A rain screen metal wall panel system is disclosed herein. Specifically, the system is directed to a metal wall panel assembly that includes a plurality of metal panels with a tab and slot design that accurately aligns the panels in three axes simultaneously. This increases the speed of installation while maintaining a properly aligned finished wall surface, join distances, and reduces cost by eliminating unnecessary clips and rails. The bottom panel(s) of the metal wall panel system of at least one embodiment includes a flat or generally planar bottom edge, with an attachment zee connection to the support structure.