Delaying Social Security until age 70 is beneficial since you will receive an 8% gain every year after achieving full retirement age (FRA), usually 66 for most people today. With average life expectancies rising, one of the main concerns for working Americans reaching retirement is: How can I ensure that I won't outlive my savings? Retirees should follow the modified 4% rule and reduce the amount for withdrawals from their retirement accounts every year after big losses or gains in their portfolios, inflation and other circumstances.