The 2004 World Development Report emphasized that services are failing poor people – in terms of access, quantity, and quality. Public spending typically benefits the rich more than the poor, money often fails to reach frontline service providers, and service quality is consistently low for poor people. But services can work, as illustrated by project-level evaluation work by IEG over the past decade. This Strategic Engagement Area will assess the models most commonly used for service delivery in different sectors, and compare their effectiveness in reaching the poor, in terms of quantity, quality, access, behavior change and impact, and the sustainability of services over time.