Is T58 a billable ICD-10-CM code?

No. T58 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does T58 sit in the tabular list?

Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Toxic effects of substances chiefly nonmedicinal as to source (T51-T65).

T58

T58 — Toxic effect of carbon monoxide

Non-billable headerICD-10-CM

T58 is a non-billable header ICD-10-CM code for toxic effect of carbon monoxide. It cannot be billed on its own: choose one of the more specific child codes below. This code also requires a 7th character before it is complete.

This code requires a 7th character

The appropriate 7th character is to be added to each code from category T58

A: initial encounter
D: subsequent encounter
S: sequela

Includes

Conditions this code covers.

asphyxiation from carbon monoxide
toxic effect of carbon monoxide from all sources

Other codes that can never be billed with T58

These codes carry an Excludes1 note pointing at T58. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading T58 alone.

R09.0Asphyxia and hypoxemia
T71Asphyxiation

Risk adjustment

T58 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code to one of these instead T58

5 child codes. Green means billable.

Questions about T58

Is T58 a billable ICD-10-CM code?: No. T58 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does T58 sit in the tabular list?: Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Toxic effects of substances chiefly nonmedicinal as to source (T51-T65).