ICD-10 Code C44.00 – Unspecified malignant neoplasm of skin of lip (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C44.00 – Unspecified malignant neoplasm of skin of lip
What it is
This code identifies a malignant skin tumor on the lip when the record does not specify the exact histology. Use it for a cancer documented as arising in the skin of the lip, not the inner mucosa.
Clinical signs
Clinical features vary; refer to documentation. Commonly, the lesion is a persistent lip growth, ulcer, crusted area, or nonhealing sore that prompts biopsy or specialist evaluation.
When to use this code
Use C44.00 when the provider documents a malignant neoplasm of the skin of the lip but does not identify basal cell, squamous cell, or another specific type. It also fits when laterality is not relevant and the note clearly places the tumor on the lip skin. If the chart only says “lip cancer,” check documentation before coding.
Do not use for
Do not use this code for benign lip lesions, premalignant conditions, or cancers of the oral mucosa. If the pathology or note specifies a different skin cancer type, code that diagnosis instead.
Coding tip
Confirm whether the lesion is on the external lip skin versus the vermilion border or oral cavity before assigning C44.00.