1. Whether a federal court seeking to identify the content of state law pursuant to Erie Railroad Co. v. Tompkins, 304 U.S. 64 (1938), may choose the option that expands liability under state law, absent clear, authoritative guidance from the state's courts.

2. Whether an administrator of a plan governed by the Employee Retirement Income Security Act of 1974 ("ERISA") waives application of the plan's antiassignment provision – with the consequence of enabling a medical provider to bring a lawsuit under ERISA – through the routine processing of a claim for benefits pursued by the provider for an ERISA participant.

Whether a federal court may choose the option that expands liability under state law, absent clear, authoritative guidance from the state's courts