The Labor Department's long-awaited regulations on 401(k) fee disclosure are here at last, and the pressure is on. As pricing of defined-contribution plans becomes more transparent, companies could start looking for a new plan or provider.

It may seem odd that companies don't grasp what something costs. But an October study by consultancy Callan Associates indicates that while companies appreciate the importance of 401(k) fees, "the number of sponsors that are unclear about the status of their plan's fees is remarkable," says Lori Lucas, Callan's defined-contribution practice leader.

According to the survey, about 13% of plan sponsors don't know what administrative fees apply to their company stock fund. And of those whose plans use revenue sharing, about a fifth do not know how many of their funds pay revenue sharing.