Health services are organized in remarkably diverse ways and yet manage to produce comparable outcomes. Countries should build on the strengths of their own systems, rather than feel pressure to adopt health service organization models imported from elsewhere. Most countries have centralized and decentralized elements that coexist and generally are embedded in a wider governance and political economy context. Efforts to use decentralization to improve health outcomes succeed when they build organizational capacity to exercise newfound decision rights and ensure robust accountability systems. The private sector encompasses a diverse set of actors that play a critical role in delivering health services but that are often inappropriately neglected in public policy and planning efforts. There is no one perfect model of care, the best ones are adaptable and evolve to address shifting epidemiological patterns, emerging threats such as pandemics, and climate change. Addressing the organization and management of health services inevitably involves a focus on supply-side factors, but demand-side considerations play a critical role in improving health outcomes and cannot be ignored.