ICD-10-CM > S00-T88 > T36-T50 > T50 > T50.9 > T50.99 > T50.991 T50.991 Poisoning by other drugs, medicaments and biological substances, accidental (unintentional) Non-Billable/Non-Specific Codes T50.991A..., initial encounterT50.991D..., subsequent encounterT50.991S..., sequela