Abstract: The present invention provides a modular submersible pump comprising a motor section, bearing section and a pump section. The motor section includes a motor frame and a motor shaft. The bearing section has a bearing frame removably connected to the motor frame of the motor section. A removable cartridge is disposed within the bearing frame and has a shaft extension connected to the motor shaft. The cartridge includes at least one bearing and at least one seal in communication with the shaft extension. The pump section has a pump case removably connected to the bearing frame and having an impeller disposed therein. The impeller is connected to the shaft extension of the removable cartridge.