ICD-10-CM 2027 diagnosis code
T40.991Poisoning by other psychodysleptics [hallucinogens], accidental (unintentional)
T40.991 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it and add the required 7th character.Short description: Poisoning by oth psychodyslept, accidental (unintentional)
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About T40.991
T40.991 is the ICD-10-CM diagnosis code for poisoning by other psychodysleptics [hallucinogens], accidental (unintentional). It belongs to category T40 (poisoning by, adverse effect of and underdosing of narcotics and psychodysleptics [hallucinogens]), block T36-T50 (poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances) and chapter 19 (injury, poisoning and certain other consequences of external causes). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.
Within T40.99, choose T40.991 (Poisoning by other psychodysleptics [hallucinogens], accidental (unintentional)) only when documentation doesn't support a more specific option: poisoning by other psychodysleptics [hallucinogens], intentional self-harm (T40.992), poisoning by other psychodysleptics [hallucinogens], assault (T40.993), poisoning by other psychodysleptics [hallucinogens], undetermined (T40.994), adverse effect of other psychodysleptics [hallucinogens] (T40.995) and underdosing of other psychodysleptics [hallucinogens] (T40.996).
Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
7th character
The appropriate 7th character is to be added to each code from category T40
Coding notes
- Poisoning by other psychodysleptics [hallucinogens] NOS
Notes that apply from higher levels
Instructions written at a parent level also apply to T40.991.
Broader instructions also apply from T36-T50 Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances and Chapter 19: Injury, poisoning and certain other consequences of external causes.
Table of Drugs & Neoplasms entries
- Bufotenine — Poisoning Accidental (unintentional)
- Diethyltryptamine (DET) — Poisoning Accidental (unintentional)
- Dimethyl › tryptamine — Poisoning Accidental (unintentional)
- Hallucinogen NOS › specified NEC — Poisoning Accidental (unintentional)
- Hawaiian Woodrose seeds — Poisoning Accidental (unintentional)
- Heavenly Blue (morning glory) — Poisoning Accidental (unintentional)
- Magic mushroom — Poisoning Accidental (unintentional)
- Mescal buttons — Poisoning Accidental (unintentional)
- Mescaline — Poisoning Accidental (unintentional)
- Morning glory seeds — Poisoning Accidental (unintentional)
- PCP › meaning phencyclidine — Poisoning Accidental (unintentional)
- Pearly Gates (morning glory seeds) — Poisoning Accidental (unintentional)
- Peyote — Poisoning Accidental (unintentional)
- Phencyclidine — Poisoning Accidental (unintentional)
- Psilocin — Poisoning Accidental (unintentional)
- Psilocybin — Poisoning Accidental (unintentional)
- Psilocybine — Poisoning Accidental (unintentional)
- Psychodysleptic drug NOS › specified NEC — Poisoning Accidental (unintentional)
- Yohimbic acid — Poisoning Accidental (unintentional)
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about T40.991
Is T40.991 billable?
- No. T40.991 is a header code. Report one of its more specific subcodes instead.