On a downward trajectory: Defined contribution plan fees

What accounts for the dip? The survey authors cite heightened scrutiny of plan fees by lawmakers and judges.

"These falling costs are in line with the trend of lower fees even as assets grow, underscoring the impact of increased legislation and fear of potential lawsuits," the report states. "This downward trend also has been fueled by the heightened scrutiny around these fees by plan sponsors, their advisors and record-keepers themselves."

Among the report's additional findings about the DC plans surveyed:

• 87 percent have some level of revenue-sharing.

• 58 percent of have plan expense reimbursement accounts (PERAs). These accounts let plan sponsors capture dollars in excess of pre-determined recordkeeping fees and use them for other plan expenses.

• 52 percent have $1 billion or more in plan assets.

• 50 percent have contracted recordkeeping fees in a bundled or fixed-basis point structure.

• 47 percent have fixed-dollar per head recordkeeping arrangements. Of this total, 43 percent of mid-size plans were contracted in the last three years.

Though nearly 9 in 10 plans continue to rely on revenue-sharing, the report notes that retirement investment accounts with fixed-dollar per head fee models have the most plans with no revenue-sharing; and that large plans are more likely than small plans to have no revenue-sharing.

"While there has been much discussion in the industry about the appropriateness of revenue-sharing arrangements, regulators generally have been supportive of the practice of revenue-sharing to help pay a plan's administrative expenses," the study adds.