Only a small proportion of individuals with a substance use disorder (SUD) receive treatment. The shortage of SUD providers, particularly in rural areas, is an important driver of this treatment gap. Telemedicine could be a means of expanding access to SUD treatment. However, several key regulatory and reimbursement barriers to greater tele-SUD use exist, and both the Congress and the states are considering or have recently passed legislation to address these barriers. To inform these efforts, we describe how tele-SUD is currently being used. Using 2010–2017 claims data from a large commercial insurer, we identify characteristics of tele-SUD users and examine how tele-SUD is being used in conjunction with in-person SUD care. Despite a rapid increase in tele-SUD over the period, we find low use rates overall, particularly relative to the growth in tele-mental health. Tele-SUD is primarily being used as a complement to in-person care and is disproportionately used by those with relatively severe SUD. Given the severity of the opioid epidemic, the low-rates of tele-SUD use that we observe represent a missed opportunity. As availability of tele-SUD is expanded, it will be important to monitor closely which tele-SUD delivery models are being deployed and their impact on access and outcomes.