Defense Primer: Department of Defense Maintenance Depots

Title 10, United States Code (U.S.C.) §2464 requires the Department of Defense (DOD) to "maintain a core logistics capability that is government-owned and government-operated [GOGO]… to ensure a ready and controlled source of technical competence and resources necessary to ensure effective and timely response to a mobilization, national defense contingency situations, and other emergency requirements." This capability resides in DOD maintenance depots, which perform depot-level maintenance and repair (defined by 10 U.S.C. §2460 as "material maintenance or repair requiring the overhaul, upgrading, or rebuilding of parts, assemblies, or subassemblies, and the testing and reclamation of equipment"). These GOGO facilities, together with certain government-owned, contractor-operated (GOCO) facilities, are collectively referred to as the organic industrial base, or OIB. The Government Accountability Office (GAO), in a 2019 report (GAO-19-242), described these depots as "crucial to maintaining military readiness by ensuring that the services can regularly repair critical weapon systems and return them to the warfighter for their use in training and operations."

Although each military department (MILDEP) manages and resources the depots that service its weapon systems and equipment, the Under Secretary of Defense for Acquisition and Sustainment (USD (A&S)) is responsible for DOD-wide maintenance policy direction and oversight. In addition to repairing and maintaining military systems, each MILDEP's depots serve as repositories for technical data, testing equipment, and unique tooling and design capabilities. Depending on the types of activities supported, DOD may designate facilities performing depot functions as logistics complexes, shipyards, readiness centers, or logistics bases. Depot-level maintenance and repair activities also encompass certain types of software maintenance, but do not include major upgrades, the procurement of parts for safety modifications, or the nuclear refueling and defueling of aircraft carriers.

Organization and Management

Among OIB GOGO facilities, Congress has designated 21 "covered depots" for special oversight under 10 U.S.C. §2476 due to their importance in Chairman, Joint Chiefs of Staff strategic and contingency plans. Covered depots currently include 18 depots, logistics complexes, shipyards, readiness centers, and logistics bases, as well as 3 Army arsenals with depot maintenance capabilities. Together, they employ a workforce of over 80,000 government civilians (Figure 1).

Figure 1. DOD Covered Depots (10 U.S.C. §2476)

Source: CRS adaptation of GAO graphic ("Military Depots: DOD Strategy for Addressing Deteriorating Facilities and Equipment Is Incomplete," GAO-22-105009).

Army Covered Depots

Army Materiel Command (AMC) operates the following nine Army sites, each of which services particular systems.

• Anniston Army Depot (Anniston, AL): Tracked and wheeled ground combat vehicles; small caliber weapons; towed and self-propelled artillery; and rail equipment.
• Corpus Christi Army Depot (Corpus Christi, TX): Rotary wing aircraft.
• Letterkenny Army Depot (Chambersburg, PA): Air and missile defense; and precision fires systems.
• Red River Army Depot (Texarkana, TX): Tactical wheeled vehicles.
• Tobyhanna Army Depot (Tobyhanna, PA): Command, control, communications, computers, intelligence, surveillance, and reconnaissance systems; electronics, avionics, and missile guidance/control systems.
• Rock Island Arsenal (Rock Island, IL): Joint Manufacturing and Technology Center; Joint Munitions Command; and Army Sustainment Command.
• Pine Bluff Arsenal (Pine Bluff, AR): Chemical, biological, radiological, and nuclear (CBRN) systems; and specialized ammunition.
• Watervliet Arsenal (Watervliet, NY): Cannons, mortars, and associated components.
• Tooele Army Depot (Tooele, UT): Equipment for handling, maintaining, and modifying ammunition.

Air Force Covered Depots

Air Force Materiel Command's Air Force Sustainment Center (AFSC) operates the following three air logistics centers, each of which services particular airframes and systems.

• Ogden Air Logistics Center (Hill Air Force Base, UT): F-35; F-22; F-16; A-10; C-130; T-38; Minuteman III Intercontinental Ballistic Missiles; and landing gear.
• Oklahoma City Air Logistics Center (Tinker Air Force Base, OK): KC-46; KC-135; B-1B; B-52; E-3; E-6; various aircraft engines; and software.
• Warner Robins Air Logistics Center (Warner Robins, GA): F-15; C-5; C-130; C-17; and various special operations forces aircraft.

Navy Covered Depots

Naval Sea Systems Command (NAVSEA) and Naval Air Systems Command (NAVAIR) manage covered Navy shipyards and fleet readiness centers, respectively.

NAVSEA operates the following four shipyards, each of which services a variety of ships and submarines.

• Norfolk Naval Shipyard (Portsmouth, VA)
• Pearl Harbor Naval Shipyard and Intermediate Maintenance Facility (Pearl Harbor, HI)
• Portsmouth Naval Shipyard (Kittery, ME)
• Puget Sound Naval Shipyard and Intermediate Maintenance Facility (Bremerton, WA)

NAVAIR operates the following three fleet readiness centers, each of which services particular Navy and Marine Corps airframes and systems.

• Fleet Readiness Center East (Cherry Point, NC): MV-22B; F/A-18 Hornets and Super Hornets; F-35B; UH-1N; CH-53E; and AV-8B.
• Fleet Readiness Center Southeast (Jacksonville, FL): P-8; P-3; H-60; F/A-18 Super Hornets; various naval aviation weapon systems; aeronautical components; and life support systems.
• Fleet Readiness Center Southwest (North Island, CA): AV-8B; E-2; H-60; and UH-1N.

Marine Corps Covered Depots

Marine Depot Maintenance Command operates the following two logistics bases, each of which services a variety of ground combat and combat support equipment.

• Marine Corps Logistics Base Albany (Albany, GA)
• Marine Corps Logistics Base Barstow (Barstow, CA)

Funding

Title 10 U.S.C. §2460 defines depot-level maintenance without regard to which appropriation funds the activity. DOD reported an FY2025 Operation and Maintenance (O&M) budget request of $40.6 billion for depot maintenance activities across all armed services and components, compared to $38.9 billion estimated for FY2024. The FY2025 request reportedly satisfies 87.1% of total estimated depot maintenance requirements, including 52.7% of Army requirements; 92.5% of Navy requirements; 76.5% of Marine Corps requirements; 86.8% of Air Force requirements; and 81.0% of Space Force requirements. This depot maintenance request does not include requests for Military Construction appropriations related to depot maintenance facilities, or Procurement appropriations related to "depot maintenance capital equipment unique to newly introduced weapon systems" and weapon system modifications.

Relevant Statutory Requirements

Title 10 U.S.C. §2460 explicitly provides a role for depot-level maintenance and repair performed by private-sector contractors. Title 10 U.S.C. §2466 prohibits DOD from spending more than 50% of its annual depot-level maintenance funds on contracting with nonfederal entities in a given fiscal year (sometimes referred to as the 50-50 rule). DOD is also barred by 10 U.S.C. §2472 from setting managerial ceilings on the total number of depot personnel; rather, the statute requires the department to manage personnel levels "solely on the basis of the available workload and the funds made available for such depot-level maintenance and repair."

Title 10 U.S.C. §2476 establishes capital investment and congressional reporting requirements for the 21 covered depots. Each MILDEP must annually invest at least 8% of the total value of its depot workload (averaged over the previous three years) into the capital budgets of its depots. Of this annual investment, 25% must be used for facilities sustainment, restoration, and modernization (FSRM). In addition, DOD must annually submit a report to the congressional defense committees detailing the MILDEPs' depot investments, including benchmarks, funded workloads, and any impediments.

Considerations for Congress

Regional Sustainment Framework. DOD's 2024 Regional Sustainment Framework prioritizes "co-sustainment" relationships with industry partners, requiring adaptive sustainment planning and continuous monitoring to ensure compliance with the 50/50 rule of 10 U.S.C. §2466. Congress may consider assessing these efforts, including the magnitude of industry participation from NATO and "major non-NATO ally" countries per the Overseas Workload Program (10 U.S.C. §2349).

Resourcing maintenance depots. DOD's National Defense Industrial Strategy Implementation Plan for FY2025 states that Army depot modernization "will substantially increase future capacity, efficiency, and capability in both ammunition production and maintenance activities." Congress may oversee the Army's execution of this plan, and might consider whether further modifications to investment requirements and priorities could improve the condition of depot infrastructure.