A controversial appeals court decision from August could push US employers to rethink their oversight of service providers delivering workplace benefits.

In Bugielski v AT&T, former employees Robert Bugielski and Chad Simecek led a class action alleging that the fiduciaries of the company’s 401(k) pension fund failed to thoroughly investigate “excessive” fees charged by the plan’s record-keeper. AT&T was later dropped as a defendant from the case.