Conkright v. Frommert, No. 08-810, involved an ERISA action based on a plan administrator's interpretation of the benefits plan at issue to call for an approach known as the "phantom account" method. The Supreme Court reversed the Second Circuit's order affirming the district court's order declining to apply a deferential standard to the administrator's interpretation, on the ground that the district court should have applied a deferential standard of review to the administrator's interpretation of the plan on remand, despite the administrator's earlier mistaken interpretation.
As stated in the majority opinion, delivered by Chief Justice Roberts: "People make mistakes. Even administrators of ERISA plans. That should come as no surprise, given that the Employee Retirement Income Security Act of 1974 is "an enormously complex and detailed statute," Mertens v. Hewitt Associates, 508 U. S. 248, 262 (1993), and the plans that administrators must construe can be lengthy and complicated. (The one at issue here runs to 81 pages, with 139 sections.) We held in Firestone Tire & Rubber Co. v. Bruch, 489 U. S. 101 (1989), that an ERISA plan administrator with discretionary authority to interpret a plan is entitled to deference in exercising that discretion. The question here is whether a single honest mistake in plan interpretation justifies stripping the administrator of that deference for subsequent related interpretations of the plan. We hold that it does not."