You can retire between 62 and your full retirement age (FRA). Your FRA depends on the year you were born, and varies from 62 to 67. Doug Lemons, a Social Security expert, calculated that taking benefits early and investing them is not desirable unless one receives an ROI of 5% for benefits taken at 62 rather than the FRA, or an ROI of 3% for benefits taken at FRA rather than waiting until age 70.
