ICD-10-CM > S00-T88 > T20-T25 > T25 > T25.4 > T25.43 > T25.431 T25.431 Corrosion of unspecified degree of right toe(s) (nail) Non-Billable/Non-Specific Codes T25.431A..., initial encounterT25.431D..., subsequent encounterT25.431S..., sequela