Sixty-six percent of Bloom Health's defined-contribution private exchange customers opted to increase their take-home pay last year by choosing "less rich" coverage than they had prior to using the Bloom platform—when they had fewer choices and little, if any, decision support.

Eleven percent of Bloom's customers chose to invest in richer coverage than they previously had, and 23 percent chose benefit levels similar to what they already had.

"Our experience and data shows that when you give people the ability to make personal decisions about the benefits that best fit their needs, there is a real opportunity for savings and increased take-home pay for employees," Bloom Health CEO Simeon Schindelman said in a statement.

Premium contributions for employees using the Bloom system are 20 percent below the national average, the company said.

"When we give employees choice and control over their wage vs. coverage tradeoff, our data clearly shows that they overwhelmingly choose to increase take-home pay," Schidelman said.

Bloom, which has more than 150 companies on its platform, is one of several companies to launch private exchanges since the passage of the Patient Protection and Affordable Care Act.