Abstract: A height-adjustable work surface assembly including a movable work surface. A frame extends from beneath the work surface in order to provide support for the work surface. The frame has a support member directed downward from beneath the work surface. A leg is adjustably connected to the support member. A rack is connected to one of the support member and the leg. The rack includes a plurality of substantially horizontally extending teeth. An interlocking block is positioned adjacent the rack and within a cavity formed between the rack and the leg. The interlocking block is movable into and out of engagement with the rack. The cavity has a width greater than a width of the interlocking block and a width of one the teeth. A first fastening mechanism is connected to the interlocking block. The first fastening mechanism is horizontally movable such that the interlocking block is secured against the rack in a locked position and completely disengaged from the rack in an unlocked position.