How many Under Secretaries of Defense assist the Secretary of Defense?

• A. Four
• B. Six
• C. Five
• D. Seven

Answer: (B)

The Secretary of Defense is supported by six Under Secretaries of Defense, each heading a major civilian area within the department. These roles cover Policy, Comptroller, Acquisition and Sustainment, Personnel and Readiness, Research and Engineering, and Intelligence and Security. Together with the Deputy Secretary, they form the top civilian leadership directly assisting the Secretary, providing policy guidance, budget oversight, and program management across their domains. The number is fixed by the department’s organizational design, aligning with six distinct portfolios that require senior civilian leadership. Having fewer would leave a domain without its own Under Secretary, while more would add a portfolio that isn’t part of the current structure, so six is the best fit.