Thirty years ago, half of all workers in the United States had a traditional pension plan, according to the U.S. Department of Labor. That meant that in retirement, they received a decent-sized check in the mail each month. By 2010, the percentage of employees covered by a pension plan had slipped to 7%. Today, the lion's share of companies (69%) sponsor 401(k) retirement plans. But not all employees participate, and some who do participate fail to tuck away enough of their salaries to ensure an adequate retirement.

Although 74.4 million workers have amassed $3.1 trillion in savings in their 401(k) plans, according to a 2012 Deloitte study, that's a drop in the bucket. In a separate Deloitte survey of a broad base of employers earlier this year, 15% said less than half their employees participated in the 401(k) plan. With regard to participants' savings rate, employees in the half of the plans that required automatic enrollment were saving a paltry 3%, according to the Defined Contribution Institutional Investment Association.