About half of sponsors working with an RIA said participants are receiving education, compared to 40 percent of non-fiduciary advisors.

And half of sponsors said their RIA advisors are providing one-to-one participant advice, compared to only 29 percent of the competition.

RIAs were 64 percent more likely to offer investment advice to sponsors, 60 percent more likely to advice on plan design, and 34 percent more likely to support participant enrollment, according to the survey.

The survey's bottom-line clearly shows RIAs are performing better than the non-RIA competition, according to John Newman, managing director of retirement plan services at TD Ameritrade.

"RIAs excel with retirement plan sponsors because they serve them with the same investor-first approach they use with individual investors and families," said Newman in a statement.

Most of the sponsors surveyed—36 percent—are working with a brokerage firm that offers 401(k) services; 22 percent said they work with an advisory that only offers 401(k) services.

Sponsors reported high levels of satisfaction with RIAs. Nine in 10 said RIAs were knowledgeable when it came to investment products, and as many said they were supportive in helping sponsors meet their fiduciary requirements.

Despite that level of success, Newman suggested RIAs not get complacent, as 64 percent of sponsors said they are open to switching advisors in the next year.

The survey's data shows many plans could be improved from better advice. For instance, only 27 percent of sponsors said their plans are currently using target date funds, and only one quarter of sponsors have implemented an automatic enrollment feature.

Sponsors also said participants are hungry for more one-to-one advice from advisors.

Evaluating investment choices and improving participation rates are sponsors' top goals in the coming year, according to the survey.

"When plan sponsors consider the design of their retirement plans, it's clear that two things are paramount: creating the most effective investment menu and offering skilled investment advice to their participants," said Newman. "Frankly, RIAs are uniquely positioned to deliver both."

The survey also showed sponsors are lacking in knowledge when it comes to understanding their regulatory requirements.

"A lot is changing for employer-sponsored retirement plans, so it's not surprising that plan sponsors need more guidance and services for themselves and for their participants," said Newman.

"Now more than ever, RIAs are poised to shine for plan sponsors–they are hard-wired to deliver fiduciary support and investment advice in a way that other providers are not," he added.