Abstract: A modular cover system for a vehicle cargo bed includes a cover support frame mountable to the front wall and sidewalls of the cargo bed, a plurality of modular cover panels, and a seal configured for installation over a perimeter margin of the cover panels and the front, rear and sidewalls of the vehicle bed. Each panel is bounded by a rail, configured to include a forwardly projecting tongue and a corresponding groove at the rear. The panel rails provide sufficient support to permit removal of selected adjacent panels to provide open spaces for tall cargo. Each panel includes a latch operable to selectively secure the panel to the side bed rails or release the panel from the side bed rails, thereby enabling a user to selectively release one or more panels from the cover system.