Pew found that 31 percent of private-sector employees it surveyed were not at all familiar with their retirement plan's fees.

Nearly a quarter of older adults in the U.S. said that in the past year they had not visited a doctor when sick, skipped a recommended test or treatment, not filled a prescription or skipped medication doses because of the cost.

Private benefits exchangescommercially marketed platforms on which employees can shop for a wide range of employer-sponsored health and voluntary benefitsare slowly growing and changing in response to market demands.