摘要：While Social Security provides a guaranteed lifetime benefit, it is insufficient for most people to maintain their pre-retirement standard of living. Thus, except for people with low pre-retirement incomes, most people need to supplement their Social Security benefits with other sources of income. While low-income retirees tend to rely largely on Social Security, other retirees tend to have other sources of retirement income. However, as people grow older, especially for those living past their life expectancy, they risk having exhausted their sources of income other than Social Security.
