ICD-10-CM > S00-T88 > T51-T65 > T59 > T59.5 > T59.5X > T59.5X4 T59.5X4 Toxic effect of fluorine gas and hydrogen fluoride, undetermined Non-Billable/Non-Specific Codes T59.5X4A..., initial encounterT59.5X4D..., subsequent encounterT59.5X4S..., sequela