ICD-10-CM > S00-T88 > S00-S09 > S00 > S00.5 > S00.52 > S00.522 S00.522 Blister (nonthermal) of oral cavity Non-Billable/Non-Specific Codes S00.522A..., initial encounterS00.522D..., subsequent encounterS00.522S..., sequela