2026 ICD-10-CM Diagnosis Code C04Malignant neoplasm of floor of mouth

ICD-10-CM Codes›C00–D49›C00-C14›C04

ICD-10-CM C04
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C04 is a non-billable ICD-10-CM category code for malignant neoplasm of floor of mouth, so it cannot be submitted on claims. Use a more specific code from this category instead, such as C04.0, C04.1, C04.8, and C04.9.

Code Identity

ICD-10-CM Code
C04
Billable Status
No — Non-Billable Category
Code Describes
Malignant neoplasm of floor of mouth
Short Description
Malignant neoplasm of floor of mouth
Same as the full description in the CMS dataset.
Chapter
C00-C14
Malignant neoplasms of lip, oral cavity and pharynx

Code Classification

ChapterC00–D49Neoplasms
SectionC00-C14Malignant neoplasms of lip, oral cavity and pharynx
CategoryC04Malignant neoplasm of floor of mouth
This CodeC04Malignant neoplasm of floor of mouth

Specific Coding for Malignant neoplasm of floor of mouthOverview

Non-specific codes like C04 require more characters. Use one of these billable codes instead:

  • Use C04.0 for Malignant neoplasm of anterior floor of mouth

  • Use C04.1 for Malignant neoplasm of lateral floor of mouth

  • Use C04.8 for Malignant neoplasm of overlapping sites of floor of mouth

  • Use C04.9 for Malignant neoplasm of floor of mouth, unspecified

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Use Additional Code

  • code to identify:
  • alcohol abuse and dependence F10
  • history of tobacco dependence Z87.891
  • tobacco dependence F17
  • tobacco use Z72.0

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.

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 C04Overview

Is C04 (Malignant neoplasm of floor of mouth) a billable code?

No. This is a category header that groups the codes for malignant neoplasm of floor of mouth, and headers cannot be submitted on claims. Claims for malignant neoplasm of floor of mouth need a more specific code from this category, such as C04.0, C04.1, and C04.8.