ICD-10-CM > S00-T88 > T33-T34 > T33 > T33.9 > T33.90 T33.90 Superficial frostbite of unspecified sites Non-Billable/Non-Specific Applicable To Superficial frostbite NOS Codes T33.90XA..., initial encounterT33.90XD..., subsequent encounterT33.90XS..., sequela