An access door may include a core, first and second stiles defined along opposites sides of the core such that the core between the first and second stiles defines a recessed pocket with each of the first and second stiles defining a channel therein extending longitudinally along an inwardly-facing edge thereof, bottom and top elongated panels each defining tongue members at opposite sides thereof and configured to be received transversely in the recessed pocket with the tongue members received within the channels defined along the inwardly-facing edges of the first and second stiles, wherein, with the top and bottom elongated panels received in the recessed pocket, exterior faces of the first and second stiles, exterior faces of the top and bottom elongated panels, and an exposed surface of the recessed pocket between the top and bottom elongated panels define an exterior surface of one side of the door.