ICD-10 Code D04.4 – Carcinoma in situ of skin of scalp and neck (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D04.4 – Carcinoma in situ of skin of scalp and neck
What it is
D04.4 identifies carcinoma in situ limited to the skin of the scalp and neck. The lesion is noninvasive, meaning abnormal cells are confined to the epidermis and have not spread into deeper tissue.
Clinical signs
Clinical features vary; refer to documentation. Commonly, you may see a persistent suspicious skin lesion on the scalp or neck, often requiring biopsy to confirm carcinoma in situ.
When to use this code
Use D04.4 when the record clearly documents carcinoma in situ involving skin of the scalp or neck. Apply it for confirmed noninvasive lesions at these sites, including pathology-supported diagnoses. If the note only says “skin cancer” or the site is unclear, check documentation before coding.
Do not use for
Do not use this code for invasive skin malignancies, benign lesions, or lesions on other body sites. If the documentation does not specify carcinoma in situ, do not assume D04.4.
Coding tip
Match the code to the exact anatomic site in the pathology or provider note, and verify that “in situ” is explicitly documented.