Abstract: The staged plungers can be incorporated into virtually any type of fuel injector that utilizes plunger movement to raise fuel pressure in order to initiate and sustain an injection event. The staged plungers include an outer plunger with a rate shaping spill port. An inner plunger having a rate shaping bore is positioned to reciprocate within the inner bore of the outer plunger. A compression spring biases the inner plunger toward an advanced position relative to the outer plunger. Toward the beginning of the staged plungers' downward stroke at the beginning of an injection event, their relative movement produces rate shaping in the fuel leaving the injector as well as producing a split injection as the rate shaping spill bore of the inner plunger opens to the rate shaping spill port of the outer plunger.