An implantable medical pump system can include a blood pump comprising a pump housing defining a passage therethrough and a rotor within the passage. The blood pump further includes one or more elements at least partially contained within the housing adapted to actuate the rotor to drive fluid though the passage. The pump housing includes at least one coupling feature. The system further includes an inflow cannula defining a lumen therethrough. The inflow cannula is adapted to be mechanically coupled to the at least one coupling feature.