Given today's unsure retirement environment, many employees are searching for options besides their 401(k) plans, especially considering how long people typically live after retirement, says Clark Frese, principal at Asset Strategy Retirement Plan Consultants and an adviser at the Institutional Retirement Income Council. Unlike previous generations, employees on the cusp of retirement live much longer, and more funding is necessary to counter these longer lives.

"Many people are living 30 years or so into retirement, where our grandparents only lived about five or six years into retirement," Frese says. "The generations that are planning for retirement now have a whole different set of responsibilities for themselves because you can imagine the difference between planning for 30 years or five or six years. Thirty years seems like a lifetime."

With guaranteed-income products, such as annuities, there is an added sense of security, which may be appealing to pre-retirees, says Chris Carosa, chief contributing editor of Fiduciary News. However, the guaranteed income isn't the only reason there has been an influx toward annuities. Commissions are high on these types of products; thus, insurance agents have an extra incentive to sell more annuities.