The present invention relates to an adjustable camshaft (1) for the valve gear of an internal combustion engine, comprising an outer shaft (10), on which at least one first cam (11) is arranged and connected to the outer shaft in a rotationally fixed manner, and an inner shaft (12) extending through the outer shaft (10), to which inner shaft at least one second cam (13) is connected in a rotationally fixed manner, the second cam being rotatably supported on the outer shaft (10), wherein oil can be guided from a gap (14) between the outer shaft (10) and the inner shaft (12) to the region between the second cam (13) and the outer shaft (10) through an oil channel (15) in the outer shaft (10). According to the invention, the second cam (13) is at least partially sealed against the outer shaft (10) by means of at least one sealing element (16).