ICD-10-CM > S00-T88 > S60-S69 > S60 > S60.4 > S60.42 > S60.421 S60.421 Blister (nonthermal) of left index finger Non-Billable/Non-Specific Codes S60.421A..., initial encounterS60.421D..., subsequent encounterS60.421S..., sequela