| K13.0 | Diseases of lips | BILLABLE CODE |
| K13.1 | Cheek and lip biting | BILLABLE CODE |
| K13.2 | Leukoplakia and other disturbances of oral epithelium, including tongue | NON-BILLABLE CODE |
| K13.21 | Leukoplakia of oral mucosa, including tongue | BILLABLE CODE |
| K13.22 | Minimal keratinized residual ridge mucosa | BILLABLE CODE |
| K13.23 | Excessive keratinized residual ridge mucosa | BILLABLE CODE |
| K13.24 | Leukokeratosis nicotina palati | BILLABLE CODE |
| K13.29 | Other disturbances of oral epithelium, including tongue | BILLABLE CODE |
| K13.3 | Hairy leukoplakia | BILLABLE CODE |
| K13.4 | Granuloma and granuloma-like lesions of oral mucosa | BILLABLE CODE |
| K13.5 | Oral submucous fibrosis | BILLABLE CODE |
| K13.6 | Irritative hyperplasia of oral mucosa | BILLABLE CODE |
| K13.7 | Other and unspecified lesions of oral mucosa | NON-BILLABLE CODE |
| K13.70 | Unspecified lesions of oral mucosa | BILLABLE CODE |
| K13.79 | Other lesions of oral mucosa | BILLABLE CODE |
