ICD-10 Code D04.1 – Carcinoma in situ of skin of eyelid, including canthus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D04.1 – Carcinoma in situ of skin of eyelid, including canthus
What it is
D04.1 identifies carcinoma in situ limited to the skin of the eyelid or canthus. The abnormal cells have not invaded deeper tissue, so the diagnosis remains noninvasive.
Clinical signs
Clinical features vary; refer to documentation. Lesions may appear as a persistent scaly, crusted, or nonhealing change on the eyelid or canthal skin, but confirmation depends on the documented pathology.
When to use this code
Use D04.1 when the provider documents carcinoma in situ on the eyelid or canthus skin, including biopsy-confirmed noninvasive disease. Apply it for lesions specifically described as in situ and limited to that site. If the note only says “skin cancer” or the exact location is unclear, check documentation.
Do not use for
Do not use this code for invasive eyelid malignancy, benign eyelid lesions, or uncertain skin changes without a documented carcinoma in situ diagnosis. Check documentation if the pathology or site is not specific.
Coding tip
Match the code to the exact eyelid or canthus site stated in the pathology or assessment, and confirm that “in situ” is explicitly documented.