A step ladder device for improving the safe working elevation of a step ladder is provided. The step ladder device includes a working ladder portion that terminates in a rigid working tray providing a safety grab bar. The step ladder device is dimensioned and adapted to piggyback on to the step ladder so that the working ladder portion slidably moves in a coplanar orientation relative to the underlying step ladder, which enables the working tray to be locked in one of a plurality of selective working elevations relative to the underlying step ladder. As a result, the user can embrace the safety grab bar and balance themselves while standing on the upper rungs of the underlying step ladder or the lower rungs afforded by the working ladder portion.