What GAO Found The U.S. Navy has not fully mitigated attack submarine fleet maintenance and other challenges affecting readiness. Over the last 10 years, the U.S. Navy has lost more than 15,000 operational days due to maintenance delays and idle time on active attack submarines. These delays resulted in an estimated $3.4 billion in costs to sustain crews and submarines that provided no operational capability. U.S. Navy Attack Submarine Depot Maintenance Delays, Length of Depot Maintenance Periods, and Idle Time, Fiscal Years 2016–2025 Lost operational days include delays completing depot maintenance and active idle time. Active idle time describes a period when an attack submarine and its crew must remain pier-side because they are no longer certified to conduct normal operations and cannot be inducted into a maintenance period. In addition to lost operational days, the Navy faces significant challenges with managing inactive idle time for attack submarines. Inactive idle time describes when an attack submarine designated for decommissioning cannot be inducted into a dry dock in a shipyard. As a result, the submarine and its crew must remain pier-side until a shipyard has the capacity in a dry dock to defuel their nuclear reactor. While the U.S. Navy has made recent progress in reducing active idle time, inactive idle time for submarines has grown and is projected to worsen. Without mitigation, 15 attack submarines will enter inactive idle time from fiscal year 2026 through fiscal year 2030—during which time the Navy could incur more than 14,000 days of inactive idle time and $3.1 billion in costs to operate and support these inactive submarines. The U.S. Navy has not fully evaluated alternative options to more efficiently decommission attack submarines and develop and implement an inactivation plan that could allow them to reduce inactive idle time for crews and save billions. Why GAO Did This Study According to the U.S. Navy, its 44 attack submarines, as of fiscal year 2025, provide the United States an asymmetric advantage to gather intelligence undetected and attack enemy targets, among other missions. These capabilities make attack submarines some of the most requested assets by the global combatant commanders. House Report 118-529 includes a provision for GAO to assess the readiness and availability of the U.S. Navy’s attack submarine fleet. This report discusses the extent to which the Navy has effectively maintained its attack submarine fleet and has mitigated any challenges. GAO analyzed U.S. Navy attack submarine maintenance data from fiscal years 2016 through 2025, reviewed U.S. Navy documentation, and interviewed officials. This report is a public version of a classified report GAO issued July 16, 2026. GAO omitted information the Department of Defense deemed classified or sensitive, such as attack submarine operational availability and how the U.S. Navy’s approach to attack submarine force generation compares to strategic competitors’ approaches.

What GAO Found The U.S. commercial space sector has grown rapidly over the last few years, and offers data and data-related services—such as the imagery below—that the Department of Defense (DOD) uses to maintain national security. National Reconnaissance Office Purchased Commercial Images of Chinese Aircraft Carriers Within the Space Force, the Joint Commercial Operations Cell (JCO)—the main organization that buys data and services—purchased various types of data and services through the contractor-operated Global Data Marketplace. JCO expended $76.8 million on data and services from the marketplace from January 2023 through September 2025. These purchases supported missions including space domain awareness and tactical surveillance, reconnaissance and tracking. The National Reconnaissance Office (NRO) and National Geospatial-Intelligence Agency (NGA) also purchased various forms of commercial imagery and commercial analytic products, respectively, from fiscal years 2021 through 2025. Some Space Force officials told GAO about challenges they have faced related to purchasing and using commercial space data such as licensing costs, perceived use restrictions, and concerns over long-term access to the data. These challenges led to hesitation to purchase and use commercial data among these potential users. JCO leads an informal working group to discuss and coordinate current and future commercial space data purchases made by various federal organizations. This working group meets monthly and coordinates purchases. GAO found that many of the challenges reported by Space Force officials could have been addressed with discussions at the working group, but the Space Force officials were not part of the working group and information about the working group is not widely available. JCO officials said they would be supportive of information about the working group being listed to increase awareness. Increased communication about the working group could lead to additional Space Force and other officials engaging in discussions that could address perceived issues and improve the use of commercial space data and services for national security purposes. Why GAO Did This Study Threats to DOD’s space assets from strategic competitors have grown substantially in number and intensity. DOD is working to integrate commercial space solutions, such as data and services, to mitigate these threats as well as enhance its capabilities. Members of Congress included a provision in a committee report for GAO to review DOD’s purchases of commercial space data and services. GAO’s report examines (1) the types of commercial space data and data-related services DOD purchased from fiscal years 2021 through 2025, and (2) the extent to which DOD faced challenges when purchasing and using these data and related services. GAO analyzed expenditures for orders JCO made through the Global Data Marketplace from January 27, 2023, to September 30, 2025. In the case of NRO and NGA, GAO obtained unclassified summary information. GAO attended an informal working group meeting led by JCO, reviewed the contract for the marketplace, and interviewed relevant DOD agency officials and contractor representatives. “Commercial space data” are data collected from commercial assets, and “commercial space data-related services” is the range of services for commercial space data.

What GAO Found In school year 2024–2025, about 10 percent of the approximately 60,000 K-12 students attending Department of Defense Education Activity’s (DODEA) schools full time received strategic instruction. This is short-term extra help in a small group setting (see figure). About 5 percent had a “specific learning disability” (SLD). SLDs are a group of disorders, such as dyslexia and dyscalculia, related to understanding language or doing mathematical calculations. The number of DODEA students with SLDs increased 29 percent from school years 2018–2019 through 2024–2025. DODEA Instructional Materials for Students with Literacy and Math Deficits Most staff in the 11 selected schools GAO visited—in five districts that serve 63 percent of DODEA students with SLDs—outlined obstacles to timely identifying students needing strategic instruction or special education for SLDs. These included limited screening tools, challenges with submitting complete student referrals for strategic instruction and special education, and delayed special education evaluations. For example, at nine of 11 schools, staff said they needed more or better screening tools to identify students. DODEA’s screening tools do not directly assess elementary school students’ foundational phonics skills, which help identify reading deficits. They also are not available for all students. These limitations make it difficult to identify students who are behind grade level when they arrive at a school—which is important given DODEA’s highly mobile population. In July 2026, DODEA officials said that they procured universal screening tools for all grades and plan to start administering them in late 2026. When implemented, these tools will provide key data to fill gaps in identifying students’ needs and connect them to support. DODEA staff at all 11 schools we visited also cited obstacles to helping students meet their literacy and math goals. These included strategic instruction and special education teachers not receiving professional learning relevant to their roles, not having adequate access to data on students’ grades, and varied practices across DODEA schools that result in eligible students not receiving needed help to meet grade-level expectations. For example, during GAO’s interviews, 32 of 44 strategic instruction and special education teachers rated their professional learning opportunities as “bad” or “very bad.” Further, staff at all 11 schools said they wanted teachers to be able to provide input on needed professional learning—for example, opportunities focused on identifying students with literacy and math deficits and SLDs. DODEA guidelines say that professional learning should advance teachers’ ability to apply acquired knowledge and skills targeted to their role. Asking for and acting on teacher feedback would help DODEA advance teachers’ ability to apply the skills needed to help students with literacy and math deficits and SLDs meet their learning goals. Why GAO Did This Study Students in military families—many of whom attend DODEA schools—face unique challenges due to frequent moves. DODEA families have raised concerns about access to literacy and math supports and special education services. Research shows that instruction tailored to students’ needs can improve academic outcomes and reduce the number of students referred to special education. The Joint Explanatory Statement accompanying the 2025 National Defense Authorization Act includes a provision for GAO to examine services for DODEA students with literacy and math deficits and SLDs. GAO examined (1) the number of students receiving strategic instruction or having an SLD, (2) the extent DODEA provides guidance and tools to identify these students, and (3) the extent DODEA supports teachers in helping students. GAO analyzed DODEA data from school years 2018-2019 through 2024-2025 on student enrollment and reviewed relevant federal laws and DOD policies. GAO conducted in-person site visits to schools in five of nine DODEA districts, selected for variation in number of students with SLDs, among other things. GAO interviewed DODEA officials and held 47 group interviews with teachers, administrators, and other stakeholders. GAO also administered a nongeneralizable opt-in online questionnaire to parents of DODEA students with SLDs.

What GAO Found Selected field offices in Department of Energy's (DOE) Office of Environmental Management (EM) have taken steps to evaluate effectiveness of contractor assurance systems (CAS) in accordance with DOE policy, though neither DOE nor EM have defined effectiveness or specified evaluation criteria. The basis on which the selected field offices made their respective effectiveness determinations was unclear (see table). In addition, all selected field offices reported examples of poor CAS performance and recurring issues that undermined the reliability of the effectiveness determinations. How Selected EM Field Offices Assessed Contractor Assurance System (CAS) Effectiveness Selected field office CAS effectiveness determination Was CAS effectiveness defined? Were effectiveness criteria included? Hanford Effective No No Idaho Effective No No Los Alamos Not determined No No Source: GAO analysis of Office of Environmental Managment (EM) information. | GAO-26-107850 Hanford: The field office reported that the contractor demonstrated poor work planning and conduct of operations, requiring EM to formally request a corrective action plan in several areas. Also, the contractor’s review of issues between January 2022 and October 2023 found that it improperly closed and insufficiently documented nearly 40 percent of sampled issues at the two highest significance levels. These are issues that should not recur or are typically related to misuse of resources, according to field office officials. Idaho: The field office reported that the number and severity of conduct of operations and maintenance-related abnormal events indicated a need for improved rigor and discipline in operations. The contractor noted trends that showed a continuing need for attention to detail and personnel awareness. Additionally, the contractor reported 15 radiological events over 8 months that put personnel at risk of radiological overexposure. Los Alamos: The field office identified concerns with CAS effectiveness, including that the contractor did not have effective processes for self-identifying significant issues. Furthermore, a widespread breakdown of the contractor’s training and qualification program in 2023 resulted in a stop work order—an indicator that a CAS is not functioning well, according to a field office official. The stop work order resulted in a 90-day delay for nuclear waste disposal and environmental remediation efforts. Without defining what constitutes an effective CAS—including establishing specific, measurable evaluation criteria—field offices do not have concrete guidelines for evaluating CASs and their determinations may be less informative or meaningful as a result. Additionally, the lack of a clear definition hinders EM’s ability to hold the contractor accountable, and EM cannot be assured that contractors can effectively and efficiently manage risks. Why GAO Did This Study EM relies on contractors to execute its mission to clean up contaminated sites from decades of nuclear-related activities. EM expects certain contractors to design and use a CAS—management systems and processes to oversee their own performance, identify and report potential problems, and take actions to prevent their recurrence. According to EM policy, EM is to rely on outcomes and information from CASs to inform and optimize their respective oversight programs. However, in 2024, an independent entity found that contractors inadequately managed issues, leading to compromised safety and increased likelihood of significant consequences. Senate Report 118-58, accompanying a bill for the National Defense Authorization Act for Fiscal Year 2024, includes a provision for GAO to examine EM’s oversight of contractors’ assurance systems. This report examines the extent to which EM has evaluated the effectiveness of selected CASs. GAO reviewed EM and contractor documents, conducted a site visit, and interviewed DOE officials and contractors. GAO selected three contracts and associated CASs, contractors, and field offices to review based on factors including contract value and purpose.

What GAO Found Qualified Opportunity Zones (Zone)—low-income census tracts nominated by governors and designated by the Department of the Treasury—have lower incomes and higher poverty than other census tracts. The law commonly known as the One Big Beautiful Bill Act (OBBBA) changed the eligibility criteria for Zone designation, which resulted in fewer eligible tracts for future selection. Stakeholders, including some states and subject-matter specialists, reported that this may allow better targeting of the tax incentive to the most economically distressed areas. Stakeholders reported the incentive is primarily funding real estate development. According to state officials and Qualified Opportunity Fund representatives, Zones that received investment tended to be in urban locations and have access to infrastructure and community support. Tax benefits for investments in newly defined rural Zones could drive investment in those areas, but stakeholders were uncertain about the extent. States were mostly unsure about the effects of investment on outcomes, but about 20 percent of states cited increased job creation and housing as effects. States’ Views of Effects of Opportunity Zone Investment on Selected Outcomes in Their States, 2025 OBBBA’s changes to the tax incentive may mitigate some challenges state officials and fund representatives identified with the original incentive. For example, new requirements for funds and for Treasury to report on characteristics of investments will allow the government and the public to better understand investment and its potential economic effects in Zones. Further, the additional time the act provides for states to prepare to nominate census tracts to be designated as Zones may help states make informed selections. Why GAO Did This Study Congress created the Opportunity Zone tax incentive to spur investment in economically distressed communities. Taxpayers who invest in Qualified Opportunity Funds—funds organized for the purpose of investing in Zones—are eligible for certain tax benefits, such as deferral of taxes on the invested amount. These funds held more than $108 billion in assets as of the end of 2024. OBBBA made the incentive permanent and introduced a new category of Zones comprised entirely of a rural area with different potential tax benefits. GAO was asked to review the Opportunity Zone tax incentive. This report describes (1) Zones’ characteristics and how the revised incentive under OBBBA could affect future Zones’ characteristics; (2) the experiences of states, Qualified Opportunity Funds, and other stakeholders with the original incentive and how the revised incentive may affect future investment activity; (3) stakeholders’ awareness of the original incentive’s effects on communities; and (4) the changes to the incentive introduced by OBBBA and the extent to which they address previous challenges. GAO analyzed Census data on tracts designated as Zones and those eligible for the second round of Zone designation, analyzed data from a nongeneralizable sample of 16 Qualified Opportunity Funds, interviewed fund representatives, conducted site visits to investments from seven selected funds, surveyed all states and U.S. territories, and interviewed selected state officials and subject-matter specialists knowledgeable about the tax incentive from five organizations. GAO also reviewed documents and interviewed federal agency officials. For more information, contact Jessica Lucas-Judy at lucasjudyj@gao.gov.

What GAO Found The Department of Defense (DOD) does not request full funding of identified needs for installation maintenance or major improvement projects for facilities. This shortage has led to an estimated $285 billion of maintenance backlogs in fiscal year 2025. Due to competing budget priorities, DOD set a goal to fund 90 percent of its maintenance needs, but GAO found that the military services continue to fall short of this goal by funding about 80 percent of these needs. DOD has not fully determined the risks to its mission and to the quality of life of its personnel as a result of not meeting its funding goal. Fully determining and communicating these risks would provide better information to DOD and Congress to weigh budget priorities. Examples of Facility Deterioration at Selected Military Installations due to Deferred Maintenance, Resulting in Damage, Corrosion, and Suspected Mold DOD also faces challenges in hiring and retaining key maintenance workers, which are critical for maintaining facilities. According to officials, challenges include hiring in remote and isolated locations; employment competition with the private sector; and federal hiring, pay, and work eligibility practices, which have been exacerbated by recent workforce reductions and the subsequent hiring freeze. However, GAO found that the military departments have not fully identified the extent of maintenance workforce shortages or developed strategies to address these challenges. Doing so would better position department and service leadership to ensure that they have the skilled workforce to address maintenance needs. Reliable information is important for DOD to effectively prioritize needed maintenance and improvement projects in light of insufficient funding and workforce challenges. However, GAO found that standards for maintenance vary across the services, limiting effective department-wide decision-making. Additionally, installations rely on maintenance work order data systems to respond to identified maintenance needs. However, GAO found that tracking is limited and that the data within those systems are generally unreliable for determining the overall effectiveness of maintenance performed across installations and the services. With improved maintenance information, DOD would be better positioned to take steps to strengthen oversight to improve the department’s vast portfolio of infrastructure and ensure that risks to mission and quality of life are reduced. Why GAO Did This Study DOD had over 736,000 facilities worldwide, with an estimated value of $2.6 trillion as of fiscal year 2025. Managing real property has been on GAO’s High-Risk List since 2003. GAO has reported that better management of the federal government’s real property portfolio is needed to collect reliable real property information and improve the condition of federal facilities, including DOD facilities, and could save billions of dollars. Senate Report 118-58 and House Report 118-125 contained provisions for GAO to assess DOD’s installation maintenance practices. Specifically, this report examines the extent to which DOD has (1) fully funded its facility maintenance and improvement needs; (2) determined the sufficiency of its maintenance workforce; and (3) developed the needed standards, reliable information, and oversight to manage installation maintenance. GAO analyzed DOD policies, budgets, maintenance data, and other documentation; interviewed DOD officials, including installation officials and maintenance customers from a non-generalizable sample of eight installations.

What GAO Found As of August 2026, EXIM was not monitoring the end use of any dual-use export because all such transactions had been repaid in full. EXIM did not finance any new exports under its dual-use authority in fiscal year 2025, according to EXIM authorization data and EXIM officials. Why GAO Did This Study The mission of the Export-Import Bank of the United States (EXIM) is to help support American jobs by facilitating the export of U.S. goods and services and financing imports. In 1994, Congress passed legislation authorizing EXIM to facilitate the financing of U.S. exports of defense articles and services with both civilian and military applications, provided that the bank determines such dual-use items are nonlethal and primarily meant for civilian end use. Included in the same act was a provision for GAO, in consultation with EXIM, to report annually on the end uses of dual-use exports financed by EXIM during the second preceding fiscal year. This report (1) examines the status of EXIM's monitoring of dual-use exports that it continued to finance in fiscal year 2024, as of August 2026, and (2) identifies any new dual-use exports that EXIM financed in fiscal year 2025. To address these objectives, GAO reviewed EXIM documentation and data on dual-use exports and interviewed EXIM officials. For more information, contact Nagla'a El-Hodiri at elhodirin@gao.gov.