ICD-10-CM > S00-T88 > T51-T65 > T65 > T65.9 > T65.91 T65.91 Toxic effect of unspecified substance, accidental (unintentional) Non-Billable/Non-Specific Applicable To Poisoning NOS Codes T65.91XA..., initial encounterT65.91XD..., subsequent encounterT65.91XS..., sequela