ICD-10-CM > S00-T88 > T20-T25 > T20 > T20.4 T20.4 Corrosion of unspecified degree of head, face, and neck Non-Billable/Non-Specific Code First (T51-T65) to identify chemical and intent Use Additional external cause code to identify place (Y92) Codes T20.40Corrosion of unspecified degree of head, face, and neck, unspecified siteT20.40XA..., initial encounterT20.40XD..., subsequent encounterT20.40XS..., sequelaT20.41Corrosion of unspecified degree of ear [any part, except ear drum]T20.411Corrosion of unspecified degree of right ear [any part, except ear drum]T20.411A..., initial encounterT20.411D..., subsequent encounterT20.411S..., sequelaT20.412Corrosion of unspecified degree of left ear [any part, except ear drum]T20.412A..., initial encounterT20.412D..., subsequent encounterT20.412S..., sequelaT20.419Corrosion of unspecified degree of unspecified ear [any part, except ear drum]T20.419A..., initial encounterT20.419D..., subsequent encounterT20.419S..., sequelaT20.42Corrosion of unspecified degree of lip(s)T20.42XA..., initial encounterT20.42XD..., subsequent encounterT20.42XS..., sequelaT20.43Corrosion of unspecified degree of chinT20.43XA..., initial encounterT20.43XD..., subsequent encounterT20.43XS..., sequelaT20.44Corrosion of unspecified degree of nose (septum)T20.44XA..., initial encounterT20.44XD..., subsequent encounterT20.44XS..., sequelaT20.45Corrosion of unspecified degree of scalp [any part]T20.45XA..., initial encounterT20.45XD..., subsequent encounterT20.45XS..., sequelaT20.46Corrosion of unspecified degree of forehead and cheekT20.46XA..., initial encounterT20.46XD..., subsequent encounterT20.46XS..., sequelaT20.47Corrosion of unspecified degree of neckT20.47XA..., initial encounterT20.47XD..., subsequent encounterT20.47XS..., sequelaT20.49Corrosion of unspecified degree of multiple sites of head, face, and neckT20.49XA..., initial encounterT20.49XD..., subsequent encounterT20.49XS..., sequela