ICD-10-CM > S00-T88 > T20-T25 > T23 > T23.4 > T23.43 > T23.431 T23.431 Corrosion of unspecified degree of multiple right fingers (nail), not including thumb Non-Billable/Non-Specific Codes T23.431A..., initial encounterT23.431D..., subsequent encounterT23.431S..., sequela