ICD-10-CM > S00-T88 > T20-T25 > T23 > T23.5 > T23.53 > T23.539 T23.539 Corrosion of first degree of unspecified multiple fingers (nail), not including thumb Non-Billable/Non-Specific Codes T23.539A..., initial encounterT23.539D..., subsequent encounterT23.539S..., sequela