Substance use treatment; Outpatient; Outpatient methadone/buprenorphine or naltrexone treatment; Methadone used in Treatment; Does not treat alcohol use disorder; Federally-certified Opioid Treatment Program; Methadone maintenance; Methadone; Anger management; Brief intervention; Cognitive behavioral therapy; Contingency management/motivational incentives; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Trauma-related counseling; Telemedicine/telehealth therapy; 12-step facilitation; Private for-profit organization; State Substance use treatment agency; State department of health; Commission on Accreditation of Rehabilitation Facilities (CARF); SAMHSA certification for opioid treatment program (OTP); Drug Enforcement Agency (DEA); Medicaid; Cash or self-payment; Adult women; Pregnant/postpartum women; Adult men; Seniors or older adults; Lesbian, gay, bisexual, transgender, or queer/questioning (LGBTQ); Veterans; Members of military families; Criminal justice (other than DUI/DWI)/Forensic clients; Clients with co-occurring mental and substance use disorders; Clients with HIV or AIDS; Clients who have experienced sexual abuse; Clients who have experienced intimate partner violence, domestic violence; Clients who have experienced trauma; Comprehensive substance use assessment; Outreach to persons in the community; Complete medical history/physical exam; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Breathalyzer or blood alcohol testing; Drug and alcohol oral fluid testing; Drug or alcohol urine screening; TB screening; Aftercare/continuing care; Discharge Planning; Naloxone and overdose education; Outcome follow-up after discharge; Housing services; Assistance with obtaining social services; 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; Smoking/vaping/tobacco cessation counseling; Individual counseling; Smoking not permitted; Adults; Seniors; Young adults; Female; Male; Opioid use disorder clients only; Vaping not permitted; Case management service; Social skills development; Suicide prevention services