Abutment behavior signifi cantly influences the seismic response of certain bridge structures.Specifi cally in the case of short bridges with relatively stiff superstructures typical of highway overpasses,embankment mobilization and inelastic behavior of the soil material under high shear deformation levels dominate the response of the bridge and its column bents.This paper investigates the sensitivity of bridge seismic response with respect to three different abutment modeling approaches.The abutment modeling approaches are based on three increasing levels of complexity that attempt to capture the critical components and modes of abutment response without the need to generate continuum models of the embankment,approach,and abutment foundations.Six existing reinforced concrete bridge structures,typical of Ordinary Bridges in California,are selected for the analysis.Nonlinear models of the bridges are developed in OpenSees.Three abutment model types of increasing complexity are developed for each bridge,denoted as roller,simplifi ed,and spring abutments.The roller model contains only single-point constraints.The spring model contains discrete representations of backfi ll,bearing pad,shear key,and back wall behavior.The simplifi ed model is a compromise between the effi cient roller model and the comprehensive spring model.Modal,pushover,and nonlinear dynamic time history analyses are conducted for the six bridges using the three abutment models for each bridge.Comparisons of the analysis results show major differences in mode shapes and periods,ultimate base shear strength,as well as peak displacements of the column top obtained due to dynamic excitation.The adequacy of the three abutment models used in the study to realistically represent all major resistance mechanisms and components of the abutments,including an accurate estimation of their mass,stiffness,and nonlinear hysteretic behavior,is evaluated.Recommendations for abutment modeling are made. Abutment behavior signifi cantly influences the seismic response of certain bridge structures. Specifi cally in the case of short bridges with relatively stiff superstructures typical of highway overpasses, embankment mobilization and inelastic behavior of the soil material under high shear deformation levels dominate the response of the bridge and its column bent. This paper investigates the sensitivity of bridge seismic response with respect to three different abutment modeling approaches. abutment modeling approaches based on three increasing levels of complexity that attempt to capture the critical components and modes of abutment response without the need to generate continuum models of the embankment, approach, and abutment foundations. Sixy existing reinforced concrete bridge structures, typical of Ordinary Bridges in California, are selected for the analysis. Nonlinear models of the bridges are developed in Open Sessions. Three types of increasing abutment models of increasing complexity are develope d for each bridge, denoted as roller, simplifi ed, and spring abutments. The roller model contains only single-point constraints. The spring model contains discrete representations of backfi ll, bearing pad, shear key, and back wall behavior. model is a compromise between the effi cient roller model and the comprehensive spring model. Modal, pushover, and nonlinear dynamic time history analyzes are conducted for the six bridges using the three abutment models for each bridge. Comparisons of the analysis results show major differences in mode shapes and periods, ultimate base shear strength, as well as peak displacements of the column top obtained due to dynamic excitation. the adequacy of the three abutment models used in the study to realistically represent all major resistance mechanisms and components of the abutments, including an accurate estimation of their mass, stiffness, and nonlinear hysteretic behavior, is evaluated. Recommendations for abutment modeling are made.