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Philip T. Calbos

Principal Assistant Deputy Administrator for Defense Programs

Phil Calbos serves as the Principal Assistant Deputy Administrator for Defense Programs for NNSA. He leads a team in directing the Stockpile Stewardship Program, which is responsible for maintaining the safety, security, and reliability of the nation’s nuclear weapons stockpile.

Previously, he served for almost four years as the Branch Chief for Military Operations, Personnel and Support in the Office of Management and Budget’s (OMB) National Security Division. He also served as a program examiner at OMB with responsibility for a diverse set of programs covering Department of Defense investment, operations, and personnel initiatives, as well as all programs managed by NNSA. He served in the U.S. Army as an infantry officer, the U.S. Army National Guard, and the private sector. 

Calbos graduated from the United States Military Academy at West Point with a bachelor of science in history. He earned a master’s degree in international relations from the Johns Hopkins University’s Nitze School of Advanced International Studies and a masters of national security strategy from the National War College at Fort McNair in Washington.