Medicaid – A Federal program administered by the States to provide health care for certain poor and low-income individuals and families. Eligibility and other features vary from State to State. Medicare – A Federal insurance program that provides health care coverage to individuals aged 65 and older and certain disabled people, such as those with end-stage renal disease. Network — A group of physicians, hospitals, and other providers who participate in a particular managed care plan. Open enrollment – A set time of year when you can enroll in health insurance or change from one plan to another without benefit of a qualifying event (e.g., marriage, divorce, birth of a child/adoption, or death of a spouse). Open enrollment usually occurs late in the calendar year, although this may differ from one plan to another. Point-of-service plan – A form of managed care plan in which primary care physicians coordinate patient care but there is more flexibility in choosing doctors and hospitals than in an HMO. Preferred provider organization – A form of managed care in which you have more flexibility in choosing physicians and other providers than in an HMO. You can see both participating and nonparticipating providers, but your out-of-pocket expenses will be lower if you see only plan providers. Premium – The amount you pay to belong to a health plan. If you have employer-sponsored health insurance, your share of premiums usually are deducted from your pay. Primary care physician – Usually a family practice doctor, internist, obstetrician-gynecologist, or pediatrician. He or she is your first point of contact with the health care system, particularly if you are in a managed care plan. Reasonable and customary charge – The prevailing cost of a medical service in a given geographic area. 28