2026 ICD-10-CM Diagnosis Code T40Poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens]
T40 is a non-billable ICD-10-CM category code for poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens], so it cannot be submitted on claims. Use a more specific code from this category instead, such as T40.0X1A, T40.0X1D, T40.0X1S, and T40.0X2A.
Code Identity
Code Classification
Specific Coding for Narcotics and psychodyslepticsOverview
Non-specific codes like T40 require more characters. Use one of these billable codes instead:
T40.0 for Poisoning by, adverse effect of and underdosing of opium
T40.0X for Poisoning by, adverse effect of and underdosing of opium
T40.1 for Poisoning by and adverse effect of heroin
T40.1X for Poisoning by and adverse effect of heroin
T40.2 for Poisoning by, adverse effect of and underdosing of other opioids
T40.2X for Poisoning by, adverse effect of and underdosing of other opioids
T40.3 for Poisoning by, adverse effect of and underdosing of methadone
T40.3X for Poisoning by, adverse effect of and underdosing of methadone
T40.4 for Poisoning by, adverse effect of and underdosing of other synthetic narcotics
T40.41 for Poisoning by, adverse effect of and underdosing of fentanyl or fentanyl analogs
T40.42 for Poisoning by, adverse effect of and underdosing of tramadol
T40.49 for Poisoning by, adverse effect of and underdosing of other synthetic narcotics
T40.5 for Poisoning by, adverse effect of and underdosing of cocaine
T40.5X for Poisoning by, adverse effect of and underdosing of cocaine
T40.6 for Poisoning by, adverse effect of and underdosing of other and unspecified narcotics
T40.60 for Poisoning by, adverse effect of and underdosing of unspecified narcotics
T40.69 for Poisoning by, adverse effect of and underdosing of other narcotics
T40.7 for Poisoning by, adverse effect of and underdosing of cannabis (derivatives)
T40.71 for Poisoning by, adverse effect of and underdosing of cannabis (derivatives)
T40.72 for Poisoning by, adverse effect of and underdosing of synthetic cannabinoids
T40.8 for Poisoning by and adverse effect of lysergide [LSD]
T40.8X for Poisoning by and adverse effect of lysergide [LSD]
T40.9 for Poisoning by, adverse effect of and underdosing of other and unspecified psychodysleptics [hallucinogens]
T40.90 for Poisoning by, adverse effect of and underdosing of unspecified psychodysleptics [hallucinogens]
T40.99 for Poisoning by, adverse effect of and underdosing of other psychodysleptics [hallucinogens]
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 narcotics and psychodysleptics [hallucinogens] (T40). 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 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 T40
7th Character
- A - initial encounter
- D - subsequent encounter
- S - sequela
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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The full article covers:
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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 T40Overview
Is T40 a billable code?
No. This is a category header that groups the codes for poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens], and headers cannot be submitted on claims. Claims for poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens] need a more specific code from this category, such as T40.0X1A, T40.0X1D, and T40.0X1S.
