Substance use treatment; Outpatient; Outpatient methadone/buprenorphine or naltrexone treatment; Regular outpatient treatment; Methadone used in Treatment; Buprenorphine used in Treatment; Does not treat alcohol use disorder; Buprenorphine maintenance; Federally-certified Opioid Treatment Program; Methadone maintenance; Methadone; Buprenorphine with naloxone; Buprenorphine without naloxone; Anger management; Brief intervention; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; Private for-profit organization; State Substance use treatment agency; State mental health department; Commission on Accreditation of Rehabilitation Facilities (CARF); Federal, or any government funding for substance use treatment programs; Medicare; Medicaid; Cash or self-payment; Pregnant/postpartum women; Clients with HIV or AIDS; Comprehensive substance use assessment; Outreach to persons in the community; Complete medical history/physical exam; Screening for substance use; Breathalyzer or blood alcohol testing; Drug and alcohol oral fluid testing; Drug or alcohol urine screening; HIV testing; STD testing; TB screening; Aftercare/continuing care; Discharge Planning; Naloxone and overdose education; Outcome follow-up after discharge; Housing services; Assistance with obtaining social services; Mentoring/peer support; HIV or AIDS education, counseling, or support; Hepatitis education, counseling, or support; Health education services other than HIV/AIDS or hepatitis; Substance use disorder education; Individual counseling; Group counseling; Family counseling; Smoking permitted in designated area; Adults; Young adults; Female; Male; Opioid use disorder clients only; Case management service; Mental health services; Social skills development; Transportation assistance