Progress has been made to advance multiple non-collisional techniques for runaway electron (RE) mitigation on the DIII-D tokamak. The first technique involves the implementation of a non-axisymmetric coil designed to passively drive large non-axisymmetric fields during the plasma disruption thereby destroying flux surfaces and deconfining RE seed populations. A new three-dimensional electromagnetic modeling tool ( ThinCurr ) has been developed using the existing PSI-Tet finite element code in support of conducting structure design work for both the SPARC and DIII-D tokamaks. This model includes accurate details of the vacuum vessel and other conducting structural elements with realistic material resistivities. This model was leveraged to support the design of a passive runaway electron mitigation coil (REMC), studying the effect of various design parameters, including coil resistivity, current quench duration, and plasma vertical position, on the effectiveness of the coil. A second technique for RE mitigation involves a novel combination of secondary gas injection and a vertical displacement event (VDE) which enables access to a large benign MHD kinking event which allows the RE wetted area to be greatly increased which lowers the chance of damage to plasma facing components. This ‘benign termination scheme’ was explored in recent DIII-D experiments to access the effect of secondary gas quantity and compression speed on access to the final loss event. An experiment was also completed to explore the potential wave-particle interaction between launched electron cyclotron waves and the RE population. These waves do not interact directly with relativistic electrons due to their low phase velocity nor can they be injected into plasma above the cutoff density. However, a unique opportunity exists to convert the “free space” O-mode into an internal plasma slow-X mode (a.k.a Z-mode). The phase velocity of the slow-X mode can exceed the speed of light, providing the possibility for direct RE-wave interaction. Access to this conversion window was observed in recent experiments completed on the DIII-D device.