ICD-10-CM > S00-T88 > S20-S29 > S20 > S20.3 > S20.32 > S20.321 S20.321 Blister (nonthermal) of right front wall of thorax Non-Billable/Non-Specific Codes S20.321A..., initial encounterS20.321D..., subsequent encounterS20.321S..., sequela