The social movements of the last two decades have fostered a rights-based approach to health systems development within the global discourse on national and international health governance. In this piece, we discuss ongoing challenges in the cavernous “implementation gap ”— translating legislative victories for human rights into actual practice and delivery. Using accompaniment as an underlying principle, we focus primarily on constructing effective, equitable, and accountable public sector health systems. Public sector health care delivery is challenged by increasingly exclusive politics and inequitable economic policies that severely limit the participatory power of marginalized people. Finally, we discuss the role of implementation science in closing the delivery gap.