ICD-10-CM > S00-T88 > T20-T25 > T23 > T23.5 > T23.54 > T23.542 T23.542 Corrosion of first degree of multiple left fingers (nail), including thumb Non-Billable/Non-Specific Codes T23.542A..., initial encounterT23.542D..., subsequent encounterT23.542S..., sequela