ICD-10-CM > S00-T88 > T20-T25 > T24 > T24.4 > T24.42 > T24.429 T24.429 Corrosion of unspecified degree of unspecified knee Non-Billable/Non-Specific Codes T24.429A..., initial encounterT24.429D..., subsequent encounterT24.429S..., sequela