In this paper, the economical and structural efficiency of friction pendulum bearings (FPB) for retrofitting typical seismically vulnerable bridges in the State of Illinois is studied. For this purpose, a bridge was carefully selected by the Illinois Department of Transportation (IDOT) to represent typical seismically vulnerable bridges commonly used in the State of Illinois. A comprehensive structural model of the bridge was first constructed for seismic analysis. An iterative multi-mode response spectrum (MMRS) analysis of the bridge was then conducted to account for the nonlinear behavior of the bridge components and soil-bridge interaction. The calculated seismic demands were compared with the estimated capacities of the bridge components to determine those that need to be retrofitted. It was found that the bearings, wingwalls and pier foundations of the considered typical bridge need to be retrofitted.