5. Remember that fee comparisons aren't created equal.
The two most debated aspects of 401(k) plans are breadth of investment offerings and the fees associated with those offerings. Blanchett said complaints about investment options are on the wane, rightly so. "Most plans are OK there, and to be honest, the things that are missing are the ones people won't realize they are missing."
Fees, though, continue to be a bone of contention in the retirement plan market. There's just one very important thing to remember if an employee does want to discuss fees with their employer: You have to compare the fees on your plan to fees on similarly-sized plans. Sure, in a perfect world it wouldn't matter if you worked for Exxon Mobil or a local grocery store in terms of the competitiveness of plan fees, but the truth is, it makes all the difference in the world: The larger the plan is, the better it can negotiate with vendors for lower-fee investment offerings.
"When someone tells me they think their 401(k) fees are too high, I always ask, 'Compared to what?'" Adams said. When an online financial tool is suggesting that you're paying too high a fee, know what the basis of comparison is. It's not just size. Are there fees or services you have access to in your plan but aren't using?
Remember the wider demographic of the plan: Sometimes you might pay for a certain service that is part of the package and one that is of value to the plan as a whole, Adams said.
"There are legitimate complaints," Johnson said, but he again stressed being an educated complainer. "When I meet with individual clients, my advice to them if they want to have this conversation with the boss is to go in and offer solutions. If you go on BrightScope and it says your plan fees are high compared to the average, then go in and say, 'Hey, here is what Fidelity will come in and offer, and here is what Vanguard will do."
6. Understanding the chess match of the company match.
A company match pegged to an employee contribution is one of the best benefits of a 401(k)—Blanchett said research shows it improves participant behavior—but it is at the discretion of the employer. For many small-business employers, the company match was a feature that became a casualty of the recession. Now that business in America is booming again, have all those rescinded matches come back? The experts say no, and that's one delicate conversation that employees of small firms have every right to seek out with their bosses.
"We're quite a few years removed from the crisis, and if a plan has not added [the match] back, if I'm that person, I would ask: 'It was in here before. Why isn't it back?'" Blanchett said.
"The biggest complaint we get is that there is no match or the company cut down on match. That's No. 1," Johnson said. Even big public companies cut back on the match, and at companies of 50 or less employees, the issue is widespread, he said.
"Five years ago, people didn't know if they would survive and now are a little out of survival mode and asking where does the business invest," Johnson said. "They could invest more in the 401(k), and it's an easy thing to do."
Of course, easier said than done.
"The reality is it's a form of confrontation," Blanchett said. But it's also a negotiation: Even if the employer does not agree to restart the company match, it's possible they could offer an employee a pay raise to make up for it.
Johnson said another potential negotiation is with employers who feel bad about cutting a match, and even if they won't bring it back yet, they might be more willing to listen to employee suggestions for lower-fee 401(k) plans to switch over to. "That's where you have to have a mature conversation and put yourself in the shoes of the other person, sniff out whether the boss is being greedy or really having a hard time keeping the doors open," Johnson said.
He said it is also important to remember that in many cases, employers may have simply lost sight of the match relative to all of the other issues they deal with as business recovers. Sometimes it's not that they are thinking of the cost, it's just that they don't have the time to think about it at all.
"I have the conversation with a lot of bosses who own a dental or medical practice or small manufacturing or sales company—the core of our economy, with 15 to 50 employees—and they are just busy folks and often haven't thought about any of these issues long enough to implement solutions," Johnson said.
—By Eric Rosenbaum, CNBC.com