; (ii) is at least 21 years of age; (iii) has not attained 65 years of age; and (iv) has been diagnosed with at least one opioid use disorder. (B) Institution for mental diseases The term institution for mental diseases has the meaning given such term in section 1905(i). (C) Opioid prescription pain reliever The term opioid prescription pain reliever includes hydrocodone products, oxycodone products, tramadol products, codeine products, morphine products, fentanyl products, buprenorphine products, oxymorphone products, meperidine products, hydromorphone products, methadone, and any other prescription pain reliever identified by the Assistant Secretary for Mental Health and Substance Use. (D) Opioid use disorder The term opioid use disorder means a disorder that meets the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (or a successor edition), for heroin use disorder or pain reliever use disorder (including with respect to opioid prescription pain relievers). .