How Many Prisoners in Guantanamo Bay: Costs and Cleared Detainees

As of early 2026, fifteen prisoners remain at the Guantánamo Bay detention facility, down from a peak of roughly 780 men and boys held there since the prison opened in January 2002.¹ The number has dropped steadily across four administrations through transfers, repatriations, plea deals, and nine deaths in custody, but the remaining fifteen include men who have been held for more than two decades without charge, men cleared for release who are still there, and defendants in military commission cases that have not reached trial after fourteen years of pretrial proceedings.

Who the 15 Detainees Are

The remaining prisoners fall into four groups based on their legal status.¹

Seven charged, awaiting trial. Five are the co-defendants in the September 11 case: Khalid Shaikh Mohammed and four others accused of planning the 2001 attacks. One is Abd al-Rahim al-Nashiri, facing capital charges for the October 2000 bombing of the USS Cole, which killed 17 American sailors. The seventh is Encep Nurjaman, an Indonesian national known as Hambali.²

Two convicted. Ali Hamza Ahmad Suliman al-Bahlul, a Yemeni national, is serving a life sentence from a 2008 military commission conviction. Abd al-Hadi al-Iraqi, an Iraqi national, was sentenced to ten years in June 2024 under a 2022 plea deal.²

Three cleared for transfer but still held. Muieen Abd al-Sattar, a stateless Rohingya man, was cleared for release as far back as 2010. Gouled Hassan Duran, a Somali national, was approved in November 2021. Ismael Ali Bakush, a Libyan national, was approved in September 2022. All three remain at the facility pending security arrangements with a receiving country.²

Three held indefinitely without charge. Abu Zubaydah (Zayn al-Abidin Muhammad Husayn), a Palestinian captured in Pakistan in March 2002 and the first “high-value detainee” subjected to CIA “enhanced interrogation techniques,” has been held for more than twenty years without ever being charged. Abu Faraj al-Libi, a Libyan national, and Muhammad Rahim, an Afghan national, are in the same category.¹³

How the Count Fell From 780 to 15

Roughly 780 people have been held at Guantánamo since the facility opened.⁴¹⁵

Most of the reduction happened early. President George W. Bush transferred out roughly 540 detainees, with the largest groups going to Afghanistan (198), Saudi Arabia (121), and Pakistan (50).¹⁶ President Obama inherited 242 detainees and transferred about 200 during his two terms, resettling detainees in more than 30 countries.⁷ During Trump’s first term, only one detainee was transferred, to a prison in Saudi Arabia.⁸ Under President Biden, 13 detainees were repatriated, 11 were transferred to Oman, and one was freed.

Recidivism figures have followed each wave of transfers. Human Rights First reported that about 36 percent of detainees released under the Bush administration were confirmed or suspected of returning to militant activity, compared with roughly 13 percent of those released under Obama’s more rigorous interagency review.⁹

Why Cleared Detainees Are Still Held

Three of the fifteen have been approved for transfer through the Periodic Review Board, an interagency panel established by Executive Order 13567 in 2011 that decides whether continued detention is necessary to protect against a significant threat to U.S. security.¹⁰ Approval by the PRB does not free anyone. A receiving country must agree to take the person, security arrangements must be negotiated, and Congress must permit the transfer.

Congressional restrictions embedded in annual defense spending bills prohibit transferring any Guantánamo detainee to U.S. soil, including for medical treatment, and the National Defense Authorization Act contains provisions restricting the use of government funds for transfers to third countries.¹¹¹² The board itself has also stalled at times. Before January 2017, it approved 38 detainees for transfer. Under the first Trump administration, no additional transfers were approved, and a 2018 analysis found that multiple PRB decisions went unpublished for hundreds of days, leaving detainees in procedural limbo.¹³

Every president since Bush has confronted whether to close the prison. Obama signed a closure order on his second full day in office and submitted a plan in February 2016 to move remaining detainees to domestic prisons; Congress rejected it.¹⁴¹⁵ Trump signed an executive order in January 2018 to keep the prison open. Biden expressed a desire to close it but left office without doing so.

What Fifteen Prisoners Cost

Guantánamo is by a large margin the most expensive detention facility the United States operates. As of 2019, the total annual cost of holding prisoners, running the war court, and supporting related construction exceeded $540 million — roughly $13 million per detainee per year.¹⁶ Congressional testimony in 2016 put the annual cost of holding a prisoner in a federal supermax at about $78,000.¹⁷ Senate reporting places the per-detainee cost at approximately $13 million per year.¹⁸

The Immigration Detainees Are a Separate Population

The fifteen war-on-terror prisoners are not the only people the base has held recently, and the two groups are sometimes conflated. In January 2025, President Trump issued a memorandum directing the expansion of the Migrant Operations Center at the naval base to “full capacity” to hold noncitizens for immigration enforcement, with an announced goal of housing up to 30,000 migrants.¹⁹²⁰

The actual numbers have been much smaller. About 500 migrants were held at the base for short periods beginning in February 2025. A federal class action filed in June 2025 alleged that roughly 70 immigrant detainees were being held under what plaintiffs described as “punitive” conditions.²⁰ By May 2026, Secretary of Defense Pete Hegseth reported that 832 people had been detained at the facility under the current administration for immigration purposes, with projected support costs of approximately $73 million and a current maximum capacity for immigration detainees of 50.²¹ An effort in February 2025 to build 195 tents for about 2,000 noncitizens at a cost of over $3 million was paused after the administration concluded the tents did not meet detention standards.¹⁸

The immigration detainees are held under separate legal authority, in a separate part of the base, from the fifteen prisoners held under the 2001 Authorization for Use of Military Force.

An Aging Population

The fifteen who remain have grown old at the facility. By 2019, the oldest detainee was 71, several others were in their fifties, and some had begun using canes and walkers, with conditions including spinal degeneration, sleep apnea, depression, and early signs of cognitive impairment.¹²

The International Committee of the Red Cross reported in 2023 that detainees were experiencing “accelerated ageing” from the cumulative effects of long-term detention and their personal histories, and called on the United States to adapt its medical infrastructure if it intended to continue holding them. The ICRC also noted a “total absence of in-person visits” from families.²² A joint report by Physicians for Human Rights and the Center for Victims of Torture documented systemic failures in medical care, including the subordination of medical decisions to security concerns, rapid staff rotation, and the absence of documented trauma histories in medical records at a facility where many detainees were subjected to CIA interrogation before arriving.²³ Congress has prohibited transferring detainees to the U.S. mainland for medical treatment, and medical staff are restricted from asking detainees about injuries that may have resulted from past interrogation.¹²

For the fifteen prisoners who remain, the practical questions are no longer only about charges, trials, and transfers. They are also about who will care for an aging group of men at a facility that was not built for that purpose, and for how long.

1
The New York Times. Guantánamo Bay Detainees
2
Close Guantánamo. Prisoners
3
United Nations. UN Experts Call for Release of Guantánamo Bay Detainee Abu Zubaydah
4
Center for Constitutional Rights. Guantánamo by the Numbers
5
Amnesty International. Guantánamo Detainee Deaths Report
6
U.S. Congress. Hearing on Guantanamo Detainee Transfers
7
U.S. Department of State. Remarks on Guantanamo Transfers to Serbia
8
Human Rights First. Guantánamo by the Numbers
9
Human Rights First. Facts About the Transfer of Guantánamo Detainees
10
Periodic Review Secretariat. About the PRB
11
Brooklyn Law School. Guantánamo Detention and International Law
12
Defense One. Guantánamo as Nursing Home for Terrorist Suspects
13
Lawfare. Who Broke Periodic Review at Guantánamo Bay
14
Britannica. Guantánamo Bay Detention Camp
15
Al Jazeera. Timeline: 20 Years of Guantánamo Bay Prison
16
The New York Times. Guantánamo Bay Cost
17
U.S. Congress. Hearing on Guantanamo Closure Plan
18
U.S. Senate HSGAC. GTMO Report
19
The White House. Expanding Migrant Operations Center at Naval Station Guantanamo Bay to Full Capacity
20
Politico. Trump Guantánamo Bay Transfers Pause
21
U.S. House of Representatives. Hegseth Reveals Cost of Detaining Immigrants at Guantanamo Bay
22
ICRC. Guantánamo: Detaining Authorities Must Adapt to Needs of Rapidly Ageing Population
23
Physicians for Human Rights. Report Documents Pervasive Deficiencies in Medical Care at Guantánamo