John Hopkins University Applied Physics Laboratory, Laurel, Maryland (HQ033419D0006), has been awarded a $637,564,048 modification to an indefinite-delivery/indefinite-quantity, cost-plus-fixed-fee contract to provide support to the Office of the Secretary of Defense to establish and maintain essential engineering, research, development, test and evaluation, and analytic capabilities using operational knowledge of the national defense, intelligence, and security environments. These services and capabilities are essential to a variety of critical Department of Defense programs that are managed by various components and offices internal and external to the Office of the Secretary of Defense, the Executive and Legislative Branch, and the Intelligence Community. The work will be performed in contractor facilities in Alexandria, Virginia; Laurel, Maryland; and at U.S. government facilities within the National Capital Region. This action increases the contract ceiling from $873,000,000, to $1,510,564,048. The estimated contract completion date is March 25, 2024. Washington Headquarters Services, Arlington, Virginia, is the contracting activity.