An integrated delivery system (IDS) is a network of health care organizations under a parent holding company. Some IDS have an HMO component, while others are a network of physicians only, or of physicians and hospitals. Thus, the term is used broadly to define an organization that provides a continuum of health care services. There is some discussion over the efficiency and sustainability of IDS. Integrated delivery systems are one example of the emergence of managed care organizations in the United States.