Described are various embodiments of a luminaire and output element coupling mechanism therefor. In one embodiment, a recessable luminaire comprises two or more luminaire modules, each one of which comprising a recessable housing having opposed side walls. The luminaire further comprises an output element securable along and between these side walls to at least partially define an output of the luminaire, and opposed inwardly biased output coupling structures extending at least partially along respective side walls and adapted to receive and resiliently secure corresponding edges of the output element therein.