ICD-10-CM > S00-T88 > T20-T25 > T23 > T23.3 > T23.31 > T23.319 T23.319 Burn of third degree of unspecified thumb (nail) Non-Billable/Non-Specific Codes T23.319A..., initial encounterT23.319D..., subsequent encounterT23.319S..., sequela