Substance use treatment; Treatment for co-occurring substance use plus either serious mental health illness in adults/serious emotional disturbance in children; Outpatient; Intensive outpatient treatment; Outpatient methadone/buprenorphine or naltrexone treatment; Regular outpatient treatment; Methadone used in Treatment; Does not treat alcohol use disorder; Federally-certified Opioid Treatment Program; Methadone maintenance; Methadone maintenance for predetermined time; Methadone; Cognitive behavioral therapy; Motivational interviewing; Matrix Model; Relapse prevention; Substance use disorder counseling; Trauma-related counseling; Telemedicine/telehealth therapy; Private non-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); Federal, or any government funding for substance use treatment programs; Medicare; Medicaid; Private health insurance; Cash or self-payment; State-financed health insurance plan other than Medicaid; SAMHSA funding/block grants; Payment assistance (check with facility for details); Sliding fee scale (fee is based on income and other factors); Young adults; Adult women; Pregnant/postpartum women; Adult men; Comprehensive substance use assessment; Interim services for clients; Complete medical history/physical exam; Screening for tobacco use; Screening for substance use; Screening for mental disorders; Professional interventionist/educational consultant; Breathalyzer or blood alcohol testing; Drug and alcohol oral fluid testing; Drug or alcohol urine screening; STD testing; TB screening; Metabolic syndrome monitoring; Aftercare/continuing care; Discharge Planning; Naloxone and overdose education; 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; Group counseling; Family counseling; Smoking permitted in designated area; Adults; Young adults; Female; Male; Opioid use disorder clients only; Spanish; Vaping permitted in designated area; Case management service; Transportation assistance; Suicide prevention services