ICD-10-CM > S00-T88 > S80-S89 > S80 > S80.2 > S80.22 S80.22 Blister (nonthermal) of knee Non-Billable/Non-Specific Codes S80.221Blister (nonthermal), right kneeS80.221A..., initial encounterS80.221D..., subsequent encounterS80.221S..., sequelaS80.222Blister (nonthermal), left kneeS80.222A..., initial encounterS80.222D..., subsequent encounterS80.222S..., sequelaS80.229Blister (nonthermal), unspecified kneeS80.229A..., initial encounterS80.229D..., subsequent encounterS80.229S..., sequela