In many low- and middle-income countries, health coverage has improved dramatically in the last two decades, but health outcomes have not. As such, effective coverage -- a measure of service delivery that meets a minimum standard of quality -- remains unacceptably low. This Policy Research Report examines one specific policy approach to improving effective coverage: financial incentives in the form of performance-based financing (PBF) or financial incentives to health workers on the front lines. The report draws on a rich set of rigorous studies and new analysis. When compared to business-as-usual, in low-income settings with centralized health systems PBF can result in substantial gains in effective coverage. However, the relative benefits of PBF are less clear when it is compared to two alternative approaches, decentralized facility financing which provides operating budget to frontline health services with facility autonomy on allocation, and demand-side financial support for health services (i.e., conditional cash transfers and vouchers). While PBF often results in improvements on the margins, closing the substantial gaps in effective health coverage is not yet within reach for many countries. Nonetheless, there are important lessons learned and experiences from the roll-out of PBF over the last decade which can guide health policies into the future.