2026 ICD-10-CM Diagnosis Code C03.0Malignant neoplasm of upper gum

ICD-10-CM CodesC00–D49C00-C14C03

ICD-10-CM C03.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C03.0 is a billable ICD-10-CM diagnosis code for malignant neoplasm of upper gum. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 146 through 148. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Head and neck cancers - lip and oral cavity.

Code Identity

ICD-10-CM Code
C03.0
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm of upper gum
Short Description
Malignant neoplasm of upper gum
Same as the full description in the CMS dataset.
Parent Code
Malignant neoplasm of gum

Code Classification

ChapterC00–D49Neoplasms
SectionC00-C14Malignant neoplasms of lip, oral cavity and pharynx
CategoryC03Malignant neoplasm of gum
This CodeC03.0Malignant neoplasm of upper gum

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Carcinoma of upper gum
  • Malignant neoplasm of alveolus of maxilla
  • Malignant neoplasm of upper gum
  • Neoplasm of upper gum
  • Primary carcinoma of upper gum
  • Primary malignant neoplasm of gum
  • Primary malignant neoplasm of upper gum
  • Primary squamous cell carcinoma of upper gum

Clinical ClassificationClinical

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

CCSR NEO002
Head and neck cancers - lip and oral cavity
Default principal diagnosis: inpatient Yes · outpatient Yes

Table of NeoplasmsClinical

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

SiteMalig.
Primary
Malig.
Secondary
Ca
in situ
BenignUncertainUnspec.
alveolar mucosa upperC03.0C79.89D00.03D10.39D37.09D49.0
alveolar ridge or process carcinoma upperC03.0C79.8
alveolar ridge or process mucosa upperC03.0C79.89D00.03D10.39D37.09D49.0
alveolus upperC03.0C79.89D00.03D10.39D37.09D49.0
gingiva (alveolar) (marginal) maxillaryC03.0C79.89D00.03D10.39D37.09D49.0
gingiva (alveolar) (marginal) upperC03.0C79.89D00.03D10.39D37.09D49.0
gum upperC03.0C79.89D00.03D10.39D37.09D49.0
interdental papillae upperC03.0C79.89D00.03D10.39D37.09D49.0
jaw soft tissues upperC03.0C79.89D00.03D10.39D37.09D49.0
maxilla, maxillary (superior) alveolarC03.0C79.89D00.03D10.39D37.09D49.0
maxilla, maxillary (superior) alveolar mucosaC03.0C79.89D00.03D10.39D37.09D49.0
maxilla, maxillary (superior) carcinomaC03.0C79.51
mucosa alveolar (ridge or process) upperC03.0C79.89D00.03D10.39D37.09D49.0

Patient EducationClinical

Oral Cancer

Oral cancer is cancer of the mouth. It is a type of head and neck cancer. Most oral cancers are squamous cell cancers. They begin in the flat cells that cover the surfaces of your mouth, tongue, and lips. The cancer cells may spread into deeper tissue as the cancer grows.

The full article covers:

  • What is oral cancer?
  • Who is more likely to develop oral cancer?
  • What are the symptoms of oral cancer?
  • How is oral cancer diagnosed?
  • What are the treatments for oral cancer?
  • Can oral cancer be prevented?

Read the full article at MedlinePlus

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

Convert C03.0 to ICD-9-CMHistory

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

ICD-9-CM
143.0 Malig neo upper gum
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 C03.0Overview

Is C03.0 (Malignant neoplasm of gum) a billable code?

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

What MS-DRG does C03.0 group to?

When malignant neoplasm of upper gum is the principal diagnosis on an inpatient stay, it groups to MS-DRG 146, 147, 148, with relative weights from 0.7971 to 2.1174 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of C03.0?

Under the General Equivalence Mappings, malignant neoplasm of upper gum converts to ICD-9-CM 143.0 (malig neo upper gum). 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.