A deactivating cam system (1) for a valve train (1a) of an internal combustion engine is provided having a camshaft (2) on which at least one cam (3) is seated for rotation but fixed in axial direction while being able to be connected through a coupling device (4) rotationally fast to the camshaft (2). The coupling device (4) has a ball detent mechanism (5) which is arranged within the cam (3) and whose balls (6) are seated within radial pockets (7) of the cam (3).