T58

Toxic effect of carbon monoxide

Header / non-billable

This code does not map to a risk-adjusting HCC in the loaded models.

Coding notes

Excludes 1 never coded together · Excludes 2 may co-exist

This code · T58
Includes

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

7th character

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

Valid 7th characters and their meanings
CharacterMeaning
Ainitial encounter
Dsubsequent encounter
Ssequela
Inherited from T51-T65Toxic effects of substances chiefly nonmedicinal as to source
Excludes 1

contact with and (suspected) exposure to toxic substances (Z77.-)

Use additional

code(s): for all associated manifestations of toxic effect, such as: respiratory conditions due to external agents (J60-J70) personal history of foreign body fully removed (Z87.821) to identify any retained foreign body, if applicable (Z18.-)

Note

When no intent is indicated code to accidental. Undetermined intent is only for use when there is specific documentation in the record that the intent of the toxic effect cannot be determined.

Inherited from chapter 19Injury, poisoning and certain other consequences of external causes
Excludes 2

birth trauma (P10-P15) obstetric trauma (O70-O71)

Use additional

code to identify any retained foreign body, if applicable (Z18.-)

Note

Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes. (T07-T88) Injury, poisoning and certain other consequences of external causes (T07-T88) (T20-T32) Burns and corrosions (T20-T32) Includes: burns (thermal) from electrical heating appliances burns (thermal) from electricity burns (thermal) from flame burns (thermal) from friction burns (thermal) from hot air and hot gases burns (thermal) from hot objects burns (thermal) from lightning burns (thermal) from radiation chemical burn [corrosion] (external) (internal) scalds Excludes2: erythema [dermatitis] ab igne (L59.0) radiation-related disorders of the skin and subcutaneous tissue (L55-L59) sunburn (L55.-)

Official Guidelines for T58

FY 2026 ›