ICD-10-CM > S00-T88 > T20-T25 > T20 > T20.4 > T20.42 T20.42 Corrosion of unspecified degree of lip(s) Non-Billable/Non-Specific Codes T20.42XA..., initial encounterT20.42XD..., subsequent encounterT20.42XS..., sequela