The document defines various types of integrated delivery systems. An integrated delivery system is a network of organizations that provides coordinated care for a defined population and is responsible for their health status. Integrated systems vary in their breadth of services, depth of operating units, and degree of integration. Clinical integration coordinates care across functions to provide cost-effective, quality care. Structural integration brings organizations together under one structure while functional integration coordinates support functions. The Kaiser Permanente model exemplifies vertical integration through ownership of facilities and contracting with physician groups. Independent practice associations also integrate physicians virtually through contractual relationships without common ownership.