You've heard the word "fiduciary" a lot recently, about a new Department of Labor (DOL) rule for financial advisors who advise individual investors about their retirement savings. But for business owners and executives who offer retirement plans for their employees, it's old DOL rules that are causing heartburn.

The reason: plaintiffs' lawyers have filed a blizzard of lawsuits alleging sponsors of retirement plans have breached their fiduciary duties. One law firm in Connecticut brought 19 actions under the Employee Retirement Income Security Act (ERISA) in a single year. St. Louis attorney Jerry Schlichter filed 18 lawsuits in the same period.

The list of defendants reads like a who's who of corporate America: Chevron, Cigna, Edward D. Jones, JP Morgan, Fidelity, Mass Mutual, Northrup Grumman, Oracle, United Health Group.

Schlichter's firm is reported to have negotiated settlements topping $300 million from firms like Boeing, General Dynamics, International Paper, including one for $62 million from Lockheed Martin.

So far, targets have mostly been big firms (and, interestingly, elite universities). But in financial markets, what starts at the top generally trickles down into the middle markets and to smaller firms, and ERISA litigation is likely to be no exception.

ERISA-based class action lawsuits come in several flavors, but they usually call out "excessive fees," alleging retirement plans cost participants more than they should have because the plans failed to offer the cheapest investment options, or have failed to negotiate appropriate fees with record keepers and other service providers.

Financial institutions that offer their own products as options in their retirement plans - particularly actively managed mutual funds with expense ratios higher than those on index funds or ETFs - are vulnerable to charges they violate ERISA's "reasonableness" standard.

Other lawsuits target too many fund offerings or poor investment performance, or offering a low-return money market fund when higher yielding cash investments - like stable value funds - might have been available.

At a time when virtually no retirement plan is safe from legal challenge, what can plan sponsors do to protect themselves?

First, hire specialists to help design the plan and select investment offerings.

When it comes to retirement plans, the primary thing owners and managers of mid-sized to small firms are thinking about is, "Are our employees using the benefit we're providing to them?" They don't have the understanding, expertise or even the time required to set up and act as proper fiduciaries of retirement plans.

Second, periodically and proactively review all vendor relationships in the retirement plan and what they are being paid. Every one to three years is probably often enough. The DOL has forms that can be used for this. And third-party benchmarking services are available which provide data about what "reasonable" compensation looks like for different kinds of vendors.

Third, buy fiduciary liability insurance. Your property and casualty insurer carries it and it's not that expensive.

Finally, write to your Congressman or Senator. The public policy irony is that ERISA-based class action lawsuits are having a chilling effect on defined contribution plans at a time when America's retirement savings crisis is becoming more and more acute every day.

The Pew Foundation reported in 2016 that only 22% of workers at small firms have access to a retirement savings plan at work.

US Senators Mark Warner (D-VA) and Susan Collins (R-ME) have introduced a bill that would ease the administrative and filing burdens of starting and maintaining a small employer retirement plan. But their bill doesn't address and won't solve the liability issue.

What would solve the liability issue is reconsidering why businesses that sponsor defined contribution plans should be fiduciaries at all. Fiduciary status made sense when businesses were making investment decisions on behalf of their employees in traditional defined benefit pension plans that determined how much participants would receive throughout their retirement. But in today's world of defined contribution 401(k) plans, where employees themselves are making choices about how to invest their retirement savings, ERISA fiduciary rules may be the wrong standard. And may have unintended negative consequences.