ICD-10-CM > S00-T88 > T51-T65 > T58 > T58.1 > T58.11 T58.11 Toxic effect of carbon monoxide from utility gas, accidental (unintentional) Non-Billable/Non-Specific Codes T58.11XA..., initial encounterT58.11XD..., subsequent encounterT58.11XS..., sequela