ICD-10-CM > S00-T88 > T20-T25 > T24 > T24.4 > T24.42 > T24.422 T24.422 Corrosion of unspecified degree of left knee Non-Billable/Non-Specific Codes T24.422A..., initial encounterT24.422D..., subsequent encounterT24.422S..., sequela