T58UpcomingCategory · further specificity required

Toxic effect of carbon monoxide

Code-level instructions

A — initial encounter

D — subsequent encounter

S — sequela

Chapters 19 · Inherited instructions

Use additional code

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

T51-T65 · Inherited instructions

Use additional code

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.-)

Excludes 1

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

Excludes 2 · 2

Chapters 19 · Injury, poisoning and certain other consequences of external causes (S00-T88)

Excludes 2

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

More specific codes

T58.0Toxic effect of carbon monoxide from motor vehicle exhaust T58.1Toxic effect of carbon monoxide from utility gas T58.2Toxic effect of carbon monoxide from incomplete combustion of other domestic fuels T58.8Toxic effect of carbon monoxide from other source T58.9Toxic effect of carbon monoxide from unspecified source

Claims & coverage

When ICD-10-CM is required

For US diagnosis claims covered by HIPAA, ICD-10-CM is required from October 1, 2015.

Use the service date for outpatient/professional claims and the discharge date for hospital inpatient claims. Earlier encounters use ICD-9-CM; each individual code must also be valid for the applicable date.

Official coding guidelines → · CMS ↗

First observed · 2015-10-01

Code history

Latest recorded change · FY2025 · 04-01

ChangedUnchanged

FY2025 · 04-01

Effective from 2025-04-01

Inherited rules changed

Toxic effect of carbon monoxide

Category — select a more specific code

CDC/NCHS · FY2025 · 04-01

All editions (19)

All editions	Effective from	Code history
FY2016	2015-10-01	First observed
FY2017	2016-10-01	No tabular change
FY2018	2017-10-01	No tabular change
FY2019	2018-10-01	No tabular change
FY2020	2019-10-01	No tabular change
FY2020 · April	2020-04-01	No tabular change
FY2021	2020-10-01	No tabular change
FY2021 · 01-01	2021-01-01	No tabular change
FY2022	2021-10-01	No tabular change
FY2022 · 04-01	2022-04-01	No tabular change
FY2023	2022-10-01	No tabular change
FY2023 · 04-01	2023-04-01	No tabular change
FY2024	2023-10-01	No tabular change
FY2024 · 04-01	2024-04-01	No tabular change
FY2025	2024-10-01	No tabular change
FY2025 · 04-01	2025-04-01	Inherited rules changed
FY2026	2025-10-01	No tabular change
FY2026 · April	2026-04-01	No tabular change
FY2027	2026-10-01	No tabular change

Code-level instructions

Includes

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

Seventh character

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

A — initial encounter

D — subsequent encounter

S — sequela

Inherited instructions

Chapters 19 · Injury, poisoning and certain other consequences of external causes (S00-T88)

Excludes 2

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

Use additional code

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.

T51-T65 · Toxic effects of substances chiefly nonmedicinal as to source (T51-T65)

Excludes 1

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

Use additional code

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.

More specific codes

T58.0Toxic effect of carbon monoxide from motor vehicle exhaustCategory · further specificity required T58.1Toxic effect of carbon monoxide from utility gasCategory · further specificity required T58.2Toxic effect of carbon monoxide from incomplete combustion of other domestic fuelsCategory · further specificity required T58.8Toxic effect of carbon monoxide from other sourceCategory · further specificity required T58.9Toxic effect of carbon monoxide from unspecified sourceCategory · further specificity required

Related codes

Official titles and instructions are preserved in their source language. Official sources ↗

References from other codes (2)

R09.0 · Asphyxia and hypoxemia

Excludes 1 · asphyxia due to carbon monoxide (T58.-)

T71 · Asphyxiation

Excludes 1 · asphyxia from carbon monoxide (T58.-)

T58UpcomingCategory · further specificity required

Toxic effect of carbon monoxide

Code-level instructions

A — initial encounter

D — subsequent encounter

S — sequela

Chapters 19 · Inherited instructions

Use additional code

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

T51-T65 · Inherited instructions

Use additional code

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.-)

Excludes 1

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

Excludes 2 · 2

Chapters 19 · Injury, poisoning and certain other consequences of external causes (S00-T88)

Excludes 2

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

More specific codes

Claims & coverage

When ICD-10-CM is required

For US diagnosis claims covered by HIPAA, ICD-10-CM is required from October 1, 2015.

Official coding guidelines → · CMS ↗

First observed · 2015-10-01

Code history

Latest recorded change · FY2025 · 04-01

ChangedUnchanged

FY2025 · 04-01

Effective from 2025-04-01

Inherited rules changed

Toxic effect of carbon monoxide

Category — select a more specific code

CDC/NCHS · FY2025 · 04-01

All editions (19)

All editions	Effective from	Code history
FY2016	2015-10-01	First observed
FY2017	2016-10-01	No tabular change
FY2018	2017-10-01	No tabular change
FY2019	2018-10-01	No tabular change
FY2020	2019-10-01	No tabular change
FY2020 · April	2020-04-01	No tabular change
FY2021	2020-10-01	No tabular change
FY2021 · 01-01	2021-01-01	No tabular change
FY2022	2021-10-01	No tabular change
FY2022 · 04-01	2022-04-01	No tabular change
FY2023	2022-10-01	No tabular change
FY2023 · 04-01	2023-04-01	No tabular change
FY2024	2023-10-01	No tabular change
FY2024 · 04-01	2024-04-01	No tabular change
FY2025	2024-10-01	No tabular change
FY2025 · 04-01	2025-04-01	Inherited rules changed
FY2026	2025-10-01	No tabular change
FY2026 · April	2026-04-01	No tabular change
FY2027	2026-10-01	No tabular change

Code-level instructions

Includes

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

Seventh character

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

A — initial encounter

D — subsequent encounter

S — sequela

Inherited instructions

Chapters 19 · Injury, poisoning and certain other consequences of external causes (S00-T88)

Excludes 2

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

Use additional code

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.

T51-T65 · Toxic effects of substances chiefly nonmedicinal as to source (T51-T65)

Excludes 1

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

Use additional code

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.

More specific codes

Related codes

Official titles and instructions are preserved in their source language. Official sources ↗

References from other codes (2)

R09.0 · Asphyxia and hypoxemia

Excludes 1 · asphyxia due to carbon monoxide (T58.-)

T71 · Asphyxiation

Excludes 1 · asphyxia from carbon monoxide (T58.-)