A composite panel system for attaching to a wall system includes a layer of continuous insulation covering the wall system and a plurality of vertical girts affixed the wall system such that the continuous insulation lays between the wall system and the vertical girts. Composite panels are mounted to a perimeter frame of extrusions, generally two horizontal and two vertical. The panel frame horizontal extrusions are mounted to the vertical girts by fasteners. In some embodiments, gypsum and a membrane are used in lieu of continuous insulation.