ICD-10-CM > S00-T88 > T20-T25 > T21 > T21.1 T21.1 Burn of first degree of trunk Non-Billable/Non-Specific Use Additional external cause code to identify the source, place and intent of the burn (X00-X19, X75-X77, X96-X98, Y92) Codes T21.10Burn of first degree of trunk, unspecified siteT21.10XA..., initial encounterT21.10XD..., subsequent encounterT21.10XS..., sequelaT21.11Burn of first degree of chest wallT21.11XA..., initial encounterT21.11XD..., subsequent encounterT21.11XS..., sequelaT21.12Burn of first degree of abdominal wallT21.12XA..., initial encounterT21.12XD..., subsequent encounterT21.12XS..., sequelaT21.13Burn of first degree of upper backT21.13XA..., initial encounterT21.13XD..., subsequent encounterT21.13XS..., sequelaT21.14Burn of first degree of lower backT21.14XA..., initial encounterT21.14XD..., subsequent encounterT21.14XS..., sequelaT21.15Burn of first degree of buttockT21.15XA..., initial encounterT21.15XD..., subsequent encounterT21.15XS..., sequelaT21.16Burn of first degree of male genital regionT21.16XA..., initial encounterT21.16XD..., subsequent encounterT21.16XS..., sequelaT21.17Burn of first degree of female genital regionT21.17XA..., initial encounterT21.17XD..., subsequent encounterT21.17XS..., sequelaT21.19Burn of first degree of other site of trunkT21.19XA..., initial encounterT21.19XD..., subsequent encounterT21.19XS..., sequela