Is ICD-10-CM code C04 billable?

No, C04 (Malignant neoplasm of floor of mouth) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code C04 belong to?

C04 belongs to Chapter 2 of the ICD-10-CM tabular list: C00–D49 (Neoplasms).

C04Not billable, use a more specific code below

Malignant neoplasm of floor of mouth

In Malignant neoplasms of lip, oral cavity and pharynx (C00-C14), chapter 2: Neoplasms

4 billable codes under C04: none are a CC or MCC; all map to HCC 21 (Lymphoma and Other Cancers).An HCC counts toward a Medicare Advantage patient's risk score.

Instructional notes

Use additional code: add a second code for this, listed after this one

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

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Rules for coding benign and malignant neoplasms: using the Neoplasm Table, sequencing primary and secondary sites, treatment encounters, complications, and current cancer versus personal history.

Admission/Encounter for treatment of primary site (page 33)
Admission/Encounter for treatment of secondary site (page 33)
Coding and sequencing of complications (page 34)
Primary malignancy previously excised (page 34)
Admissions/Encounters involving antineoplastic chemotherapy, immunotherapy and radiation therapy (page 35)
Admission/encounter to determine extent of malignancy (page 36)
Symptoms, signs, and abnormal findings listed in Chapter 18 associated with neoplasms (page 36)
Admission/encounter for pain control/management (page 36)

Read Section I.C.2 (page 32), 12 more topics

All codes under C04

C04 can't be used on a claim. Pick a billable code below; grey headings group them.

C04 MS-DRGs

This code does not group to an MS-DRG as a principal diagnosis.

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

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.

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.