542 Substance-Related and Addictive Disorders
uals being maintained on a partial agonist, an agonist/antagonist, or a full antagonist
such as oral naltrexone or depot naltrexone. 
In a controlled environment:  This additional specifier is used if the individual is in an
environment where access to opioids is restricted.
Coding based on current severity:  Note for ICD-10-CM codes: If an opioid intoxication,
opioid withdrawal, or another opioid-induced ment al disorder is also present, do not use
the codes below for opioid use disorder. Instead, the comorbid opioid use disorder is indi-
cated in the 4th character of the opioid-indu ced disorder code (see the coding note for opi-
oid intoxication, opioid withdrawal, or a spec ific opioid-induced mental disorder). For
example, if there is comorbid opioid-induc ed depressive disorder and opioid use disorder,
only the opioid-induced depressive disorder code is given, with the 4th character indicating
whether the comorbid opioid use disorder is mi ld, moderate, or severe: F11.14 for mild opi-
oid use disorder with opioid-induced depressive disorder or F11.24 for a moderate or se-
vere opioid use disorder with opi oid-induced depressive disorder.
Specify current severity:
305.50 (F11.10) Mild:  Presence of 2–3 symptoms.
304.00 (F11.20) Moderate: Presence of 4–5 symptoms.
304.00 (F11.20) Severe:  Presence of 6 or more symptoms.
Specifiers
The “on maintenance therapy” specifier applies as a further specifier of remission if the in-
dividual is both in remission and receiving maintenance therapy. “In a controlled environ-