A master brake cylinder system having a master brake cylinder housing having at least one first pressure chamber and a second pressure chamber, a rod piston at least partially displaceable into the first pressure chamber, a floating piston situated between the first pressure chamber and second pressure chamber, and a simulator device having a simulator piston, which is at least partially displaceable into the simulator chamber counter to a spring force of at least one simulator spring present in a simulator chamber, the simulator piston of the simulator device being situated as to the second pressure chamber so that the simulator piston is displaceable at least partially into the simulator chamber, using a pressure present in the second pressure chamber against the spring force of the at least one simulator spring. In addition, also described is a brake system for a vehicle having a master brake cylinder system.