ICD-10 Code D04.0 – Carcinoma in situ of skin of lip (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D04.0 – Carcinoma in situ of skin of lip
What it is
D04.0 identifies carcinoma in situ limited to the skin of the lip. The abnormal cells are confined to the outer layer and have not invaded deeper tissue.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include a persistent scaly, crusted, or nonhealing lesion on the lip with biopsy confirmation of in situ disease.
When to use this code
Use D04.0 when the provider documents carcinoma in situ involving the skin of the lip, including biopsy-proven lesions confined to the epidermis. Code it for lesions described as in situ, Bowen disease, or equivalent wording if the lip skin is specified. Check documentation if the site is unclear or if invasion is reported.
Do not use for
Do not use this code for invasive lip cancer, dysplasia without carcinoma in situ, or lesions on the vermilion border unless the record clearly states skin of lip. Check documentation.
Coding tip
Confirm both the in situ diagnosis and the exact lip skin site before assigning D04.0.