ICD-10-CM > S00-T88 > T33-T34 > T34 > T34.9 > T34.90 T34.90 Frostbite with tissue necrosis of unspecified sites Non-Billable/Non-Specific Applicable To Frostbite with tissue necrosis NOS Codes T34.90XA..., initial encounterT34.90XD..., subsequent encounterT34.90XS..., sequela