ICD-10 Code D00.02 – Carcinoma in situ of buccal mucosa (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D00.02 – Carcinoma in situ of buccal mucosa
What it is
D00.02 identifies carcinoma in situ limited to the buccal mucosa, the inner lining of the cheek. The abnormal cells are confined to the epithelium and have not invaded deeper tissue.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include a persistent oral mucosal lesion, leukoplakia, erythema, ulceration, or a biopsy report confirming carcinoma in situ.
When to use this code
Use D00.02 when the provider documents carcinoma in situ specifically involving the buccal mucosa. Code it from pathology, operative, or specialist notes that clearly identify the site and in situ nature.
Do not assign it for vague oral dysplasia or for malignant oral cancer with invasion. If the record does not clearly specify buccal mucosa, check documentation before coding.
Do not use for
Do not use this code for invasive buccal cancer, unspecified oral cavity lesions, or premalignant changes without carcinoma in situ. Check documentation when the site is described only as “mouth” or “oral mucosa.”
Coding tip
Verify both the histology and the exact anatomic site before assigning D00.02.