ICD-10-CM > S00-T88 > T20-T25 > T21 > T21.3 > T21.31 T21.31 Burn of third degree of chest wall Non-Billable/Non-Specific Applicable To Burn of third degree of breast Codes T21.31XA..., initial encounterT21.31XD..., subsequent encounterT21.31XS..., sequela