2026 ICD-10-CM Diagnosis Code C06.9Malignant neoplasm of mouth, unspecified
ICD-10-CM Codes›C00–D49›C00-C14›C06
- Billable — Valid for Submission
- Chronic Condition
C06.9 is a billable ICD-10-CM diagnosis code for malignant neoplasm of mouth, unspecified. 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
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Kaposi sarcoma of internal part of mouth
- Malignant melanoma of mucous membrane
- Malignant melanoma of oral cavity
- Malignant neoplasm of minor salivary gland
- Malignant neoplasm of oral cavity
- Malignant neoplasm of oral cavity and lip and salivary gland
- Neoplasm of minor salivary gland
- Neoplasm of oral cavity and lip and salivary gland
- Primary malignant melanoma of oral mucous membrane
- Primary malignant neoplasm of minor salivary gland
- Primary malignant neoplasm of oral cavity
- Primary rhabdomyosarcoma of head
- Primary rhabdomyosarcoma of oral cavity
- Primary squamous cell carcinoma of oral cavity
- Primary verrucous carcinoma of oral cavity
- Primary verrucous squamous cell carcinoma
- Squamous cell carcinoma of mouth
- Verrucous carcinoma of oral cavity
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Malignant neoplasm of minor salivary gland, unspecified site
- Malignant neoplasm of oral cavity NOS
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.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Table of NeoplasmsClinical
Anatomical sites in the Table of Neoplasms that reference this code family.
| Site | Malig. Primary | Malig. Secondary | Ca in situ | Benign | Uncertain | Unspec. |
|---|---|---|---|---|---|---|
| buccal (cavity) | C06.9 | C79.89 | D00.00 | D10.39 | D37.09 | D49.0 |
| cavity | C06.9 | C79.89 | D00.00 | D10.30 | D37.09 | D49.0 |
| cavity › buccal | C06.9 | C79.89 | D00.00 | D10.30 | D37.09 | D49.0 |
| cavity › oral | C06.9 | C79.89 | D00.00 | D10.30 | D37.09 | D49.0 |
| mouth | C06.9 | C79.89 | D00.00 | D10.30 | D37.09 | D49.0 |
| oral (cavity) | C06.9 | C79.89 | D00.00 | D10.30 | D37.09 | D49.0 |
| salivary gland or duct (major) › minor NEC | C06.9 | C79.89 | D00.00 | D10.39 | D37.04 | D49.0 |
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 C06.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C06.9Overview
Is C06.9 (Malignant neoplasm of other and unspecified parts of mouth) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of mouth, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C06.9 group to?
When malignant neoplasm of mouth, unspecified 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 C06.9?
Under the General Equivalence Mappings, malignant neoplasm of mouth, unspecified converts to ICD-9-CM 145.9 (malig neoplasm mouth NOS). 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.
