Some embodiments of an infusion pump system may include an occlusion sensor system that communicates with control circuitry to detect the presence of an occlusion. In some embodiments, the occlusion sensor system includes first components that are located within a disposable and non-reusable pump device, and second components that are located within a reusable controller device, the second components being in operable communication with the first components to determine whether a fluid is flowing from the pump device.