ICD-10-CM > S00-T88 > T20-T25 > T22 > T22.6 > T22.63 > T22.639 T22.639 Corrosion of second degree of unspecified upper arm Non-Billable/Non-Specific Codes T22.639A..., initial encounterT22.639D..., subsequent encounterT22.639S..., sequela