Office of the Secretary of Defense


The Office of the Secretary of Defense is a headquarters-level staff of the United States Department of Defense. It is the principal civilian staff element of the [United States Secretary of Defense (United States)|Secretary of Defense|U.S. United States Secretary of Defense|secretary of defense], and it assists the secretary in carrying out authority, direction, and control of the Department of Defense in the exercise of policy development, planning, resource management, fiscal, and program evaluation responsibilities. OSD is the secretary of defense's support staff for managing the Department of Defense, and it corresponds to what the Executive Office of the President of the U.S. is to the U.S. president for managing the whole of the Executive branch of the federal government. In 2025, President Donald Trump authorized "Office of the Secretary of War" as a secondary title for the Office of the Secretary of Defense, permitted in ceremonial and non-statutory contexts; only an act of Congress can change the name of the office associated with the department. The current Secretary of Defense is Pete Hegseth.
OSD includes the immediate offices of the secretary and the deputy secretary of defense, as well as the under-secretary of defense for research and engineering; under-secretary of defense for acquisition and sustainment; under-secretary of defense for policy; under-secretary of defense ; under-secretary of defense for personnel and readiness; and under-secretary of defense for intelligence & security. All of these positions are presidential appointments which require U.S. Senate confirmation, as do each of their sole deputies. Other positions include the assistant secretaries of defense, assistants to the secretary of defense, General Counsel, Director, Operational Test and Evaluation, Director of Administration and Management, and other staff offices that the secretary establishes to assist in carrying out their assigned responsibilities.
WWW defense.gov/osd

Composition of OSD

The secretary and deputy secretary manage several under secretaries, each of whom in turn manages several assistant secretaries of defense. There are also several special officers reporting directly to the Secretary of Defense.
Major elements of OSD :

Former elements

Major reorganizations

The composition of OSD is in a state of consistent flux, as Congress and DoD routinely create new offices, redesignate existing ones, and abolish others.

Obama administration changes

During the Obama administration, Congress had sought to clarify the organization of the Office of the Secretary of Defense and worked with the Department of Defense to move toward a standardization of official naming conventions. Many Defense officials, including the Deputy Secretary of Defense, all five Under Secretaries of Defense, and all Assistant Secretaries of Defense, as well as any officials specifically designated in U.S. Code have historically been considered Presidentially-Appointed, Senate-Confirmed officials, requiring consent of the Senate before the appointee operates in an official capacity. In a March 2009 letter, Senator Carl Levin, Chairman of the Senate Armed Service Committee, wrote that the Defense Department was apparently exercising the authority to appoint other significant officials—termed Deputy Under Secretaries of Defense —"without statutory authorization, without limitation, and without Senate confirmation." Levin was "concerned that the proliferation of DUSDs at multiple levels of the organization could muddy lines of authority and may not be in the best interest of the Department of Defense." Subsequent legislation established five Senate-confirmed Principal Deputies, one for each Under Secretary of Defense.
The NDAA of fiscal year 2010 gave the Department of Defense until January 1, 2011, to eliminate or redesignate all other Deputy Under Secretaries who are not Principal Deputy Under Secretaries of Defense. The FY11 National Defense Authorization Act extended this deadline to January 1, 2015. During that time, the Secretary was allowed, at his or her discretion, to appoint within the Office of the Secretary of Defense five additional non-PAS Deputy Under Secretaries of Defense (DUSDs) beyond the five statutory PAS-PDUSDs. The USD(I)–Intelligence–appears to be maintaining at least three non-PAS DUSDs, although they have been renamed. The USD (AT&L)–Acquisition, Technology, & Logistics–has maintained the non-PAS DUSD for Installations and Environment, though the FY11 NDAA recommended merging this post with the newly created ASD for Operational Energy Plans and Programs. The USD(P) has maintained a non-PAS DUSD for Strategy, Plans, and Forces, even though the FY11 NDAA recommended eliminating this position.
Nevertheless, several positions were redesignated or eliminated during the Obama administration, pursuant to statutory language contained in the National Defense Authorization Acts of FY10 and FY11. and subsequent internal DoD reports.
Previous Office TitleNew Office TitleReports ToRequires Senate Confirmation?
New positionASD for AcquisitionUSD(AT&L)Yes
DUSD for Industrial PolicyDASD for Manufacturing and Industrial BaseASD for AcquisitionNo
DUSD for Logistics and Material ReadinessASD for Logistics and Material ReadinessUSD(AT&L)Yes
Director of Operational Energy Plans and ProgramsASD for Operational Energy Plans and ProgramsUSD(AT&L)Yes
Assistant to the Secretary of Defense for Nuclear and Chemical and Biological Defense ProgramsASD for Nuclear, Chemical, and Biological Defense ProgramsUSD(AT&L)Yes
Director of Defense Research and EngineeringASD for Research and Engineering (R&E)USD(AT&L)Yes
Director of Developmental Test and EvaluationDASD for Developmental Test and EvaluationASD(R&E)No
Director of Systems EngineeringDASD for Systems EngineeringASD(R&E)No
New positionASD for Readiness and Force Management USD(P&R)Yes
DUSD for Civilian Personnel PolicyDASD for Civilian Personnel PolicyASD for Readiness and Force Management No
DUSD for Military Community and Family PolicyDASD for Military Community and Family PolicyASD for Readiness and Force Management No
DUSD for Military Personnel PolicyDASD for Military Personnel PolicyASD for Readiness and Force Management No
DUSD for ReadinessDASD for ReadinessASD for Readiness and Force Management No
DUSD for Wounded Warrior Care and Transition PolicyDASD for Wounded Warrior Care and Transition PolicyASD for Readiness and Force Management No
DUSD for Joint & Coalition Warfighter SupportDDI for Warfighter Support & OperationsUnder Secretary of Defense for IntelligenceNo
DUSD for Technical Collection & Analysis and HUMINT, Counterintel & SecurityDDI for Intelligence & SecurityUnder Secretary of Defense for IntelligenceNo
DUSD for Portfolio Programs & ResourcesDDI for Military Intelligence Program & PlanningUnder Secretary of Defense for IntelligenceNo
DUSD for Science and TechnologyEliminated-n/a
DUSD for Advanced Systems and ConceptsEliminated-n/a