November 26, 2021
Defense Primer: Department of Defense Pre-Positioned Materiel
As part of its global posture, the U.S. military maintains
CCDRs. The services rely upon the Defense Logistics
war reserve materiel (WRM), which are stocks of essential
Agency and contractor support to maintain PWRM.
items and munitions that, according to the Department of
Defense (DOD), are sufficient to attain and sustain
Several sections of Title 10, United States Code (U.S.C.)
operational objectives in DOD plans. Some of this materiel,
govern PWRM, including the following:
DOD states is designated pre-positioned WRM (or
PWRM), which is “strategically located to facilitate a
10 U.S.C. §2229. Requires the Secretary of Defense to
timely response during the initial phase of an operation.”
maintain a strategic policy on pre-positioned materiel
PWRM is stored worldwide at or near points of planned use
and to certify annually that current PWRM “meet all
in specialized facilities (i.e., ashore) and dedicated ships
operations plans, in both fill and readiness.” The
(i.e., afloat).
FY2014 National Defense Authorization Act (NDAA,
P.L. 113-66) amended §2229 to require a one-time
Why does DOD pre-position materiel?
submission of DOD’s plan to implement its strategic
The primary purpose of PWRM is to reduce military
policy.
response times and ensure timely support of operations in
10 U.S.C. §2229a. Mandates an annual report to
their initial phases, until follow-on capabilities are available
Congress, submitted prior to the submission of the
and supply chains are established. PWRM, airlift, and
President’s budget request, on the status of pre-
sealift comprise the three legs of the strategic mobility triad
positioned stocks at the end of the last fiscal year.
that enables military power projection. Pre-positioning
10 U.S.C. §229 note. Charges the Secretary of Defense
materiel reduces the demands for strategic airlift and sealift
with ensuring that service secretaries have funds to
assets by locating heavy and bulky materiel closer to the
reconstitute pre-positioned stocks in accordance with the
theater of operations. Unlike airlift and sealift, PWRM is
requirements under the strategy outlined in §2229.
not constrained by lift capacity, but comes with increased
infrastructure costs associated with storing and maintaining
Funding
stocks. Typically, personnel and a limited amount of
Two defense appropriations titles primarily fund PWRM:
equipment are transported into a theater, where they draw
Procurement and Operations and Maintenance (O&M). For
and prepare PWRM to rapidly resource deploying forces.
example, the Department of Defense Appropriations Act,
2021 (Division C of P.L. 116-260) provided $324 million
For example, in 1990-1991 during Operation Desert Shield,
within the Operation and Maintenance, Army account for
PWRM enabled the delivery of Marine Corps armored units
Army prepositioned stocks. For FY2022, DOD requested
to the Persian Gulf one month before the arrival of other
$381 million for PWRM within the Operation and
armored units shipped from the United States, according to
Maintenance, Army account. Funding amounts for the other
the Congressional Budget Office. Similarly, in 2003 during
services’ PWRM are typically included within the
Operation Iraqi Freedom, DOD made extensive use of
Mobilization budget activity within annual O&M
stocks and materiel ashore and afloat in the Middle East and
appropriations. Additionally, PWRM resources for the
Europe, to provide deployed forces essential equipment and
Army, Marine Corps , and Air Force are included annually
supplies.
as part of the European Deterrence Initiative (EDI), an
effort to reassure U.S. allies in Europe in the wake of
PWRM may be used to signal U.S. intentions. Materiel
Russia’s 2014 invasion of Ukraine’s Crimea region. Since
stored overseas may demonstrate commitment to allies and
FY2017, PWRM has been the single largest funding
partners or enhance the deterrence of potential adversaries.
category within EDI, averaging $2.3 billion over five years .
For FY2022, DOD has requested $1.2 billion for EDI
Responsibilities and Management
PWRM.
The Under Secretary of Defense for Acquisition and
Sustainment establishes and maintains a DOD-wide
Selected PWRM Programs
strategic policy for WRM and PWRM. The military
Army Pre-Positioned Stocks (APS)
departments, combatant commands, defense agencies, and
The Army considers APS materiel “a cornerstone of the
other DOD components are also responsible for issuing
Army’s ability to rapidly project power.” Army Materiel
component-specific guidance. Combatant Commanders
Command (AMC) manages APS, while Army Sustainment
(CCDRs) determine PWRM operational requirements in
Command and other AMC subordinate commands maintain
accordance with strategic guidance; the Joint Staff then
the stocks through regional Army Field Support Brigades
reviews and validates these requirements. Each military
and Battalions (See Figure 1). APS contain several
service (hereafter “service”) maintains and administers
categories of materiel:
PWRM to satisfy such requirements and meet the needs of
https://crsreports.congress.gov
Defense Primer: Department of Defense Pre-Positioned Materiel
Unit Equipment Sets contain combat equipment and
Figure 1. Selected PWRM Locations and Contents
supplies to support the Army’s force projection strategy.
Unit sets mirror Army force structure unit equipment
(i.e., brigade combat team or sustainment brigade
equipment sets).
Operational Project Stocks (OPROJ) contain
equipment above normal allowances to provide strategic
capabilities essential to the Army’s strategic deployment
strategy.
Army War Reserve Sustainment Stocks contain
materiel (including vehicles and equipment) to sustain
military operations by replacing combat losses and
consumed supplies.
APS also includes War Reserve Stocks for Allies —which
are stocks owned and funded by the United States to be
released to supported allied forces under the Foreign
Assistance Act (22 U.S.C. §2331h). These stocks are
excluded from the DOD-wide definition of PWRM.
U.S. Navy and Marine Corps Pre-Positioning
The Navy and Marine Corps rely on the afloat Maritime
Prepositioning Force (MPF) and the ashore Marine Corps
Prepositioning Program-Norway (MCPP-N) to expedite the
deployment of Marine Air-Ground Task Forces (MAGTFs).
The Marines’ Blount Island Command, a subordinate of
Marine Corps Logistics Command, maintains the MPF and
MCPP-N.
The MPF consists of two Maritime Prepositioning Ship
Squadrons (MPSRONs), operated by the Navy’s Military
Sealift Command (MSC). Each MPSRON carries unit
equipment and 30 days of supply for one brigade-sized
MAGTF when combined with an echelon of personnel,
light equipment, and combat aircraft. Each squadron is
Source: Created by CRS. MCPP-N and MPSRON information from
capable of discharging its cargo pierside, ship-to-ship, ship-
Joint Publication 4-01, The Defense Transportation System (July
to-shore, or by air. MCPP-N consists of ground equipment,
2017). APS and USAF PWRM information from U.S. Army G-4 and
munitions, and aviation support equipment to supply a
U.S. Air Force A-4 respectively.
Marine Expeditionary Brigade for 30 days.
Notes: APS-1 is designated for U.S. Army North Homeland Defense
missions or for use by overseas Army forces.
Key U.S. Air Force PWRM
Considerations for Congress
The Air Force’s PWRM is managed by Air Force Materiel
Command. Across 23 worldwide locations, Air Force
Improved Oversight of PWRM. The Government
PWRM stocks consist of dispersed ashore assets and
Accountability Office (GAO) in 2019 found “DOD
munitions necessary to initiate expeditionary operations.
continues to provide incomplete information to
Some afloat munitions stocks are also stored aboard two
Congress” and “has not fully implemented a joint
MSC vessels that are under the tactical control of the
oversight approach for managing prepositioned stock
relevant geographic CCDR. The Air Force also pre-
programs.” Congress may wish to review whether it
positions consumable items such as food and fuel, and sets
receives sufficient information to assess DOD’s pre-
of equipment designed to provide expeditionary operational
positioned stocks.
support, fuel support, damage recovery, force protection,
Annual funding. 10 U.S.C. §2229a mandates an annual
and medical capabilities. Air Force PWRM consists of three
DOD report to Congress on PWRM. In considering the
major categories of materiel:
annual budget request, Congress may evaluate whether
DOD has fully addressed statutory reporting
Common Support Equipment (CSE) sets provide
requirements.
aerospace ground equipment, vehicles, and munitions
support equipment to support initial combat operations.
Maureen Trujillo, US Air Force Fellow
Fuels Support Equipment (FSE) sets provide ground
G. James Herrera, Analyst in U.S. Defense Readiness and
and aircraft fuels support.
Infrastructure
Basic Expeditionary Airfield Resources (BEAR) sets
IF11699
provide personnel support, infrastructure, and flight line
support at forward operating sites.
https://crsreports.congress.gov
Defense Primer: Department of Defense Pre-Positioned Materiel
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to
congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress.
Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has
been provided by CRS to Members of Congress in connection with CRS’s institutional role. CRS Reports, as a work of the
United States Government, are not subject to copyright protection in the United States. Any CRS Report may be
reproduced and distributed in its entirety without permission from CRS. However, as a CRS Report may include
copyrighted images or material from a third party, you may need to obtain the permissio n of the copyright holder if you
wish to copy or otherwise use copyrighted material.
https://crsreports.congress.gov | IF11699 · VERSION 3 · NEW