PROJECT SUMMARY In 2017-2018, we worked closely with the Rwanda Ministry of Health (MOH) to develop and pilot test a theory- based, multi-level intervention targeting postpartum family planning (PPFP) supply and demand in 5 government health facilities in Kigali, the capital. This innovative PPFP intervention is known as `C4' because it is informed by Clients, Clinic providers, Champions, and Community Health Workers. Long-acting reversible contraceptives (LARC), the intrauterine device (PPIUD) and implant, are fundamental to PPFP programs. LARCs are highly effective and are the only reversible methods that may be safely used in early postpartum period by breastfeeding women. During our pilot, LARC uptake among postpartum women increased significantly (172% for PP implant, 2,687% for PPIUD), PPFP feasibility and acceptability were high among providers and clients, and side-effects were rare. We now propose to use an implementation science framework to evaluate the effectiveness of different PPFP demand creation strategies and test the hypothesis that C4 is adaptable to large-scale implementation, cost-effective, and sustainable. In a Type 2 effectiveness- implementation hybrid study, we will evaluate facility organizational readiness prior to implementing C4 in a clinic randomized trial in 12 high-volume health facilities in Kigali, Rwanda (Aim 1). Adaptability and sustainability within government facilities is a critical aspect of our proposal, and the MOH and other local stakeholders will be engaged from the outset. We expect to deliver C4 PPFP counseling to over 21,000 women/couples during the project period. We will then evaluate C4 effectiveness and implementation processes using RE-AIM (Aim 2). We hypothesize that C4 will significantly increase the number of stakeholders engaged, PPFP providers and promoters, couples/clients receiving information about PPFP (reach), and LARC uptake (effectiveness) comparing intervention versus standard of care. We expect PPFP client satisfaction will be high and side-effects will be rare. The independent effectiveness of each demand creation strategy on LARC uptake will be estimated. We assess measures of C4 adoption, implementation, and maintenance at the patient-, provider- and stakeholder-level to assess C4 sustainability. Finally, we will evaluate C4 cost-effectiveness and develop a national costed implementation plan to guide Rwandan MOH decision-making for nationwide roll-out of PPFP services (Aim 3). We hypothesize that C4 will be cost-saving relative to standard of care. C4 represents an important contribution to the Rwanda Family Planning 2020 goals and the MOH are enthusiastic to see our successful pilot efforts expanded to a larger number of facilities for greater and sustained impact. Our PPFP implementation model is designed to be replicable and expandable to other countries in the region which similarly have high unmet need for PPFP.