ICD-10-CM > S00-T88 > T20-T25 > T21 > T21.7 > T21.71 T21.71 Corrosion of third degree of chest wall Non-Billable/Non-Specific Applicable To Corrosion of third degree of breast Codes T21.71XA..., initial encounterT21.71XD..., subsequent encounterT21.71XS..., sequela