2026 ICD-10-CM Diagnosis Code T58.01XSToxic effect of carbon monoxide from motor vehicle exhaust, accidental (unintentional), sequela
T58.01XS is a billable ICD-10-CM diagnosis code for toxic effect of carbon monoxide from motor vehicle exhaust, accidental (unintentional), sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Poisoning/toxic effect/adverse effects/underdosing, sequela.
Code Identity
Code Classification
Present on Admission (POA)Billing
T58.01XS is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Accidental poisoning by exhaust gas from gas engine
- Accidental poisoning by exhaust gas from motor pump
- Accidental poisoning by exhaust gas from stationary farm tractor
- Accidental poisoning by exhaust gas from stationary motor vehicle
- Accidental poisoning by motor vehicle exhaust gas
- Carbon monoxide poisoning from motor vehicle exhaust
- Noncollision motor vehicle traffic accident involving accidental poisoning from exhaust gas generated by motor vehicle while in motion
- Noncollision motor vehicle traffic accident involving accidental poisoning from exhaust gas generated by motor vehicle while in motion, driver of motor vehicle injured
- Noncollision motor vehicle traffic accident involving accidental poisoning from exhaust gas generated by motor vehicle while in motion, motor cyclist injured
- Noncollision motor vehicle traffic accident involving accidental poisoning from exhaust gas generated by motor vehicle while in motion, occupant of tram injured
- Noncollision motor vehicle traffic accident involving accidental poisoning from exhaust gas generated by motor vehicle while in motion, passenger of motor vehicle injured
- Noncollision motor vehicle traffic accident involving accidental poisoning from exhaust gas generated by motor vehicle while in motion, passenger on motor cycle injured
- Noncollision motor vehicle traffic accident involving accidental poisoning from exhaust gas generated by motor vehicle while in motion, pedal cyclist injured
- Noncollision motor vehicle traffic accident involving accidental poisoning from exhaust gas generated by motor vehicle while in motion, pedestrian injured
- Noncollision motor vehicle traffic accident involving accidental poisoning from exhaust gas generated by motor vehicle while in motion, rider of animal or occupant of animal-drawn vehicle injured
- Poisoning by carbon monoxide from aircraft while in transit, without accident to aircraft
- Poisoning by carbon monoxide from aircraft while in transit, without accident to aircraft, member of crew of commercial aircraft in surface to surface transport injured
- Poisoning by carbon monoxide from aircraft while in transit, without accident to aircraft, occupant of commercial aircraft in surface to air transport injured
- Poisoning by carbon monoxide from aircraft while in transit, without accident to aircraft, occupant of military aircraft injured
- Poisoning by carbon monoxide from aircraft while in transit, without accident to aircraft, parachutist injured
- Poisoning by exhaust gas in aircraft
- Poisoning by exhaust gases on board watercraft
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Toxic effect of carbon monoxide (T58). Use the following options for the applicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Table of Drugs and ChemicalsClinical
Substances in the Table of Drugs and Chemicals that reference this code family. Always confirm in the Tabular List before coding.
Patient EducationClinical
Carbon Monoxide Poisoning
Carbon monoxide (CO) is a gas that has no odor or color. But it is very dangerous. It can cause sudden illness and death. CO is found in combustion fumes, such as those made by cars and trucks, lanterns, stoves, gas ranges and heating systems. CO from these fumes can build up in places that don't have a good flow of fresh air.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert T58.01XS to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T58.01XSOverview
Is T58.01XS a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report toxic effect of carbon monoxide from motor vehicle exhaust, accidental (unintentional), sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T58.01XS mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the toxic effect of carbon monoxide from motor vehicle exhaust, accidental (unintentional) itself has resolved, not the original event.
What MS-DRG does T58.01XS group to?
When toxic effect of carbon monoxide from motor vehicle exhaust, accidental (unintentional), sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.
Is T58.01XS exempt from POA reporting?
Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for toxic effect of carbon monoxide from motor vehicle exhaust, accidental (unintentional), sequela on inpatient claims.
What is the ICD-9 equivalent of T58.01XS?
Under the General Equivalence Mappings, toxic effect of carbon monoxide from motor vehicle exhaust, accidental (unintentional), sequela converts to ICD-9-CM 909.1 (late eff nonmed substanc). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
