Health maintenance organization
In the United States, a health maintenance organization (HMO) is a medical insurance group that provides health services for a fixed annual fee. It is an organization that provides or arranges managed care for health insurance, self-funded health care benefit plans, individuals, and other entities, acting as a liaison with health care providers (hospitals, doctors, etc.) on a prepaid basis.
Source: Wikipedia — Health maintenance organization (CC BY-SA 4.0)