T41.5X5A
Adverse effect of therapeutic gases, initial encounter
T41.5X5A (also written T415X5A) is a billable ICD-10-CM diagnosis code for adverse effect of therapeutic gases, initial encounter. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 126 codes in category T41 (Poisoning by, adverse effect of and underdosing of anesthetics and therapeutic gases). Its 7th character, A, means initial encounter. Its coding notes include a Code first instruction, a Use additional code instruction, 7 Excludes1 entries and 7 Excludes2 entries.
7th character
Category T41 requires a 7th character.
Guidelines tips
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
The 7th character depends on whether the patient is in active treatment, not on who sees the patient. An aftercare Z code is not used for injury aftercare.
T36-T65 codes already include the substance and the intent, so no additional external cause code is required. Do not code directly from the Table of Drugs and Chemicals.
Code first
If the underlying condition listed here is present and known, sequence it first.
Also from chapter/block level (7 notes)
Use additional code
Add the listed code as a secondary code, if known.
Also from chapter/block level (5 notes)
- code to identify any retained foreign body, if applicable (Z18.-)
Excludes1
Not coded here. The listed conditions generally should not be reported together.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (7 notes)
- birth trauma (P10-P15)
- obstetric trauma (O70-O71)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Hospice: not accepted as primary
Not accepted as the principal diagnosis on a hospice claim (bill types 081x and 082x). The Integrated OCE returns an edit for this code.
Reason: Supplementary or additional code, not allowed as principal diagnosis.
IPF Primary
IPF MS-DRG adjustment. A principal diagnosis of this code groups to one of these MS-DRGs. Which one depends on other facts of the stay, so the factor is a range:
| MS-DRG | Description | Factor |
|---|---|---|
| 917 | Poisoning and toxic effects of drugs w MCC | 1.19 |
| 918 | Poisoning and toxic effects of drugs w/out MCC | 1.12 |
Includes
Further defines or gives examples of the content of the category.
Also from chapter/block level (4 notes)
- adverse effect of correct substance properly administered
- poisoning by overdose of substance
- poisoning by wrong substance given or taken in error
- underdosing by (inadvertently) (deliberately) taking less substance than prescribed or instructed
Notes
Also from chapter/block level (3 notes)
- The drug giving rise to the adverse effect should be identified by use of codes from categories T36-T50 with fifth or sixth character 5.
- 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.