ICD-10-CM > S00-T88 > S90-S99 > S90 > S90.5 > S90.52 S90.52 Blister (nonthermal) of ankle Non-Billable/Non-Specific Codes S90.521Blister (nonthermal), right ankleS90.521A..., initial encounterS90.521D..., subsequent encounterS90.521S..., sequelaS90.522Blister (nonthermal), left ankleS90.522A..., initial encounterS90.522D..., subsequent encounterS90.522S..., sequelaS90.529Blister (nonthermal), unspecified ankleS90.529A..., initial encounterS90.529D..., subsequent encounterS90.529S..., sequela