Medicare is a federal program that was created to help to take care of those citizens over the age of 65. It is a health care program that works in the same fashion as many of the single payer systems of other countries. This means that money is paid into the program via taxes to the government, and then the government distributes the health care via that tax money.
Medicare was created by the administration of President Lyndon Johnson in 1965 in response to the need to provide affordable health care to the aging population of the United States. In the signing ceremony of the law that brought Medicare into existence the President named former President Harry S. Truman as the first person to be on Medicare. This action of signing this law into place helped millions of senior citizens to finally have access to health care that they might not have had before.
The lasting effects of Medicare can certainly still be felt today. However it is debated as to if they are good or not. Most people (particularly those who are on Medicare) are heavy supporters of that system. However, some view this program as one that is a drain on the federal budget. They say that the money could be better used on other projects. The debate tends to be one between those who are arguing over the role of the government. This classic debate is one that will likely rage on for all time. This is just a part of the Medicare story. The larger point is that regardless, this program is here to stay. You should be interested in how it will effect you in the future and how it effects you now.