An adjustable camshaft for a valve train of an internal combustion engine may include an inner shaft that is rotatable in an outer shaft, a phase shifter by which the outer shaft and/or the inner shaft are/is adjustable in a phase position formed around an axis of rotation, and a bearing portion for bearing the camshaft, via which the phase shifter can be supplied with a pressurizing medium. The inner shaft may comprise an end on which a screw flange is arranged, and a rotor of the phase shifter may be connected to the screw flange. A free end of the inner shaft comprises a duct that coincides with the axis of rotation for at least partially supplying the phase shifter with a pressurizing medium. The duct may extend at least into the bearing portion.