ICD-10 Code K13.70 – Unspecified lesions of oral mucosa (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K13.70 – Unspecified lesions of oral mucosa
What it is
K13.70 is used for a lesion or abnormal area on the oral mucosa when the specific cause or type is not documented. It is a nonspecific code for changes inside the mouth that need further clarification.
Clinical signs
Clinical features vary; refer to documentation. Findings may include a visible mucosal lesion, patch, ulcer, plaque, or other abnormal oral tissue change noted on exam.
When to use this code
Use K13.70 when the record describes an oral mucosal lesion but does not identify a more specific diagnosis. This may apply to lesions awaiting workup, incomplete documentation, or nonspecific oral findings. You should code the documented finding as written and avoid guessing the underlying cause.
Do not use for
Do not use this code when the provider documents a specific oral condition, such as a defined ulcer, leukoplakia, or another named disorder. Check documentation if the lesion is clearly linked to trauma, infection, or a separate diagnosis.
Coding tip
If the note names the lesion only as “oral mucosal lesion,” K13.70 is appropriate unless a more specific diagnosis is documented.