Abstract: An adjustable, fastenerless modular shutter includes a pair of side rails, at least one shutter panel and a pair of end rails. A center rail can be provided. The side rails and end rails are mutually connected to form a frame for holding one or more shutter panels and center rails. Each end rails and the center rail has a front wall and a pair of runner portions having locking portions. The locking portions are slidably receivable in the pair of side rails and include interferingly, frictionally engaging projections for engaging the side rails to resist separation of the end rails from the side rails during assembly of the shutter. The side rails include front inwardly directed lips which assist in retaining the shutter panelis), the center rail and the end rails, particularly the runner portions. The end rails and the center rail include front surfaces raised from their respective runner portions to be planar with front surfaces of the side rails when the shutter is assembled.