Decoding 401(k) fees: What you need to know to make great decisions

(CBS News) Yale professor Ian Ayres is taking aim at corporate America -- he looked at the fees workers are paying on their retirement plans, and then wrote a letter to 6,000 companies that he believes are charging the most. Ayres is threatening to publish their names.

But how do you know if you're paying too much for 401(k) fees without Ayres' list?

"CBS This Morning" turned to CBS News financial analyst Jill Schlesinger, who explained employees pay two levels of fees on 401(k) plans. The first level are plan fees, which include administrative and trustee fees. The second are additional fees --the ones Ayres is concerned about -- for the underlying investments inside the plans. Those fees, Schlesinger said, can range from one percent -- on the low end -- to sometimes as high as three percent.

But Schlesinger noted employees don't have to be in the dark -- they can know what they're paying due to new rules enacted last year that mandate your plan send you a detailed analysis of the 401(k) fees you're paying.

If you don't like what you find and want to improve your plan, Schlesinger advised, "You can try to get a group together and say, 'Hey, boss, can you give us a better plan? Or, choose other options within your plan that are cheaper, maybe an index fund or maybe something less expensive than the other kind."

Schlesinger noted it's employers that are making decisions about your plan. "Some of the companies don't spend a lot of money doing it," she said. "And often this has a big tilt toward smaller and medium companies that don't have the purchasing power to get a really good plan, so if you look at large plans like a CBS plan, the fees are really pretty cheap -- they're less than 1 percent. Then you look at these poor people who work at a 50- or 100-person company and they've got some lousy insurance product and it's costing them two-and-a-half percent a year because their boss is golfing buddies with the insurance sales guy."

She continued, "Sometimes they pile it in with their payroll plans. But the long and short of it is, now that they have to disclose the fees, employees have more power, and you should be going to your HR department and saying, 'Hey, don't we all want a better plan, this could really end up costing you so much money in the long run, and you know, frankly, the boss' too."

For more of Schlesinger's analysis, watch her full interview above.