ICD-10-CM > S00-T88 > T20-T25 > T22 > T22.4 > T22.41 > T22.419 T22.419 Corrosion of unspecified degree of unspecified forearm Non-Billable/Non-Specific Codes T22.419A..., initial encounterT22.419D..., subsequent encounterT22.419S..., sequela