Half of millennials do not believe Social Security will still exist when they are ready to retire, a survey released Wednesday by the iOMe Challenge and conducted by the St. Norbert College Strategic Research Institute found. Over one-quarter of millennials believe Social Security will still exist, but they will receive smaller benefits.

The report found that the traditional three-legged stool so many of today's retirees depended on would be reduced to one primary leg, that of personal savings and investments.

"When the views of Millennials on the future of Social Security are juxtaposed with employers' shift from a defined-benefit retirement to a defined-contribution model, it is clear that for Millennials, financing their retirement is going to rest far more on their individual shoulders," David Wegge, chair of the iOMe Challenge and executive director of the St. Norbert College Strategic Research Institute, said in a statement.