ICD-10 Code D00.06 – Carcinoma in situ of floor of mouth (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D00.06 – Carcinoma in situ of floor of mouth
What it is
D00.06 identifies carcinoma in situ confined to the floor of the mouth. The abnormal cells are present in the lining tissue but have not invaded deeper structures.
Clinical signs
Findings may include a persistent oral mucosal lesion, such as a red or white patch, ulceration, or thickened area on the floor of the mouth. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents carcinoma in situ specifically located on the floor of the mouth. It fits pathology-confirmed or clearly documented in situ disease without evidence of invasion. Check documentation if the site or depth of involvement is unclear.
Do not use for
Do not use D00.06 for invasive oral cancer, dysplasia without carcinoma in situ, or lesions in other oral sites. If the record does not specify the floor of mouth, check documentation.
Coding tip
Verify both the anatomic site and the in situ wording before assigning D00.06.