T58Toxic effect of carbon monoxide

T58 is the ICD-10-CM diagnosis code for toxic effect of carbon monoxide. It belongs to block T51-T65 (toxic effects of substances chiefly nonmedicinal as to source) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 5 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: T58.0 (from motor vehicle exhaust), T58.1 (from utility gas), T58.2 (from incomplete combustion of other domestic fuels), T58.8 (from other source) and T58.9 (from unspecified source).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.