Introduction: Fontan patients have decreased exercise capacity. The COVID-19 pandemic exacerbated the variable adherence to hospital-based physical activity programs, which improve exercise capacity and attenuate the expected decline in aging Fontan patients. A positive pediatric exercise capacity trajectory has been reported to predict better adult Fontan outcomes. We designed and implemented a reimbursable 12-month, home-based, individualized physical activity program for Fontan patients utilizing a telemedicine model. Methods: Eligible participants must be able to complete a cardiopulmonary exercise test (CPET) and demonstrate ability to adhere to a 12-month exercise prescription. Assent and consent are obtained. CPET and informal surveys of physical activity self-efficacy are completed at enrollment and graduation. An individualized exercise prescription is provided, with focus on skeletal and respiratory muscle strength training and aerobic activities. Participants receive a Garmin© device to monitor adherence. A cardiologist, nurse coordinator, and exercise physiologists comprise the team and regularly communicate with participants, starting with weekly check-ins that gradually space out to monthly as participants gain confidence. Results: Since program initiation, 9 participants have completed the program and 3 remain active. For the 9 graduates, all scheduled in-person and telehealth visits were completed. At completion of the 12-month program compared to baseline, there was no difference in maximal or submaximal oxygen consumption (VO2), peak heart rate, or oxygen saturation, but there was a significant increase in systolic blood pressure (144 ± 16 vs 162 ± 15, p-value 0.004) and minute ventilation (68.8 ± 19.3 vs 76.8 ± 22.1, p-value 0.012) at peak exercise. Per subjective report, all graduates had increased confidence related to exercise. There were no adverse events in any participant. Conclusions: A novel, home-based, 12-month individualized physical activity program using telemedicine was successfully implemented, with no adverse events. A larger study is needed to better assess change in VO2 and other qualitative and quantitative parameters, although the lack of decline in exercise capacity is encouraging.