Abstract: An adapter provides leveling and elevation adjustment between the grate and strainer head of a floor drain. The strainer head is cemented in hardened concrete and has an upper seat for removably accepting the grate. The strainer head also has a tubular body defining the tubular lumen that is the drain hole. The adapter for the grate has a base ring, a set ring and a plurality of jack screws. The base ring gets seated in the strainer head's seat. The set ring forms a replacement seat for the grate to seat. Jack screws threaded into inboard tabs of the base ring provide elevation adjustment to the overlying set ring. The jack screws are disposed relative the strainer head such that the tip end and lower exposed thread portions thereof occupy and travel in the tubular lumen of the strainer head.