Image source: Getty Images.Social Security is undeniably one of the most ubiquitous sources of income for retirees.According to the Social Security Administration's June 2015 Fact Sheet, nearly 9 out of 10 individuals aged 65 and older are receiving Social Security benefits, and among elderly beneficiaries, 53% of married couples and 74% of unmarried persons are receiving at least half of their income from Social Security.