Out-of-Network: This phrase usually refers to physicians, hospitals or other health care providers who are considered nonparticipants in an insurance plan. Depending on an individual's health insurance plan, expenses incurred by services provided by out-of-plan health professionals may not be covered, or covered only in part by an individual's insurance company.

Out-Of-Pocket Maximum: A predetermined limited amount of money that an individual must pay out of their own pocket, before an insurance company will pay 100 percent for an individual's health care expenses.

Outpatient: An individual (patient) who receives health care services (such as surgery) on an outpatient basis, meaning they do not stay overnight in a hospital or inpatient facility. Many insurance companies have identified a list of tests and procedures (including surgery) that will not be covered (paid for) unless they are performed on an outpatient basis. The term outpatient is also used synonymously with ambulatory to describe health care facilities where procedures are performed.