2026 ICD-10-CM Diagnosis Code T43Poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified
T43 is a non-billable ICD-10-CM category code for poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified, so it cannot be submitted on claims. Use a more specific code from this category instead, such as T43.011A, T43.011D, T43.011S, and T43.012A.
Code Identity
Code Classification
Specific Coding for Psychotropic drugs, not elsewhere classifiedOverview
Non-specific codes like T43 require more characters. Use one of these billable codes instead:
T43.0 for Poisoning by, adverse effect of and underdosing of tricyclic and tetracyclic antidepressants
T43.01 for Poisoning by, adverse effect of and underdosing of tricyclic antidepressants
T43.02 for Poisoning by, adverse effect of and underdosing of tetracyclic antidepressants
T43.1 for Poisoning by, adverse effect of and underdosing of monoamine-oxidase-inhibitor antidepressants
T43.1X for Poisoning by, adverse effect of and underdosing of monoamine-oxidase-inhibitor antidepressants
T43.2 for Poisoning by, adverse effect of and underdosing of other and unspecified antidepressants
T43.20 for Poisoning by, adverse effect of and underdosing of unspecified antidepressants
T43.21 for Poisoning by, adverse effect of and underdosing of selective serotonin and norepinephrine reuptake inhibitors
T43.22 for Poisoning by, adverse effect of and underdosing of selective serotonin reuptake inhibitors
T43.29 for Poisoning by, adverse effect of and underdosing of other antidepressants
T43.3 for Poisoning by, adverse effect of and underdosing of phenothiazine antipsychotics and neuroleptics
T43.3X for Poisoning by, adverse effect of and underdosing of phenothiazine antipsychotics and neuroleptics
T43.4 for Poisoning by, adverse effect of and underdosing of butyrophenone and thiothixene neuroleptics
T43.4X for Poisoning by, adverse effect of and underdosing of butyrophenone and thiothixene neuroleptics
T43.5 for Poisoning by, adverse effect of and underdosing of other and unspecified antipsychotics and neuroleptics
T43.50 for Poisoning by, adverse effect of and underdosing of unspecified antipsychotics and neuroleptics
T43.59 for Poisoning by, adverse effect of and underdosing of other antipsychotics and neuroleptics
T43.6 for Poisoning by, adverse effect of and underdosing of psychostimulants
T43.60 for Poisoning by, adverse effect of and underdosing of unspecified psychostimulant
T43.61 for Poisoning by, adverse effect of and underdosing of caffeine
T43.62 for Poisoning by, adverse effect of and underdosing of amphetamines
T43.63 for Poisoning by, adverse effect of and underdosing of methylphenidate
T43.64 for Poisoning by ecstasy
T43.65 for Poisoning by, adverse effect of and underdosing of methamphetamines
T43.69 for Poisoning by, adverse effect of and underdosing of other psychostimulants
T43.8 for Poisoning by, adverse effect of and underdosing of other psychotropic drugs
T43.8X for Poisoning by, adverse effect of and underdosing of other psychotropic drugs
T43.9 for Poisoning by, adverse effect of and underdosing of unspecified psychotropic drug
T43.91 for Poisoning by unspecified psychotropic drug, accidental (unintentional)
T43.92 for Poisoning by unspecified psychotropic drug, intentional self-harm
T43.93 for Poisoning by unspecified psychotropic drug, assault
T43.94 for Poisoning by unspecified psychotropic drug, undetermined
T43.95 for Adverse effect of unspecified psychotropic drug
T43.96 for Underdosing of unspecified psychotropic drug
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.
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Type 1 Excludes
- appetite depressants T50.5
- barbiturates T42.3
- benzodiazepines T42.4
- methaqualone T42.6
- psychodysleptics hallucinogens T40.7 T40.9
Type 2 Excludes
- drug dependence and related mental and behavioral disorders due to psychoactive substance use F10 F19
7th Character Note
- The appropriate 7th character is to be added to each code from category T43
7th Character
- A - initial encounter
- D - subsequent encounter
- S - sequela
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
Certain ICD-10-CM categories have applicable 7th characters. The applicable 7th character is required for all codes within the category, or as the notes in the Tabular List instruct. The 7th character must always be the 7th character in the data field. If a code that requires a 7th character is not 6 characters, a placeholder X must be used to fill in the empty characters.
Indicates that a seventh character is to be assigned to codes in a subcategory.
Patient EducationClinical
Drug Reactions
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Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Code HistoryHistory
Questions About T43Overview
Is T43 a billable code?
No. This is a category header that groups the codes for poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified, and headers cannot be submitted on claims. Claims for poisoning by, adverse effect of and underdosing of psychotropic drugs, not elsewhere classified need a more specific code from this category, such as T43.011A, T43.011D, and T43.011S.
