ICD-10-CM > S00-T88 > T20-T25 > T25 > T25.4 > T25.42 T25.42 Corrosion of unspecified degree of foot Non-Billable/Non-Specific Type 2 Excludes corrosion of unspecified degree of toe(s) (nail) (T25.43-) Codes T25.421Corrosion of unspecified degree of right footT25.421A..., initial encounterT25.421D..., subsequent encounterT25.421S..., sequelaT25.422Corrosion of unspecified degree of left footT25.422A..., initial encounterT25.422D..., subsequent encounterT25.422S..., sequelaT25.429Corrosion of unspecified degree of unspecified footT25.429A..., initial encounterT25.429D..., subsequent encounterT25.429S..., sequela