T59.91XD — Toxic effect of unspecified gases, fumes and vapors, accidental (unintentional), subsequent encounter
Is T59.91XD billable?
Yes, but T59.91XD is an unspecified code. T59.91XD is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, T59.91XD is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting T59.91XD — the more specific alternatives are listed below.
More specific alternatives
- T59.0X1DToxic effect of nitrogen oxides, accidental (unintentional), subsequent encounter
- T59.1X1DToxic effect of sulfur dioxide, accidental (unintentional), subsequent encounter
- T59.2X1DToxic effect of formaldehyde, accidental (unintentional), subsequent encounter
- T59.3X1DToxic effect of lacrimogenic gas, accidental (unintentional), subsequent encounter
- T59.4X1DToxic effect of chlorine gas, accidental (unintentional), subsequent encounter
- T59.5X1DToxic effect of fluorine gas and hydrogen fluoride, accidental (unintentional), subsequent encounter
- T59.6X1DToxic effect of hydrogen sulfide, accidental (unintentional), subsequent encounter
- T59.7X1DToxic effect of carbon dioxide, accidental (unintentional), subsequent encounter
T59.91XD at a glance
| Code | T59.91XD |
|---|---|
| Description | Toxic effect of unspecified gases, fumes and vapors, accidental (unintentional), subsequent encounter |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
| 7th character "D" | subsequent encounter |
What does the 7th character "D" mean in T59.91XD?
In T59.91XD, the 7th character D means subsequent encounter. The 7th character is required for T59.91XD to be a valid, complete code.
Same condition, different episode of care — switch the 7th character:
Which MS-DRGs does T59.91XD group to?
T59.91XD sits in MDC 23 and helps define the logic of 2 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 949Aftercare with CC/MCCmedical
- 950Aftercare without CC/MCCmedical
How is T59.91XD listed in the Alphabetic Index?
The Alphabetic Index lists these routes under T59.9, the nearest indexed parent of T59.91XD. Use them to find the family, then select the specific code.
- Vapor asphyxia or suffocation
- Conflagration › asphyxia
- Effect, adverse › gases, fumes, or vapors
- Inhalation › gases, fumes, or vapors
- Inhalation › steam
Excludes1 — never code together — inherited from T51-T65
The conditions below can never be reported together with T59.91XD on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- contact with and (suspected) exposure to toxic substances (Z77.-)
Excludes1 — never code together — inherited from T59
The conditions below can never be reported together with T59.91XD on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
- chlorofluorocarbons (T53.5)
Use additional code — inherited from Chapter 19
Report an additional code alongside T59.91XD to fully describe the condition. T59.91XD is sequenced first.
- code to identify any retained foreign body, if applicable (Z18.-)
Use additional code — inherited from T51-T65
Report an additional code alongside T59.91XD to fully describe the condition. T59.91XD is sequenced first.
Excludes2 — not included here — inherited from Chapter 19
The conditions below are not part of T59.91XD, but a patient may have both at the same time. When documentation supports it, T59.91XD and the excluded code may both be reported.
How long has T59.91XD existed?
T59.91XD has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.