Nearly 70% of Millennials have no retirement plan, according to a new survey.

 The survey, by MainStreet.com and GfK Roper, found that more half of Millennials plan to use Social Security income to fund their retirement years, despite concerns about Social Security’s long-term viability.

The study also found that Americans are also taking Social Security payments earlier than they should. "As long as they are eligible, many Americans equate the date they retire with the date they file for Social Security," says Bill Meyer, co-founder of a private research and counseling firm called Social Security Solutions. "Instead, retirees should separate those decisions and look at Social Security as if it's another asset in their portfolio."

The survey found that two out of three Millennials expect to retire by the age of 65, although nearly 70 percent have not started planning or saving for retirement. Employee-sponsored retirement savings plans are instrumental in both millennials’ and Baby Boomers’ retirement planning strategies, with more than 60 percent of both groups contributing to them to use as a future source of income.

Seventy percent of Baby Boomers currently have life insurance, with the birth of a child typically fueling that purchase.