DOD's border mission cost $2.64B; only 12% reimbursed
Summary
The Department of Defense obligated $2.64 billion for southern border operations from the start of fiscal year 2025 through March 31, 2026, funded by realigning $1.74 billion from other FY2025 appropriations, transferring $608 million from its Drug Interdiction account, tapping $300 million in military construction funds, and drawing $472 million so far from a $1 billion pot in the 2025 reconciliation law. Of that $2.64 billion, DOD says only $305 million -- about 12% -- is eligible for reimbursement by the Department of Homeland Security, the agency the operations ultimately support. Two-thirds of the money (66%) came from operation and maintenance accounts not appropriated specifically for border duty, plus another 18% from military personnel funds. One line item shows the cost of a change in plans: DOD budgeted to detain up to 30,000 noncitizens at Guantanamo Bay, found it cost-prohibitive to meet ICE detention standards, downsized the operation by mid-February 2025 -- and still spent $66 million on it.
Five ways to pay for a mission with no budget of its own
realigned $1.74 billion⧉ from various FY2025 appropriation categories, transferred $608 million from or through its Drug Interdiction and Counter-Drug Activities account, and tapped $300 million in existing military construction funds for border barrier projects. It has since begun drawing on a $1 billion pot from the 2025 reconciliation law -- the One Big Beautiful Bill Act -- obligating $472 million of it as of March 31, 2026. And starting in fiscal year 2026, began providing some support to that actually qualifies for reimbursement, rather than absorbing the cost itself.
Where the money actually went
Border security -- ground and air operations like detection, monitoring, and aviation support -- accounted for $1.45 billion⧉, 55% of the total. Managing the five (soon six) "National Defense Areas" -- militarized zones of federal border land now under installation control -- cost $387 million. Building and running immigration detention facilities in the continental U.S. cost $366 million, before transferred that operation to and dropped the category entirely in fiscal year 2026. Permanent border barrier construction, including a 30-foot steel bollard wall project in Arizona, cost $275 million.
View data as table
| Border security | 1,450 |
|---|---|
| National Defense Areas | 387 |
| Continental U.S. detention | 366 |
| Permanent border barrier | 275 |
| Territorial integrity | 73 |
| Operation Southern Guard | 66 |
| Information environment ops | 25 |
Paid for out of accounts built for something else
Break the same $2.64 billion down by what kind of money it came from⧉, rather than what it paid for, and the picture is starker: 66% came from operation and maintenance accounts, and another 18% from military personnel funds -- neither appropriated with border operations specifically in mind. Only $305 million of the full $2.64 billion qualifies for reimbursement from . is absorbing the remaining roughly $2.3 billion itself.
View data as table
| Operation and maintenance | 1,750 |
|---|---|
| Military personnel | 487 |
The Guantanamo Bay operation that shrank but still cost $66 million
One line item shows what a reversed plan costs. 's Operation Southern Guard was built to support DHS-led immigration detention at Naval Station Guantanamo Bay⧉ for as many as 30,000 noncitizens. Officials deemed that infeasible -- building facilities that met detention standards was cost-prohibitive -- and downsized the mission by mid-February 2025, just weeks after standing up a joint task force headquarters there. The operation still cost $66 million, mostly spent moving personnel and equipment before the scale-back.
The takeaway
- is paying for a mission it has no dedicated budget for. $2.64 billion obligated through five separate funding maneuvers -- realignments, transfers, construction-fund reprogramming, a reconciliation-law appropriation, and limited reimbursable support.
- is reimbursing only a sliver of it. Just $305 million, about 12%, qualifies for reimbursement -- is absorbing roughly $2.3 billion of the total itself, funded 84% out of operation-and-maintenance and military-personnel accounts not earmarked for the border.
- A scaled-back plan still cost tens of millions. budgeted to detain 30,000 people at Guantanamo Bay, found it cost-prohibitive, downsized within weeks -- and the operation still ran $66 million.
All findings are from -26-108437, "Southern Border Security: Used Multiple Strategies to Fund Operations," a report to congressional committees published and publicly released July 13, 2026 -- read directly in full (35 pages), not just the Highlights summary. Cost figures reflect 's own reporting through its Advana enterprise system as of March 31, 2026 (military personnel figures for Army, Navy, and Air Force as of the end of February 2026); did not independently audit whether all reported costs were fully and accurately captured. This report did not include formal recommendations to .
Sources(1) ▾
- U.S. Government Accountability Office, Southern Border Security: DOD Used Multiple Strategies to Fund Operations (2026-07-13) — -26-108437, a report to congressional committees requested by a provision in the National Defense Authorization Act for Fiscal Year 2026, published and publicly released July 13, 2026. Read the full 35-page PDF directly (extracted with pdftotext -layout) -- the seven-category cost breakdown, the appropriation-category breakdown, and the Operation Southern Guard detail are only in the full report, not the Highlights summary. Direct gao.gov PDF asset access intermittently returns HTTP 403 and the Wayback save/lookup endpoints failed at capture time (HTTP 520 / no snapshot); the Artemis-sealed copy of the product page serves as the one-click capture. gao.gov · original document
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The Department of Defense obligated $2.64 billion⧉ for southern border operations from the start of fiscal year 2025 through March 31, 2026, according to a report published July 13, 2026. has no dedicated budget line for this mission -- it pieced the money together from five different sources. Only $305 million of it⧉ -- about 12% -- is eligible for reimbursement by , the agency the operations ultimately support.