ICD-10-CM > S00-T88 > T20-T25 > T22 > T22.5 > T22.53 > T22.539 T22.539 Corrosion of first degree of unspecified upper arm Non-Billable/Non-Specific Codes T22.539A..., initial encounterT22.539D..., subsequent encounterT22.539S..., sequela