2027 ICD-10-CM Diagnosis Code T43.611APoisoning by caffeine, accidental (unintentional), initial encounter
T43.611A is a billable ICD-10-CM diagnosis code for poisoning by caffeine, accidental (unintentional), initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 917 through 918. Coders also document this condition as accidental caffeine overdose. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under External cause codes: intent of injury, accidental/unintentional; External cause codes: poisoning by drug; and Poisoning by drugs, initial encounter.
For Medicare Advantage risk adjustment, T43.611A maps to CMS-HCC Category 137 (Drug Use Disorder, Moderate/Severe, or Drug Use with Non-Psychotic Complications) under the V28 model, adding a risk factor of about 0.424 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
T43.611A maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Accidental caffeine overdose
- Accidental phosphodiesterase inhibitor overdose
- Accidental phosphodiesterase inhibitor poisoning
- Accidental poisoning by caffeine
- Caffeine overdose
- Poisoning by caffeine
- Xanthine and/or xanthine derivative overdose
Coding GuidelinesGuidance
When coding a poisoning or reaction to the improper use of a medication (e.g., overdose, wrong substance given or taken in error, wrong route of administration), first assign the appropriate code from categories T36-T50. The poisoning codes have an associated intent as their 5th or 6th character (accidental, intentional self-harm, assault and undetermined). If the intent of the poisoning is unknown or unspecified, code the intent as accidental intent. The undetermined intent is only for use if the documentation in the record specifies that the intent cannot be determined. Use additional code(s) for all manifestations of poisonings.
The appropriate 7th character is to be added to each code from block Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified (T43). 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 2027, published by CMS and the National Center for Health Statistics.
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to T43.611A: its own notes plus those printed at T43.6, T43, block T36-T50, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.
Includes
Further defines, or gives examples of, the content of the category.
- 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
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- poisoning by, adverse effect of and underdosing of cocaine (T40.5-)
- toxic reaction to local anesthesia in pregnancy (O29.3-)
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Code First
The underlying condition named in the note is sequenced before this code.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify any retained foreign body, if applicable (Z18.-)
Notes
General instructions on how these codes are used.
- 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.
7th Character
Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.
- The appropriate 7th character is to be added to each code from category T43
- Ainitial encounter this code
- Dsubsequent encounter
- Ssequela
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Caffeine
a methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. it also relaxes smooth muscle, stimulates cardiac muscle, stimulates diuresis, and appears to be useful in the treatment of some types of headache. several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. among the most important are inhibition of cyclic nucleotide phosphodiesterases, antagonism of adenosine receptors, and modulation of intracellular calcium handling.
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
Caffeine
Caffeine is a bitter substance that occurs naturally in more than 60 plants including:
The full article covers:
- What is caffeine?
- What are caffeine's effects on the body?
- What are the side effects from too much caffeine?
- What are energy drinks, and why can they be a problem?
- Who should avoid or limit caffeine?
- What is caffeine withdrawal?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert T43.611A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T43.611AOverview
What is the ICD-10 code for poisoning by caffeine, accidental (unintentional), initial encounter?
The ICD-10-CM code for poisoning by caffeine, accidental (unintentional), initial encounter is T43.611A (sometimes written as T43611A). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is T43.611A (Poisoning by caffeine, accidental (unintentional)) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report poisoning by caffeine, accidental (unintentional), initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What does the 7th character A in T43.611A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for poisoning by caffeine, accidental (unintentional), such as an emergency visit or first evaluation.
What MS-DRG does T43.611A group to?
When poisoning by caffeine, accidental (unintentional), initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 918, 917, with relative weights from 0.8716 to 1.5698 depending on complications. Higher weights mean higher Medicare reimbursement.
Can T43.611A be reported with a code from T40.5?
Not as a rule. The Excludes1 note at T43.6, which applies to T43.611A, lists "poisoning by, adverse effect of and underdosing of cocaine (T40.5-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What HCC is T43.611A?
T43.611A (poisoning by caffeine, accidental (unintentional), initial encounter) maps to CMS-HCC Category 137 (Drug Use Disorder, Moderate/Severe, or Drug Use with Non-Psychotic Complications), commonly written as HCC 137, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 55 under the retired V24 model. It also maps in the ESRD (V24) model. It does not map to any RxHCC in the Part D prescription drug model.
Does T43.611A risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, T43.611A adds a risk adjustment factor of about 0.424 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.297 to 0.502 depending on the payment segment). A more severe related category (HCC 135 and HCC 136) supersedes it when both are reported. See the full factor table on the HCC 137 category page.
