Increased life expectancy and large numbers of baby boomers reaching retirement age will challenge the U.S. retirement income system. This article summarizes sources of retirement income and the importance of Social Security in providing income for poorer adults. It also discusses the financial shortfall in the Social Security system. Given the limited support for whole-scale reform, the author highlights options for adjusting Social Security and encouraging greater participation in employer-provided and individual retirement plans. (Oxford Review of Economic Policy 2006; 22(1); 95-112).