Abstract: Provided is a steering system for a vehicle that can accurately determine a degradation level of a steering actuator according to a traveling state of the vehicle. The steering system for the vehicle includes; a steering mechanism configured to steer wheels; a steering actuator configured to apply a driving force to the steering mechanism; and a controller configured to control the steering actuator. The steering mechanism includes a rack shaft that is movable in a vehicle width direction from a prescribed reference position. The controller is configured to calculate an evaluation value according to a use state of the steering actuator and to determine a degradation level of the steering actuator by comparing the evaluation value with at least one threshold that is set based on a moving amount of the rack shaft from the reference position and a vehicle speed.