While only 18 percent of employees participate in advisory services through their 401(k) plans, they report having a more positive outlook about their retirement plans as opposed to those who do not, according to the Mercer Workplace Survey.

"This is great news for plan sponsors who offer advisory services in their 401(k) plan as there is a clear correlation between positive retirement sentiment and engagement with these services," says Dave Tolve, administration product leader for Mercer. "Yet with relatively low usage among participants – especially when you start to look at the demographics – there is still work to be done."

Among respondents who participate in advisory services, they expect to have enough money to pay for health care at 49 percent, 40 percent plan to live as well or better during retirement, and 26 percent of respondents can help younger family members with tuition or housing expenses. Meanwhile, for respondents who do not participate in advisory services, 35 percent, 29 percent plan to live as well or better during retirement, and 15 percent can help younger family members with tuition or housing expenses.