Office of the Secretary of Defense

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 (listed hierarchically):

• Secretary of Defense (SecDef) and Deputy Secretary of Defense (DepSecDef)
  • Senior officials reporting directly to Secretary and Deputy
    • Executive Secretary of the Office of the Secretary of Defense (ExecSec)
    • Senior Military Assistant to the Secretary of Defense
    • General Counsel of the Department of Defense
    • Assistant to the Secretary of Defense for Public Affairs
    • Assistant to the Secretary of Defense for Privacy, Civil Liberties & Transparency
    • Chief Information Officer (DoD CIO)
    • Senior Designated Officials of SECDEF-Empowered Cross Functional Teams
  • Assistant Secretaries reporting directly to Secretary and Deputy
    • Assistant Secretary of Defense for Legislative Affairs (LA)
  • Senior officials under general supervision of the Secretary and Deputy
    • Department of Defense Office of Inspector General
  • Under Secretaries
    • Under Secretary of Defense (Comptroller)/Chief Financial Officer (C/CFO)
      • Deputy Under Secretary of Defense (Comptroller)
      • Deputy Comptroller (Program/Budget)
      • Deputy Comptroller (Budget and Appropriation Affairs)
      • Deputy Comptroller (Enterprise Financial Transformation)
      • Deputy Chief Financial Officer
      • Director, Human Capital and Resource Management
    • Under Secretary of Defense for Acquisition and Sustainment (A&S)
      • Deputy Under Secretary of Defense for Acquisition and Sustainment
      • Assistant Secretary of Defense for Acquisition
      • Assistant Secretary of Defense for Sustainment
      • Assistant Secretary of Defense for Energy, Installations, and Environment
      • Assistant Secretary of Defense for Nuclear Deterrence, Chemical & Biological Defense Policy & Programs (ND-CBD)
      • Assistant Secretary of Defense for Industrial Base Policy (IBP)
    • Under Secretary of Defense for Intelligence and Security (I&S)
      • Deputy Under Secretary of Defense for Intelligence and Security
    • Under Secretary of Defense for Personnel and Readiness (P&R)
      • Deputy Under Secretary of Defense for Personnel and Readiness
      • Assistant Secretary of Defense for Health Affairs (HA)
      • Assistant Secretary of Defense for Manpower and Reserve Affairs (M&RA)
      • Assistant Secretary of Defense for Readiness and Force Management
      • Executive Director, Defense Human Resources Activity (DHRA)
      • Executive Director, Force Resiliency
      • Executive Director, Personnel and Readiness
    • Under Secretary of Defense for Policy (P)
      • Deputy Under Secretary of Defense for Policy
      • Assistant Secretary of Defense for Indo-Pacific Security Affairs (IPSA)
      • Assistant Secretary of Defense for Special Operations and Low-Intensity Conflict
      • Assistant Secretary of Defense for Homeland Defense and Hemispheric Affairs (HD&HA)
      • Assistant Secretary of Defense for International Security Affairs (ISA)
      • Assistant Secretary of Defense for Special Operations and Low Intensity Conflict (SO&LIC)
      • Assistant Secretary of Defense for Space Policy
      • Assistant Secretary of Defense for Strategy, Plans, and Capabilities
    • Under Secretary of Defense for Research and Engineering
      • Deputy Under Secretary of Defense for Research and Engineering
      • Assistant Secretary of Defense for Critical Technologies
      • Assistant Secretary of Defense for Science and Technology
      • Assistant Secretary of Defense for Mission Capabilities
      • Chief Digital and Artificial Intelligence Office
  • Directors
    • Director of Administration and Management (DA&M)
    • Director of Cost Assessment and Program Evaluation (CAPE)
    • Director of Net Assessment
    • Director, Defense Innovation Unit
    • Director, Operational Test and Evaluation (DOT&E)

Former elements

• Assistant Secretary of Defense for Networks and Information Integration (NII) - now the DoD Chief Information Officer
• Defense Prisoner of War/Missing Personnel Office (DPMO)

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 (OSD) 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 (DepSecDef), all five Under Secretaries of Defense (USDs), and all Assistant Secretaries of Defense (ASDs), as well as any officials specifically designated in U.S. Code have historically been considered Presidentially-Appointed, Senate-Confirmed (PAS) 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 (DUSDs)—"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 (i.e., "first assistants"), one for each Under Secretary of Defense.

The NDAA (National Defense Authorization Act) of fiscal year 2010 gave the Department of Defense until January 1, 2011, to eliminate or redesignate all other Deputy Under Secretaries (DUSDs) who are not Principal Deputy Under Secretaries of Defense (PDUSDs). 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 (Presidentially-appointed, Senate-confirmed) 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.

:* Director for Defense Intelligence = DDI, DUSD = Deputy Under Secretary of Defense, ASD = Assistant Secretary of Defense, DASD = Deputy Assistant Secretary of Defense

References

References

1. "Executive Order: RESTORING THE UNITED STATES DEPARTMENT OF WAR September 5, 2025".
2. "The Executive Secretary, Office of the Secretary of Defense". [[United States Department of Defense]].
3. "Chief Information Officer". [[United States Department of Defense]].
4. "Office of Force Resiliency". [[United States Department of Defense]].
5. Title X, Subtitle A, Part 1, Chapter 4, https://www.law.cornell.edu/uscode/usc_sup_01_10_10_A_20_I_30_4.html
6. ODAM. (April 2010). "Revised Organizational Structure for the Office of the Secretary of Defense". Department of Defense.
7. 111th Congress. (October 28, 2009). "National Defense Authorization Act for Fiscal Year 2010". Government Printing Office.
8. Title IX, Subtitle A, Section 901, Part b, Section 4, http://www.gpo.gov/fdsys/pkg/BILLS-111hr6523enr/pdf/BILLS-111hr6523enr.pdf
9. ODAM. (April 2010). "Revised Organizational Structure for the Office of the Secretary of Defense". Department of Defense.