The Under Secretary of Defense (Comptroller)/Chief Financial Officer, abbreviated USD(C)/CFO, is a high level civilian official in the United States Department of Defense. The Under Secretary of Defense (Comptroller) is the principal staff assistant and adviser to both the Secretary of Defense and the Deputy Secretary of Defense for all budgetary and fiscal matters, including the development and execution of the Defense Department's annual $500 billion budget. The Under Secretary is appointed by the President and confirmed by the United States Senate to serve at the pleasure of the President.