Objective - Tanzania, Mexico, and the United States are at vastly different points on the economic development scale. Yet, their health systems can be classified as "developing": they do not live up to their potential, considering the resources available to them. The three, representing many others, share a common structural deficiency: a segregated health care system that cannot achieve its basic goals, the optimal health of its people, and their possible satisfaction with the system. Segregation follows and signifies first and foremost the lack of financial integration in the system that prevents it from serving its goals through the objectives of equity, cost containment and sustainability, efficient production of care and health, and choice. Method - The chapter contrasts the nature of the developing health care system with the common goals, objectives, and principles of the Emerging Paradigm (EP) in developed, integrated - yet decentralized -systems. In this context, the developing health care system is defined by its structural deficiencies, and reform proposals are outlined. Findings - In spite of the vast differences amongst the three countries, their health care systems share strikingly similar features. At least 50% of their total funding sources are private. The systems comprise exclusive vertically integrated, yet segregated, "silos" that handle all systemic functions. These reflect and promote wide variations in health insurance coverage and levels of benefits - substantial portions of their populations are without adequate coverage altogether; a considerable lack of income protection from medical spending; an inability to formalize and follow a coherent health policy; a lack of financial discipline that threatens sustainability and overall efficiency; inefficient production of care and health; and an dissatisfied population. These features are often promoted by the state, using tax money, and donors. Policy implications - The situation can be rectified by (a) "centralizing"at any level of development and resource availability - health system finance around a set package of core medical benefits that is made available to the entire population and (b) "decentralizing" consumption and provision of care. The first serves equity and cost containment and sustainability. The second supports efficiency and client satisfaction. Originality/value of chapter - The chapter views commonly discussed problems of the health care system - a lack of insurance coverage and income protection - as symptoms of a large problem: health system segregation.