T40.9Poisoning by, adverse effect of and underdosing of other and unspecified psychodysleptics [hallucinogens]

T40.9 is the ICD-10-CM diagnosis code for poisoning by, adverse effect of and underdosing of other and unspecified psychodysleptics [hallucinogens]. 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 2 subcodes must be used instead.

Within T40, choose T40.9 (by, adverse effect of and underdosing of other and unspecified psychodysleptics [hallucinogens]) only when documentation doesn't support a more specific option: by, adverse effect of and underdosing of opium (T40.0), by and adverse effect of heroin (T40.1), by, adverse effect of and underdosing of other opioids (T40.2), by, adverse effect of and underdosing of methadone (T40.3), by, adverse effect of and underdosing of other synthetic narcotics (T40.4), by, adverse effect of and underdosing of cocaine (T40.5), by, adverse effect of and underdosing of other and unspecified narcotics (T40.6), by, adverse effect of and underdosing of cannabis (derivatives) (T40.7) and 1 more.

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.