U.S. Immigration and Customs Enforcement recorded about 43,000 arrests in June, 49,000 in July and nearly 51,000 in August—the highest monthly total since Trump returned to office. ICE does not distinguish in its arrest figures between cases initiated by local officers and those initiated by federal authorities, making it difficult to measure the partnerships’ precise role.

The agreements, known as 287(g), authorize participating local or state law enforcement officers to carry out certain federal immigration duties. The number of participating agencies climbed from 135 before Trump took office in January 2025 to 2,608 as of Oct. 1, according to Department of Homeland Security data. Agencies in 38 states have agreements, with the largest numbers in Texas and Florida, where state laws require local participation.

Maryland is one of 12 states without an agreement. State lawmakers passed a law restricting local police cooperation with federal immigration agencies, with supporters arguing that separating local policing from immigration enforcement can help preserve residents’ trust in police.

Congressional Republicans have approved billions in federal support for the partnerships. Trump’s 2025 domestic policy law set aside about $4 billion for state and local immigration enforcement, including 287(g) programs. A separate measure passed in June, the Secure America Act, allocated more than $31 billion to implement the agreements, according to the figures reported by the Department of Homeland Security and congressional records.

Theresa Cardinal Brown, a former senior Homeland Security official under Presidents George W. Bush and Barack Obama, said federal reimbursements have changed the program’s appeal to local governments. Previously, she said, participating agencies generally had to cover training costs themselves. Federal money now makes joining “a budget plus-up” for some jurisdictions.

Ariel G. Ruiz Soto, a senior policy analyst at the Migration Policy Institute, said the expansion of agreements in Texas, Florida and elsewhere likely contributed to the summer increase in arrests. A University of California-backed project analyzing enforcement data attributed at least 6,150 July arrests—about 12.5% of that month’s total—to the program.

The partnerships have three models. Under the jail enforcement model, trained local officers can check the immigration status of people arrested on local charges and hold them for ICE for up to 48 hours. The warrants service model allows officers to serve administrative immigration warrants issued by ICE officials, rather than judges. The task force model gives deputized local officers broader authority to ask about immigration status, detain people and transfer them to ICE.

More than 71% of current agreements use the task force model, according to Titus Consulting, which tracks the program. The second Trump administration revived that model after the Obama administration discontinued it in 2012 amid concerns about racial profiling.

Todd Bensman, a senior research fellow at the conservative Heritage Foundation’s Border Security and Immigration Center, called the task force approach the most effective for making arrests, saying it allows local officers to arrest people and contact ICE for pickup.

The 287(g) program was created by a 1996 law but gained prominence after the Sept. 11, 2001, attacks. It first received federal appropriations in 2006. Earlier efforts to link local policing and immigration enforcement also drew objections from advocates who warned that immigrants might avoid reporting crimes for fear of being detained.

The Trump administration has threatened to withhold federal funding from jurisdictions that do not assist with immigration enforcement, while offering new funding to those that participate. Ruiz Soto said Congress has provided money for the program for the next three years, leaving a future administration or Congress to decide whether to continue expanding it.