The Science and Technology Directorate’s (S&T’s) Critical Infrastructure Resilience activities aim to improve understanding of the effects of EMP/GMD events on communications infrastructure and drive research activities to provide practical, data-driven, specific, and actionable information, concepts, techniques, technologies, and tools to critical infrastructure owners and operators to potentially mitigate the impact of and/or recover from EMP/GMD events. To address GPS vulnerabilities the Positioning, Navigation, and Timing (PNT) Program has a multi-pronged approach of conducting vulnerability and impact assessments, developing mitigations, exploring complementary timing technologies, and engaging with industry through outreach events and meetings. Through these sustained efforts, the goal of the program is to increase the resiliency of critical infrastructure to GPS vulnerabilities in the future.