ICD-10-CM > S00-T88 > T33-T34 > T34 > T34.8 > T34.81 > T34.811 T34.811 Frostbite with tissue necrosis of right ankle Non-Billable/Non-Specific Codes T34.811A..., initial encounterT34.811D..., subsequent encounterT34.811S..., sequela