2026 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 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 917 through 918. 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.
Code Identity
Code Classification
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 2026, published by CMS and the National Center for Health Statistics.
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.Cytochrome P-450 CYP1A2
a cytochrome p450 enzyme subtype that has specificity for relatively planar heteroaromatic small molecules, such as caffeine and acetaminophen.
Table of Drugs and ChemicalsClinical
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
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, 2025 through September 30, 2026.
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 917, 918, with relative weights from 0.8571 to 1.5684 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of T43.611A?
Under the General Equivalence Mappings, poisoning by caffeine, accidental (unintentional), initial encounter converts to ICD-9-CM 969.71 (poisoning by caffeine) and E854.2 (acc poisn-psychstimulant). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
