PROJECT ABSTRACT Over 24 million Americans are ≥65 years and have prediabetes. Prediabetes can be addressed using a public health approach: among the 20% of participants in the Diabetes Prevention Program (DPP) who were ages 60 and over, the diet and physical activity intervention conferred a 71% risk reduction of diabetes after an average follow-up of 3 years. The population of older adults is projected to more than double from 52.5 million in 2019 to ~100 million by 2060, and if projections hold, about half (48.3%) will have prediabetes. The proposed study will compare a DPP program Tailored for Older Adults and delivered via Telehealth (DPP-TOAT arm) to an in person DPP tailored for older adults (DPP arm) using a randomized, controlled trial design (n=230). Our preliminary data suggests DPP-TOAT is a feasible and acceptable way to deliver the DPP to older adults, and this will be the first study to compare the effectiveness and implementation of two strategies (telehealth versus in-person) to deliver a tailored DPP for the unique needs of the growing population of older adults. Eligible patients will be recruited through electronic health records (Epic and MyChart) and randomized to the 12-month DPP-TOAT or the in-person DPP program. The primary effectiveness outcome will be 6-month weight loss and implementation outcome will be attendance. We will use a pragmatic approach in order to inform future studies conducted in community-based and rural settings. Findings will inform best practices in the delivery of an evidence-based intervention that could reach the 24+ million adults aged 65 and over with prediabetes.