T58.2X4AToxic effect of carbon monoxide from incomplete combustion of other domestic fuels, undetermined, initial encounter

T58.2X4A is the ICD-10-CM diagnosis code for toxic effect of carbon monoxide from incomplete combustion of other domestic fuels, undetermined, initial encounter. It belongs to category T58 (toxic effect of carbon monoxide), 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 billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

The 7th character "A" means initial encounter: use it while the patient is receiving active treatment for the condition.

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 917 (Poisoning and Toxic Effects of Drugs with MCC, relative weight 1.57) and DRG 918 (Poisoning and Toxic Effects of Drugs without MCC, relative weight 0.872), in MDC 21 (Injuries, Poisonings and Toxic Effects of Drugs), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

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

Before ICD-10, this condition was coded in ICD-9-CM as 986 (toxic effect of carbon monoxide) and E982.1 (poisoning by other carbon monoxide, undetermined whether accidentally or purposely inflicted).