Summary The private sector has a large and growing role in health systems in low-income and middle-income countries. The goal of universal health coverage provides a renewed focus on taking a system perspective in designing policies to manage the private sector. This perspective requires choosing policies that will contribute to the performance of the system as a whole, rather than of any sector individually. Here we draw and extrapolate main messages from the papers in this Series and additional sources to inform policy and research agendas in the context of global and country level efforts to secure universal health coverage in low-income and middle-income countries. Recognising that private providers are highly heterogeneous in terms of their size, objectives, and quality, we explore the types of policy that might respond appropriately to the challenges and opportunities created by four stylised private provider types: the low-quality, underqualified sector that serves poor people in many countries; not-for-profit providers that operate on a range of scales; formally registered small-to-medium private practices; and the corporate commercial hospital sector, which is growing rapidly and about which little is known.