ICD-10-CM > S00-T88 > S20-S29 > S20 > S20.3 > S20.32 > S20.324 S20.324 Blister (nonthermal) of middle front wall of thorax Non-Billable/Non-Specific Codes S20.324A..., initial encounterS20.324D..., subsequent encounterS20.324S..., sequela