ICD-10 Code C00.3 – Malignant neoplasm of upper lip, inner aspect (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C00.3 – Malignant neoplasm of upper lip, inner aspect
What it is
C00.3 identifies a malignant tumor arising on the inner aspect of the upper lip. Use it when documentation specifies this exact lip subsite rather than the outer skin or another oral location.
Clinical signs
Clinical features vary; refer to documentation. Commonly, records describe a persistent ulcer, mass, induration, bleeding, or a nonhealing lesion on the inner upper lip, with diagnosis confirmed by pathology.
When to use this code
Use C00.3 when the provider documents primary cancer of the inner upper lip, including biopsy-confirmed squamous cell carcinoma or another malignant neoplasm at that site. Code it only when the anatomic location is clearly stated. If the note says upper lip without specifying the inner aspect, check documentation.
Do not use for
Do not use this code for lesions of the outer upper lip, commissure, or adjacent oral cavity sites. Also avoid it when the record describes a benign, premalignant, or metastatic lesion instead of a primary malignancy.
Coding tip
Match the exact subsite in the pathology or operative note; “upper lip” alone is not enough for C00.3.