ICD-10-CM > S00-T88 > T20-T25 > T23 > T23.5 > T23.52 T23.52 Corrosion of first degree of single finger (nail) except thumb Non-Billable/Non-Specific Codes T23.521Corrosion of first degree of single right finger (nail) except thumbT23.521A..., initial encounterT23.521D..., subsequent encounterT23.521S..., sequelaT23.522Corrosion of first degree of single left finger (nail) except thumbT23.522A..., initial encounterT23.522D..., subsequent encounterT23.522S..., sequelaT23.529Corrosion of first degree of unspecified single finger (nail) except thumbT23.529A..., initial encounterT23.529D..., subsequent encounterT23.529S..., sequela