This paper presents a numerical study on the effect of backfill compaction on the static response of geosynthetic reinforced soil-integrated bridge system (GRS-IBS). The numerical simulations were performed in stages to simulate the construction process, and considered soil-geotextile, soil-block, geotextile-block, and abutment-bridge interactions. Backfill compaction was simulated using a temporarily-applied uniform vertical stress to each lift during construction. Simulation results of the GRS-IBS behavior corresponding to various levels of compaction effort are presented and discussed, including lateral facing displacements, settlements, and maximum tensile forces in the reinforcement layers. Results indicate that greater backfill compaction leads to smaller bridge seat settlement and backfill compression, but also results in larger lateral facing displacements.