T43.611A
Poisoning by caffeine, accidental (unintentional), initial encounter
T43.611A (also written T43611A) is a billable ICD-10-CM diagnosis code for poisoning by caffeine, accidental (unintentional), initial encounter. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 354 codes in category T43 (Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified). Its 7th character, A, means initial encounter. Its coding notes include a Code first instruction, a Use additional code instruction, 2 Excludes1 entries and 13 Excludes2 entries.
7th character
Category T43 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.
Home Health Primary
Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Other clinical group.
Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026IPF 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 |
IPF Comorbidity
On the CMS IPF comorbidity list.
| Comorbidity category | Factor |
|---|---|
| Poisoning | 1.16 |
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
Inclusion terms
Conditions classified to this code.
- Poisoning by caffeine NOS
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.