A spinal interbody device, system and method can include use of an interbody cage and plate. The interbody cage can include at least one of a key and a keyway configured to mate with at least one of a mating keyway and key located on the plate. The key and keyway can be configured such that the cage and plate are quickly and easily attached and detached from each other, and such that positional relationship between the cage and plate can be arrived at quickly, accurately, and with tactile and/or audile notice to the practitioner.