This application describes a 3-year, randomized controlled trial. Eligible, consenting adults (N=200) with existing sublingual buprenorphine (SLB) prescriptions who enter Middlesex County House of Corrections (MCHOC) as pre-trial detainees will be randomized at admission on a 1:1 basis to be inducted onto extended-release buprenorphine (XRB) at the time of admission (experimental condition) or remain in SLB (E-TAU; all participants will also receive naloxone). The two approaches will be compared with regard to (1) the percentage of participants released from jail with at least 7 days of buprenorphine in their system, (2) percentage of participants continuing MOUD treatment in the community, and (3) infractions related to buprenorphine diversion.