Social Security retirement benefits were first introduced in 1935 as a financial safety net for a large and rapidly growing older American population. The program was intended to be economically selfsustaining, but population aging and rising life expectancies threaten the program's solvency. The 1983 Social Security Amendments mandated that the full retirement age increase to 67 by the year 2027. In this essay, we present evidence demonstrating that the rate of improvement in life extension at older ages accelerated after 1983. If the 1935 ratio of working years to retired years is maintained, early and full retirement ages of 66.5 and 69.4, respectively, were justified in 2009. Additional delays in the age of eligibility beyond those currently in effect would place significant financial burdens on individuals with lower life expectancies, the poor and near-poor, and the very old, and – absent additional reform – would exacerbate existing unequal access to entitlements within the system.