ICD-10-CM > S00-T88 > T20-T25 > T25 > T25.4 > T25.42 > T25.422 T25.422 Corrosion of unspecified degree of left foot Non-Billable/Non-Specific Codes T25.422A..., initial encounterT25.422D..., subsequent encounterT25.422S..., sequela