Low-income groups have greater potential to gain from incorporating health promotion into daily living using bike-share to increase physical activity and expand transport options. The potential is unmet because of socioeconomics and access. Disproportionate uptake of bike-share by higher income individuals widens the gaps in health equity and transportation equity as bike-share use over-represents males with more resources, less need, and lower health risk. The Prescribe a Bike (RxBike) program, a key focus of this study, is a partnership between primary care providers (PCPs) at an urban safety net hospital and the city’s existing income-based, subsidized bike-share membership. Three studies using quantitative and qualitative methods were performed to: examine utilization of bike-share by Boston residents among subsidized and non-subsidized members; examine perceived attributes of the RxBike program by Boston Medical Center (BMC) PCPs; and evaluate BMC patient referrals. The overarching conceptual model uses elements of theories from health services and organizational behavior, in a public health framework. Analysis of Boston resident utilization at the trip-level (2012-2015) demonstrated overall ridership was increasingly by males and residents of more advantaged neighborhoods. Subsidized members had significantly higher likelihood of living in neighborhoods with socioeconomic and health disadvantage, and less gender disparity when compared to non-subsidized members. The impact was minimal because subsidized members made only 7.17% of trips. The survey of PCPs revealed mismatch between highly favorable opinion of RxBike appropriateness and lower intent to refer. Female gender and not being an urban biker predicted lower likelihood of intent to refer. Examination of open-ended survey comments mirrored quantitative data and expanded on the range of provider biking safety concerns in Boston. From 2013-2015, 27 BMC providers made only 72 referrals to RxBike. Patients referred had high cardiovascular health risk, resided in neighborhoods with extremely high levels of disadvantage, and in neighborhoods without meaningful access to bike-share kiosks. Overall, the subsidized membership extends reach of bike-share to residents of neighborhoods with more health and socioeconomic risk than the rest of the city; RxBike has strong potential to impact this vulnerable population. The most critical matters for program success are safety and neighborhood access.