains.
  • Stomach

    an organ of digestion situated in the left upper quadrant of the abdomen between the termination of the esophagus and the beginning of the duodenum.
  • Stomach Diseases

    pathological processes involving the stomach.
  • Stomach Neoplasms

    tumors or cancer of the stomach.
  • Stomach Rupture

    bursting of the stomach.
  • Stomach Ulcer

    ulceration of the gastric mucosa due to contact with gastric juice. it is often associated with helicobacter pylori infection or consumption of nonsteroidal anti-inflammatory drugs (nsaids).
  • Stomach Volvulus

    twisting of the stomach that may result in gastric ischemia and gastric outlet obstruction. it is often associated with diaphragmatic hernia.
  • Stomach, Avian

    a component of the digestive system of birds which consists of the gizzard and proventriculus.
  • Stomach, Ruminant

    a component of the digestive system of ruminants which consists of the abomasum; omasum; reticulum; and rumen.

Table of NeoplasmsClinical

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

SiteMalig.
Primary
Malig.
Secondary
Ca
in situ
BenignUncertainUnspec.
antrum (Highmore) (maxillary) pyloricC16.3C78.89D00.2D13.1D37.1D49.0
cardia (gastric)C16.0C78.89D00.2D13.1D37.1D49.0
cardiac orifice (stomach)C16.0C78.89D00.2D13.1D37.1D49.0
cardio-esophageal junctionC16.0C78.89D00.2D13.1D37.1D49.0
cardio-esophagusC16.0C78.89D00.2D13.1D37.1D49.0
corpus gastricC16.2C78.89D00.2D13.1D37.1D49.0
esophagogastric junctionC16.0C78.89D00.2D13.1D37.1D49.0
fundusC16.1C78.89D00.2D13.1D37.1D49.0
fundus stomachC16.1C78.89D00.2D13.1D37.1D49.0
gastroesophageal junctionC16.0C78.89D00.2D13.1D37.1D49.0
junction cardioesophagealC16.0C78.89D00.2D13.1D37.1D49.0
junction esophagogastricC16.0C78.89D00.2D13.1D37.1D49.0
junction gastroesophagealC16.0C78.89D00.2D13.1D37.1D49.0
prepylorusC16.4C78.89D00.2D13.1D37.1D49.0
pyloricC16.3C78.89D00.2D13.1D37.1D49.0
pyloric antrumC16.3C78.89D00.2D13.1D37.1D49.0
pyloric canalC16.4C78.89D00.2D13.1D37.1D49.0
pylorusC16.4C78.89D00.2D13.1D37.1D49.0
stomachC16.9C78.89D00.2D13.1D37.1D49.0
stomach antrum (pyloric)C16.3C78.89D00.2D13.1D37.1D49.0
stomach bodyC16.2C78.89D00.2D13.1D37.1D49.0
stomach cardiaC16.0C78.89D00.2D13.1D37.1D49.0
stomach cardiac orificeC16.0C78.89D00.2D13.1D37.1D49.0
stomach corpusC16.2C78.89D00.2D13.1D37.1D49.0
stomach fundusC16.1C78.89D00.2D13.1D37.1D49.0
stomach greater curvature NECC16.6C78.89D00.2D13.1D37.1D49.0
stomach lesser curvature NECC16.5C78.89D00.2D13.1D37.1D49.0
stomach prepylorusC16.4C78.89D00.2D13.1D37.1D49.0
stomach pylorusC16.4C78.89D00.2D13.1D37.1D49.0
stomach wall NECC16.9C78.89D00.2D13.1D37.1D49.0
stomach wall NEC anterior NECC16.8C78.89D00.2D13.1D37.1D49.0
stomach wall NEC posterior NECC16.8C78.89D00.2D13.1D37.1D49.0

Patient EducationClinical

Stomach Disorders

Your stomach is an organ between your esophagus and small intestine. It is where digestion of protein begins. The stomach has three tasks. It stores swallowed food. It mixes the food with stomach acids. Then it sends the mixture on to the small intestine.

Read the full article at MedlinePlus

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

Convert D37.1 to ICD-9-CMHistory

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

ICD-9-CM
235.2 Unc behav neo intestine
Approximate The match is approximate rather than exact.

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 D37.1Overview

Is D37.1 a billable code?

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

What MS-DRG does D37.1 group to?

When neoplasm of uncertain behavior of stomach 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 D37.1?

Under the General Equivalence Mappings, neoplasm of uncertain behavior of stomach converts to ICD-9-CM 235.2 (unc behav neo intestine). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.