PROJECT SUMMARY: A key challenge in combating the opioid epidemic has been connecting individuals with opioid use disorder (OUD) to evidence-based treatments. Telemedicine for opioid use disorder (“tele- OUD”) may be part of the solution. Use of tele-OUD grew rapidly during the pandemic and, in the first four years of this R01, we have made substantial progress in understanding its role in OUD treatment. To date, we have published 24 studies that examine a range of issues related to tele-OUD. These studies describe the growth of tele-OUD, examine the impact of the policy environment on tele-OUD use, assess the quality of tele- OUD, document disparities in tele-OUD use, and describe how clinicians are trying to address those disparities. However, key gaps in knowledge on the use of tele-OUD remain. We are proposing a renewal of our grant that uses data from Medicare, Medicaid, and commercial insurance, plus national pharmacy claims. Our Aims are to: 1) characterize clinicians who are using a fully-virtual model to treat OUD and compare clinical outcomes between virtual-only clinicians and other clinicians; 2) assess the role and quality impact of audio-only telemedicine for OUD treatment; and 3) identify trends in the number of pharmacies that dispense buprenorphine and assess the impact of pharmacy dispensing decisions on patient outcomes. The results from this project will inform provider use of tele-OUD as well as ongoing policy debates at the federal and state levels and among private health plans on payment and regulation of tele-OUD and its role in improving access and quality of care for individuals with OUD.