ICD-10-CM > S00-T88 > T51-T65 > T58 > T58.1 > T58.12 T58.12 Toxic effect of carbon monoxide from utility gas, intentional self-harm Non-Billable/Non-Specific Codes T58.12XA..., initial encounterT58.12XD..., subsequent encounterT58.12XS..., sequela