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