Dr. Radha Iyengar Plumb was confirmed as the Deputy Under Secretary of Defense for Acquisition and Sustainment (DUSD(A&S)) on April 18, 2023. In this role, she is responsible to the Under Secretary of Defense for all matters pertaining to acquisition; contract administration; logistics and materiel readiness; installations and environment; operational energy; chemical, biological, and nuclear defense; the acquisition workforce; and the defense industrial base.

Prior to this appointment, she served as Chief of Staff to the Deputy Secretary of Defense, where she was responsible for leading the executive staff, providing counsel and advice to the Deputy Secretary, and ensuring Deputy-led governance processes were aligned with key leadership priorities. Most recently, she served as Acting Deputy Director of Administration and Management within the Department of Defense.

Prior to her appointment as Chief of Staff, she was the Director of Research and Insights for Trust & Safety at Google and had previously served as Global Head of Policy Analysis at Facebook. Before her Silicon Valley work, Dr. Plumb was a senior economist at the RAND Corporation where she focused on improving measurement and evaluation of readiness and security efforts across the Department of Defense. In that capacity she served as lead author on a number of critical reports including assessing the implications of open service of Transgender Service members and review of security and suitability screening efforts.

From 2014-2015, Dr. Plumb served as the Deputy Chief of Staff to the Deputy Secretary of Energy, where she led policy processes including budget and policy reviews related to modernizing nuclear infrastructure and efforts to enhance energy sector security and resilience. Previously, she was the director of personnel and readiness at the National Security Council, where she was instrumental on executive actions on sexual assault in the military. She also served as policy advisor and Chief of Staff to the Assistant Secretary of Defense for Special Operations and Low Intensity Conflict, and as a civilian in Afghanistan conducting measurement and assessment work to support the Counterinsurgency Advisory and Assistance Team for the Commander, International Security Assistance Force.

Dr. Plumb received her Ph.D. in economics from Princeton University. Her research has covered empirical evaluations of policies aimed at reducing violence, including criminal violence, sexual assault, terrorist behavior, and sexual and intimate partner violence. At the outset of her career, she was an assistant professor at the London School of Economics and a Robert Wood Johnson Health Policy Scholar at Harvard.