ICD-10-CM > S00-T88 > T20-T25 > T20 > T20.4 > T20.41 > T20.419 T20.419 Corrosion of unspecified degree of unspecified ear [any part, except ear drum] Non-Billable/Non-Specific Codes T20.419A..., initial encounterT20.419D..., subsequent encounterT20.419S..., sequela