The invention relates to an adjustable camshaft for the valve gear of an internal combustion engine, comprising an outer shaft, on which at least one first cam is arranged and connected to the outer shaft in a rotationally fixed manner, and an inner shaft extending through the outer shaft, to which inner shaft at least one second cam is connected in a rotationally fixed manner, wherein the second cam connected to the inner shaft in a rotationally fixed manner has a cam hole and is rotatably supported on a seating point on the outer shaft. According to the invention, at least one oil groove is introduced at the seating point in the outer shaft and/or in the inner wall of the cam hole, into which oil groove oil is guided from a gap between the outer shaft and the inner shaft through at least one passage extending through the outer shaft.