ICD-10-CM > S00-T88 > T20-T25 > T23 > T23.6 > T23.61 T23.61 Corrosion of second degree of thumb (nail) Non-Billable/Non-Specific Codes T23.611Corrosion of second degree of right thumb (nail)T23.611A..., initial encounterT23.611D..., subsequent encounterT23.611S..., sequelaT23.612Corrosion of second degree of left thumb (nail)T23.612A..., initial encounterT23.612D..., subsequent encounterT23.612S..., sequelaT23.619Corrosion of second degree of unspecified thumb (nail)T23.619A..., initial encounterT23.619D..., subsequent encounterT23.619S..., sequela