In addition, one out of five flunked, getting an F. (Millennials, incidentally, fared the worst, with 25 percent getting that F.)

But that’s not how employees see their understanding of benefits; 80 percent say they understand their benefits very well, and 74 percent feel very confident in their most recent annual enrollment period selections. (Some are more realistic, of course; 25 percent say choosing benefits is more of a “guessing game” than an educated decision.)

Employers aren’t quite so optimistic, with only 62 percent saying they believe employees have a strong understanding of how their benefits work. In addition, only 17 percent say their employees understand the monetary value of the benefits they get.

So what don’t employees understand?

Asked whether critical insurance illness payouts can reimburse caregivers for lost income, 57 percent incorrectly said that was true. Almost half (46 percent) didn’t know that the elimination period in disability insurance is the waiting period before collecting benefits.

Thirty-four percent incorrectly said that evidence of good health is required to apply for coverage by guaranteed issue insurance, while 30 percent did not know that hospital indemnity insurance pays for certain expenses not covered by their medical plan. And 22 percent mistakenly believed that LTD insurance replaces 100 percent of income in the event of serious illness or injury.

Employees aren’t all that confident about something else, though: that their employers are doing a good job educating them about their benefits. Just 47 percent said so, a drop from 66 percent who believed that just two years ago.

Employers, for their part, want to make workers more savvy on benefits; it may not be their first priority—the top answer among businesses surveyed in 2016 was “making plan design changes to reduce costs”—but “helping employees make better benefits decisions” was their second choice.

And since, according to the study, “many employers [seek] to invest in benefits that help attract and retain high-quality talent,” and 75 percent of employees who place a high value on their benefits want to stay with that employer for at least 5 years (compared with just 53 percent who don’t regard their benefits packages so highly), it’s a good thing helping employees is a high priority.