Medicare is a social insurance program that serves more than 44 million enrollees (as of 2008). The program costs about $432 billion, or 3.2% of GDP, in 2007.
The definition of an institution is an established custom or practice, or a group of people that was formed for a specific reason or a building that houses the group of people. 1  Marriage is an example of a cultural institution. 2  A town council is an example of an institution of government.
An institute is  an organisational body created for a certain purpose. Often they are research organisations (research institutions) created to do research on specific topics. An institute can also be a professional body, or one involved in adult education, see Mechanics' Institutes. In some countries institutes can be part of a university or other institutions of higher education, either as a group of departments or an autonomous educational institution without a traditional university status such as a university Institute.