Despite the magnitude of the impact the rule will have on advisor actions, many services offered by advisors remain "untouched" by the rule, the attorneys said.

For instance, an advisor that recommends a service provider to plan fiduciaries would "likely not be viewed" as a fiduciary for doing so, because the advisor would not be viewed as having full discretion, or final authority over the selection of a provider.

But advisors will be deemed to be acting as a fiduciary if they recommend investments for a fee or other compensation, write Saxon and Lee.

Here are several answers to specific questions advisors are airing relative to their responsibilities and liabilities under the rule, as offered in the fact sheet Groom's attorneys produced in accord with The Principal.

1. Do plan sponsors face a higher liability risk in selecting a plan provider/recordkeeper that is not the lowest-cost provider?

A: In short, no, say the attorneys. Sponsors have a fiduciary obligation to consider several factors when choosing a service provider—not just fees.

The lawyers quote a 1998 DOL letter: "The fiduciary need not select the lowest bidder, although the fiduciary must ensure that the compensation paid to a service provider is reasonable in light of the services provided to the plan."

Among the other factors plan fiduciaries should consider: needs of the plan; experience and past performance of similar plans under a prospective service provider's care; experience of the staff that will be handling plan assets; direct and indirect fees for services; existence of conflicts of interest; and the service provider's ability to provide information for plan reporting purposes.

Also, plan fiduciaries need to consider recordkeeping fees together with investment expenses when a portion of those expenses are used to pay for recordkeeping fees, write Saxon and Lee.

2. Do plan sponsors face a higher risk in selecting investments managed by the plan recordkeeper's affiliates?

A: In short, no, say the attorneys. The DOL's final is clear that proprietary products are allowable, so long as they are selected prudently.

The attorneys reference existing case law that says there is nothing intrinsically imprudent about sponsors selecting investments managed by an affiliate of a plan's recordkeeper.

The practice is not only common, but it often works to the benefit of sponsors and participants, note Saxon and Lee, quoting case law that says "many prudent investors limit themselves to investments offered by one company."

When a fiduciary sponsor or fiduciary advisor selects recordkeepers' proprietary investments, "it is unlikely" that would constitute a fiduciary breech under DOL's rule, without the presence of other facts "establishing imprudence or a conflict of interest," write the attorneys.

3. Can advisors (if they choose) avoid providing investment advice that would make them ERISA fiduciaries while recommending that the plan sponsor change the plan's recordkeeper?

A: "We believe so," say Saxon and Lee. "An advisor should be able to recommend a plan provider/recordkeeper without becoming a fiduciary, even if the recordkeeping services are bundled with a platform of investment options available to the plan."

To clarify, the attorneys note that the selection of a service provider is a fiduciary act for the plan's fiduciaries. But in merely recommending a service provider, an advisor is not acting in a fiduciary capacity, because they ultimately do not choose the service provider.

"Courts have concluded that a person is not a fiduciary as to the hiring of a plan service provider unless the person exercised the 'final authority' to hire the service provider," write the attorneys.

The DOL's rule is clear that a platform provider can offer a universe of investments without acting in a fiduciary capacity, so long as the provider discloses that it "is not undertaking to give advice in a fiduciary capacity," note the attorneys.

Despite the latitude in recommending a provider, Saxon and Lee recommend that advisors always pair a plan's needs with the capabilities and reasonableness of a recordkeeper's fees in any recommendation they give.

4. Does ERISA mandate any particular investment as necessarily prudent or imprudent?

A: No. This extends to actively managed investments, which are often more costly, say Saxon and Lee. ERISA's prudence requirements are emulated after trust law, which does not characterize any single investment as prudent or imprudent.

In the Best Interest Contract Exemption of its final rule, DOL explained that it does not specify "any particular investment product or category" as illegal or imprudent.

5. Has the DOL ever taken a position that actively managed investments are necessarily less appropriate for a 401(k) plan than passively managed investments?

A: No, say Saxon and Lee. Over the years, several DOL actions underscore that active investments can satisfy as ERISA's prudence requirements. Perhaps most notably, the DOL designated managed accounts, which deploy active management, as a qualified default investment alternative in the Pension Protection Act of 2006, note the attorneys.

6. Has a court ever ruled that actively managed investments are necessarily inappropriate for a 401(k) plan?

A: No, at least not to Saxon and Lee's knowledge. They say plaintiffs have failed to establish that the higher fees on actively managed investments made those options imprudent for 401(k) investors.

They cite a DOL advisory opinion, which says that fiduciaries "must consider, among other factors, the availability, riskiness and potential return of alternative investments" like actively managed funds.

7. Can plan fiduciaries reasonably conclude that a particular actively managed investment that they are selecting for the plan could be expected to outperform a comparable passively managed investment?

A: "We believe so," say the attorneys, who also note the extended academic debate over the value of actively managed investments.

"Some active managers have outperformed comparable passive managed investments," say Saxon and Lee. "Additionally, some investment professionals believe that actively managed investments have an advantage in down markets as they have greater latitude in investment selection."

8. Because actively managed investments could significantly underperform their benchmark indexes, plan fiduciaries would face a higher risk in offering actively managed investments than passively managed investments, right?

A: No, say Saxon and Lee.

"While it may be true that selecting and monitoring an actively managed investment would require more effort than selecting and monitoring a passively managed investment, plan fiduciaries who prudently select and monitor investments (whether active or passive) are not liable for the underperformance of the investments," they say.

Though plan fiduciaries who prudently select an investment would have a continuing duty to monitor the investment, the attorneys said "plan fiduciaries who satisfy their monitoring responsibility should not be liable if an actively managed investment fails to beat (on a net of fees basis) a comparable passively managed investment managed to the same benchmark."