ICD-10 Code K13.21 – Leukoplakia of oral mucosa, including tongue (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K13.21 – Leukoplakia of oral mucosa, including tongue
What it is
K13.21 identifies leukoplakia on the oral mucosa, including the tongue. Use it for a white oral patch or plaque that cannot be otherwise classified after evaluation.
Clinical signs
Findings usually include a persistent white lesion in the mouth or on the tongue that cannot be wiped away. Clinical features vary; refer to documentation.
When to use this code
Use K13.21 when the provider documents oral leukoplakia as the diagnosis, especially after examination of a non-removable white patch. It may also apply when the tongue is specifically involved. Do not code it for vague mouth irritation without documented leukoplakia.
Do not use for
Do not use this code for oral candidiasis, removable debris, or other clearly identified oral lesions. If the record does not confirm leukoplakia, check documentation.
Coding tip
Code only when the note clearly states leukoplakia and the lesion is not explained by another condition.