An operating system cartridge for an annular blowout preventer includes one or more annular walls that define an annular chamber. The operating system cartridge also includes a piston assembly that has an annular piston positioned within the annular chamber and a pusher plate configured to contact an annular packer assembly of the annular blowout preventer when the operating system cartridge is installed within a housing of the annular blowout preventer. The operating system cartridge further includes one or more fluid conduits extending through the one or more annular walls, wherein the one or more fluid conduits are configured to provide a test fluid to the annular chamber to facilitate testing of the operating system cartridge prior to installation within the housing of the annular blowout preventer.