ICD-10 Code C06.8 – Malignant neoplasm of overlapping sites of other and unspecified parts of mouth (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C06.8 – Malignant neoplasm of overlapping sites of other and unspecified parts of mouth
What it is
C06.8 identifies a malignant tumor of the mouth that spans overlapping sites in the oral cavity, or an oral cancer whose exact subsite is not otherwise specified. Use it when the lesion cannot be assigned to a single, more specific mouth location.
Clinical signs
Findings may include a persistent oral mass, ulcer, pain, bleeding, dysphagia, or loose teeth. Clinical features vary; refer to documentation and pathology when available.
When to use this code
Use C06.8 when the provider documents oral cancer involving overlapping parts of the mouth, such as a lesion crossing adjacent oral subsites. It also fits when the record states a malignant neoplasm of the mouth but does not name a more specific site. Verify the exact anatomic description before coding.
Do not use for
Do not use this code for benign oral lesions, dysplasia, or cancers clearly documented in a single specific mouth subsite. Check documentation if the tumor site is actually lip, tongue, gingiva, or another coded location.
Coding tip
Code the most specific oral subsite documented; use C06.8 only when overlap or nonspecific location is clearly stated.