The District Court found that Cigna's initial descriptions of its new plan, such as those found in the summary plan document, were significantly incomplete and misled its employees, according to the Supreme Court decision. Among other shortcomings, the information failed to indicate that Cigna's initial deposit to fund its employees' new cash balance plans did not represent the full value of the benefit that employees had earned for service before 1998.

The case hinged on which description of the plan would prevail, according to Komornicka: the one found in Cigna's summary plan document (SPD), or the one in the plan documents themselves. "The lower courts said, 'we're going to say that the summary plan document holds and becomes the terms of the plan'," she notes. These courts, using ERISA § 502(a)(1)(b), reasoned that the SPD misled employees, who were harmed as a result.

The Supreme Court, however, "unanimously held that the plan terms can't be reshaped by 502(a)(1)(b)," says Vaughan. "The court took pains to describe the summary plan document as something separate from the plan itself." (Eight justices ruled on the case at the Supreme Court; Justice Sonia Sotomayor was not involved in the case.)

In other words, a legal claim brought under ERISA § 502(a)(1)(B) to collect benefits under a plan must be based on terms of the plan itself, says Michael Shpiece, a law professor at Wayne State University of Law and an employee benefits attorney with The Kitch Firm, Detroit. The claim can't be based on other materials that may describe or explain the plan.