A power electronics module includes a frame, a jet impingement cooler assembly, and a power electronics assembly. The frame includes a first surface, a second surface, a power electronics cavity within the first surface of the frame, a fluid inlet reservoir, and a fluid outlet reservoir. The fluid inlet and outlet reservoirs extend between the first surface of the frame and the second surface of the frame. The fluid inlet reservoir and the fluid outlet reservoir are configured to be fluidly coupled to one or more additional modular power electronics devices. The jet impingement assembly is sealed within the frame and fluidly coupled to the fluid inlet reservoir and the fluid outlet reservoir. The power electronics assembly includes at least one power electronics component, is positioned within the power electronics cavity, and is thermally coupled to the jet impingement cooler assembly. Power electronic module assemblies are also disclosed.