Let's say you invest in a large-cap value fund with a 1.8 percent annual fee. But you see from the disclosure statement that a similar fund with comparable performance charges only 0.8 percent. In that case, why not switch to the cheaper fund?

"This is an opportunity to just take a step back and say: 'What funds am I invested in? Do they have high fees or low fees?'" says Scott Holsopple, CEO of Kansas-based Smart401k.

Of course, you need a diversified portfolio, so don't put all your money in one fund with only one type of asset just because it's the cheapest.

While fee information on each investment is helpful, Valletta says, employees should go further and calculate the total cost of their plan. Readers who hate math should skip the next three paragraphs

Start by looking up the annual cost of each fund you invest in. Multiply the annual cost by the account balance in the fund. Do that for each of your funds. Add up those dollar figures along with any other charges you pay that are listed on the statement.

Once you get the annual dollar figure you pay, divide it by your total 401(k) balance. That will give you the bottom-line cost of your 401(k).

For example, say you invest in two funds, each with a \$25,000 balance. One fund has an annual cost of 0.5 percent; the other 1.5 percent. That means you pay \$125 a year for the first fund and \$375 for the other. Divide your total fees — \$500 — by your \$50,000 balance and the total annual cost of your 401(k) is 1 percent.

The next question: Are you paying too much?

Be aware that small plans with few workers and modest assets will be more expensive than a giant plan that can negotiate lower fees and spread costs among thousands of employees.

The average total plan cost for small plans — with 100 participants who have an average balance of \$50,000 — is 1.3 percent, according to the "401k Averages Book." The typical cost for large plans with 1,000 workers is 1.08 percent.

If the total cost of your plan is higher than the average, you should ask your employer how your fees compare to other plans', Valletta says.

"Hopefully, they have gone through that exercise and know if the fees are competitive," he says.

Or, compare your plan to its peers at BrightScope.com, which rates 50,000 plans on fees, employer contributions and other factors. BrightScope calculates how many more years employees would have to work to catch up with workers in the top plan.

It's taken years to get these disclosures, so when you get the statement, review it. If it turns out you're paying high fees, you can take steps that might make a big difference for your retirement.

eileen.ambrose@baltsun.com