FY2027 ICD-10-CM reference
T59: Toxic effect of other gases, fumes and vapors
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Toxic effect of other gases, fumes and vapors. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Nonbillable heading. Verified against the official FY2027 order file.
More specific FY2027 codes
- T59.0: Toxic effect of nitrogen oxidesNonbillable heading
- T59.1: Toxic effect of sulfur dioxideNonbillable heading
- T59.2: Toxic effect of formaldehydeNonbillable heading
- T59.3: Toxic effect of lacrimogenic gasNonbillable heading
- T59.4: Toxic effect of chlorine gasNonbillable heading
- T59.5: Toxic effect of fluorine gas and hydrogen fluorideNonbillable heading
- T59.6: Toxic effect of hydrogen sulfideNonbillable heading
- T59.7: Toxic effect of carbon dioxideNonbillable heading
- T59.8: Toxic effect of other specified gases, fumes and vaporsNonbillable heading
- T59.9: Toxic effect of unspecified gases, fumes and vaporsNonbillable heading
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Instructional 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
Source: S00-T88 (chapter, inherited).
Instructional note
code to identify any retained foreign body, if applicable (Z18.-)
Source: S00-T88 (chapter, inherited).
Excludes2
birth trauma (P10-P15)
Source: S00-T88 (chapter, inherited).
Excludes2
obstetric trauma (O70-O71)
Source: S00-T88 (chapter, inherited).
Instructional note
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.
Source: S00-T88 (chapter, inherited).
Instructional 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.
Source: T51-T65 (section, inherited).
Instructional note
code(s):
Source: T51-T65 (section, inherited).
Instructional note
for all associated manifestations of toxic effect, such as: respiratory conditions due to external agents (J60-J70)
Source: T51-T65 (section, inherited).
Instructional note
personal history of foreign body fully removed (Z87.821)
Source: T51-T65 (section, inherited).
Instructional note
to identify any retained foreign body, if applicable (Z18.-)
Source: T51-T65 (section, inherited).
Excludes1
contact with and (suspected) exposure to toxic substances (Z77.-)
Source: T51-T65 (section, inherited).
Includes
aerosol propellants
Source: T59 (category, direct).
Excludes1
chlorofluorocarbons (T53.5)
Source: T59 (category, direct).
Seventh-character instruction
The appropriate 7th character is to be added to each code from category T59
Source: T59 (category, direct).
Instructional note
initial encounter
Source: T59 (category, direct).
Instructional note
subsequent encounter
Source: T59 (category, direct).
Instructional note
sequela
Source: T59 (category, direct).
Seventh-character definitions
- A: initial encounter
- D: subsequent encounter
- S: sequela
Compare the FY2027 additions, removals and billable-status changes
What does T59 mean in FY2027?
The official ICD-10-CM descriptor is Toxic effect of other gases, fumes and vapors. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is T59 billable in FY2027?
The FY2027 order file marks T59 as a nonbillable heading. Select a complete billable child code.
Does T59 map to an HCC?
Risk-model mapping is not applicable to this nonbillable heading. Check a complete billable child code.
Source: CMS FY2027 ICD-10-CM order file. Payment model: CMS CY 2027 Rate Announcement. Read the FY2027 Official Guidelines.
Review the FY2026 April edition