2026 ICD-10-CM Diagnosis Code C00.1Malignant neoplasm of external lower lip
ICD-10-CM Codes›C00–D49›C00-C14›C00
- Billable — Valid for Submission
- Chronic Condition
C00.1 is a billable ICD-10-CM diagnosis code for malignant neoplasm of external lower lip. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 11 through 13, 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.
- Carcinoma of vermilion border of lower lip
- Carcinoma of vermilion of lower lip
- Malignant neoplasm of lower lip, external
- Malignant neoplasm of vermilion border of lower lip
- Malignant neoplasm of vermilion of lip
- Malignant neoplasm of vermilion of lower lip
- Primary carcinoma of lip
- Primary carcinoma of vermilion border of lower lip
- Primary carcinoma of vermilion of lower lip
- Primary malignant neoplasm of vermilion border of lip
- Primary malignant neoplasm of vermilion border of lower lip
- Primary squamous cell carcinoma of lip
- Primary squamous cell carcinoma of vermilion border of lip
- Primary squamous cell carcinoma of vermilion border of lower lip
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Malignant neoplasm of lower lip NOS
- Malignant neoplasm of lipstick area of lower lip
- Malignant neoplasm of vermilion border of lower lip
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.
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 C00.1 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About C00.1Overview
What is the ICD-10 code for malignant neoplasm of external lower lip?
The ICD-10-CM code for malignant neoplasm of external lower lip is C00.1 (sometimes written as C001). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is C00.1 (Malignant neoplasm of lip) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of external lower lip on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does C00.1 group to?
When malignant neoplasm of external lower lip is the principal diagnosis on an inpatient stay, it groups to MS-DRG 11, 12, 13, 146, 147, 148, with relative weights from 0.7971 to 5.4541 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of C00.1?
Under the General Equivalence Mappings, malignant neoplasm of external lower lip converts to ICD-9-CM 140.1 (mal neo lower vermilion). The mapping is a direct match.
