ICD-10-CM > S00-T88 > T20-T25 > T21 > T21.1 > T21.15 T21.15 Burn of first degree of buttock Non-Billable/Non-Specific Applicable To Burn of first degree of anus Codes T21.15XA..., initial encounterT21.15XD..., subsequent encounterT21.15XS..., sequela