If you've got a less-than-stellar 401(k) retirement savings plan — one with high fees and poor investment choices — financial advisors usually recommend a few workarounds such as diversification or a new fund. But some employees go one step further — taking their employers to court. They allege that their retirement preparedness was compromised because of the company's poor management of their 401(k) plan. Emboldened by a Supreme Court win and a string of settlements, employees have filed several new class-action lawsuits against employers. The cases usually center around excessive fees, poor plan designs and alleged conflicts of interest. "The focus has always been on practices of some plan sponsors that harm workers and retirees and limit their ability to build meaningful retirement wealth," said attorney Jerome Schlichter, whose St. Louis-based law firm represents many plaintiffs in these suits. Schlichter's firm has been responsible for winning more than $300 million in settlements or awards since the first suit of this type was filed in 2006. "When we started this, 401(k) plans were in a dark closet," he said. A recent example is a $62 million settlement against aerospace manufacturer Lockheed Martin, the largest of its kind. And last June, the Supreme Court heard a case against public utility Edison International, the first time the court has heard a 401(k) plan case. Employees argue that because their employers are considered fiduciaries when they offer a 401(k) plan, they've breached that duty by allowing high fees, bad fund choices and conflicts of interest. Even more cases may follow, reaching into other areas of 401(k) management. Read More From CNBC: Nearly Retired? Three Questions to Ask to Keep Your Money Safe "[Plaintiffs' lawyers] are looking for the next class-action bonanza, and I think it's most likely going to be in the ERISA area," said Marcia Wagner, managing director of the Wagner Law Group of Boston, referring to the Employee Retirement Income Security Act of 1974, which governs 401(k) plans and other retirement savings. The silver lining — at least for retirement savers — is that the lawsuits and the threat of litigation have helped drive down 401(k) fees, especially at large employers, by calling attention to the issue. "What you have is attorneys that are advising small companies telling them, 'You'd better get your act together because there is the threat of litigation,'" Schlichter said. "We've seen small- and medium-sized plans [lowering their fees]." According to BrightScope, a website that rates 401(k) plans, fees have been on a multiyear downward slide. The average plan participant paid a total cost of 0.89 percent of assets in 2013, down from 1.02 percent in 2009. Francis also worries that litigation has focused participants' attention too much on fees. The lowest cost fund may not always be the best option for investors, he said. Some funds — and fund managers — may be worth the cost. Yet employers may bypass them for fear of getting sued.