Substance use treatment; Outpatient; Outpatient methadone/buprenorphine or naltrexone treatment; Regular outpatient treatment; No formal relationship with prescribing entity; Does not treat alcohol use disorder; Accepts clients using MAT but prescribed elsewhere; Brief intervention; Cognitive behavioral therapy; Contingency management/motivational incentives; Motivational interviewing; Relapse prevention; Substance use disorder counseling; Telemedicine/telehealth therapy; Trauma-related counseling; Private non-profit organization; State Substance use treatment agency; Council on Accreditation (COA); Federal, or any government funding for substance use treatment programs; Medicare; Medicaid; Federal military insurance (e.g., TRICARE); Private health insurance; Cash or self-payment; State-financed health insurance plan other than Medicaid; SAMHSA funding/block grants; Sliding fee scale (fee is based on income and other factors); Young adults; Adult women; Pregnant/postpartum women; Adult men; Seniors or older adults; Lesbian, gay, bisexual, transgender, or queer/questioning (LGBTQ); Veterans; Active duty military; Members of military families; Clients with co-occurring mental and substance use disorders; Clients with co-occurring pain 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; Interim services for clients; Outreach to persons in the community; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Aftercare/continuing care; Discharge Planning; Outcome follow-up after discharge; Treatment for gambling disorder; 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; Marital/couples counseling; Smoking permitted without restriction; Adults; Seniors; Young adults; Female; Male; Vaping permitted without restriction; Domestic violence services, including family or partner; Mental health services