ICD-10-CM > S00-T88 > T33-T34 > T34 > T34.7 > T34.70 T34.70 Frostbite with tissue necrosis of unspecified knee and lower leg Non-Billable/Non-Specific Codes T34.70XA..., initial encounterT34.70XD..., subsequent encounterT34.70XS..., sequela