ICD-10-CM > S00-T88 > T20-T25 > T23 > T23.6 > T23.64 > T23.641 T23.641 Corrosion of second degree of multiple right fingers (nail), including thumb Non-Billable/Non-Specific Codes T23.641A..., initial encounterT23.641D..., subsequent encounterT23.641S..., sequela