A leveling assembly for an interior wall system includes an elongate floor channel secured to the floor, a floor rail longitudinally disposed within the floor channel for supporting the wall panel, and levelers positioned along the floor channel. The levelers each include a base resting on the floor channel, a threaded rod projecting upwardly from the base, an outer threaded sleeve capable of telescoping movement over the threaded rod, and a threaded nut secured in an opening defined in a bottom surface of the floor rail. The threaded nut supports the floor rail. The levelers vertically space apart the floor rail from the floor channel.