Systems and techniques used to control the use of health care services. Includes a review of medical necessity, incentives to use certain providers, and case management. The body of clinical, financial and organizational activities designed to ensure the provision of appropriate health care services in a cost-efficient manner. Managed care techniques are most often practiced by organizations and professionals which assume risk for a defined population (e.g., health maintenance organizations) but this is not always the case. Managed care is a broad term and encompasses many different types of organizations, payment mechanisms, review mechanisms and collaborations. Managed care is sometimes used as a general term for the activity of organizing doctors, hospitals, and other providers into groups in order to enhance the quality and cost-effectiveness of health care. Managed Care Organizations (MCO) include HMO, PPO, POS, EPO, PHO, IDS, AHP, IPA, etc. Usually when one speaks of a managed care organization, one is speaking of the entity which manages risk, contracts with providers, is paid by employers or patient groups, or handles claims processing. Managed care has effectively formed a “go-between”, brokerage or 3rd party arrangement by existing as the gatekeeper between payers and providers and patients. The term managed care is often misunderstood, as it refers to numerous aspects of healthcare management, payment and organization. It is best to ask the speaker to clarify what he or she means when using the term “managed care”. In the purest sense, all people working in healthcare and medical insurance can be thought of as “managing care.” Any system of health payment or delivery arrangements where the plan attempts to control or coordinate use of health services by its enrolled members in order to contain health expenditures, improve quality, or both. Arrangements often involve a defined delivery system of providers with some form of contractual arrangement with the plan. See Health Maintenance Organization, Independent Practice Association, Preferred Provider Organization.