Inclusion Criteria:  18 years of age or older Within 180 days of release or possible release (eligible for parole) to the community, but greater than 7 days to release to the community OR currently in probation. FOR THOSE IN PRISON: Relocating to a location within 30 km (approximately 60-minute commute) of the referred Narcology center. Each participant will be asked the address he/she is planning to reside under that will be immediately checked on the map to determine the travel time. A participant then will be asked if he/she would be willing to travel the distance to a particular OST site. If a person does not meet this inclusion criterion, he/she will be referred to a local harm reduction center. Meets ICD-10 screening criteria for pre-incarceration opioid dependence  Exclusion Criteria:  Pregnant or may become pregnant FOR THOSE IN PRISON: Will be released from prison in 7 days or less.