At the request of Congress, this report presents findings and recommendations related to governance of the U.S. government's monitoring, detection, and verification (MDV) enterprise and offers findings and recommendations related to technical MDV capabilities and research, development, test, and evaluation efforts, focused in particular on the nuclear fuel cycle, nuclear test explosions, and arms control. Table of Contents Front Matter Summary 1 Introduction 2 Governance of the MDV Enterprise 3 Technical MDV Capabilities and Research and Development 4 Conclusion Appendix A: Statement of Task Appendix B: List of Findings and Recommendations Appendix C: Summary of the Defense Science Board Task Force Report: Assessment of Nuclear Monitoring and Verification Technologies Appendix D: Summary of the 2018 Plan for Verification, Detection, and Monitoring of Nuclear Weapons and Fissile Material Appendix E: Table of Technology Readiness Levels Appendix F: NNSA DNN (NA-20) Organizational Chart Appendix G: MDV at the Department of Energy National Laboratories Appendix H: NNSA's Over the Horizon Initiative Appendix I: Example Charter for the National Security Council's External Advisory Board for Monitoring, Detection, and Verification Assessment Appendix J: Table of Relevant Technical and Program Reviews Appendix K: Summary of Currently Funded NNSA/DNN R&D University Consortia Appendix L: Table of MDV R&D Technical Capabilities Needed for the Nuclear Fuel Cycle, Nuclear Test Explosions, and Arms Control Appendix M: MDV R&D Priorities Listed in the NDRD Strategic Plan for FY20202024 Appendix N: Committee Biographies Appendix O: List of Committee Meetings and Briefings