This research describes policy implementation components of a health system and explains how they affect outcomes. It argues that implemented policies affect various components of a health system in terms of service delivery, workforce, information, financing, medical products, technologies, leadership and governance. Using health system as framework of analysis, the paper explains that the outcome of health policy implementation determines the availability, quality and equitability of program service delivery. The paper goes on to argue that policy implementation barriers, such as demand-and supply-side barriers, market, insufficient resources, cultural barriers, imperfect communication, information, education, coordination, leadership and governance affect the poor and vulnerable groups in developed and developing countries from benefitting from public spending on public health policies and programs.