ICD-10 Code K13 – Other diseases of lip and oral mucosa (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K13 – Other diseases of lip and oral mucosa
What it is
K13 is a broad ICD-10-CM category for disorders of the lips and oral mucosa that do not fit a more specific code. Use it when the record documents an oral or lip condition, but the exact diagnosis is not otherwise classified.
Clinical signs
Clinical features vary; refer to documentation. Findings may include visible lip or oral mucosal changes, irritation, ulceration, swelling, or other nonspecific lesions noted on exam.
When to use this code
Use K13 when the clinician documents a disease of the lip or oral mucosa and no more specific ICD-10-CM code applies. It is appropriate for nonspecific or otherwise classified oral mucosal disorders. Check documentation if the note names a distinct diagnosis that has its own code.
Do not use for
Do not use K13 for clearly identified conditions with separate codes, such as infections, neoplasms, or traumatic injuries of the mouth. If the chart specifies a different diagnosis, code that condition instead.
Coding tip
Choose the most specific oral or lip diagnosis documented; use K13 only when the record supports a nonspecific “other” disease.