What Does ICE Do?

Immigration and Customs Enforcement ("ICE") is in existence to enforce U.S. immigration laws, secure the nation’s borders, and investigate acts of terrorism and transnational crimes. Learn more about how this federal agency came to be, how it works, and what authority it has.

What Is ICE?

ICE is a federal law enforcement agency and a component of the U.S. Department of Homeland Security (DHS). It is distinct from some of the other federal agencies handling immigration matters, such as U.S. Citizenship and Immigration Services (USCIS), which is mostly a service provider, handling applications for immigration benefits); and Customs and Border Protection (CBP), which carries out enforcement actions mostly in the U.S. border regions and at ports of entry.

What Does ICE Stand For?

ICE is primarily responsible for enforcing federal immigration and customs laws in the United States. It was formed in 2003 as part of the U.S. government's response to the September 11, 2001 terrorist attacks in New York City. It represents a combination of interior and investigative agencies that existed before 9/11, namely elements of the U.S. Customs Service and the Immigration and Naturalization Service (INS).

What Does ICE Do?

ICE is responsible for enforcing federal laws, both criminal and civil, that encompass border control, customs, trade, and immigration. After the FBI, it’s the largest investigative agency in the U.S. federal government. Its powers include investigating, apprehending, arresting, detaining, and removing aliens who are within the United States unlawfully or who have committed acts that make them deportable. ICE agents have been given broad investigative authority, and rely on undercover agents, surveillance, confidential informants, and cooperating defendants.

If you hear a news story about an immigration raid on a U.S. company; an arrest of an undocumented immigrant or human rights abuser within the United States; the detention of a criminal immigrant following release from prison; or the denial of a U.S. visa to a terrorist, an ICE operation was likely behind it or involved in it.

ICE raids and mass actions have become more frequent under the second Trump Administration, with multiple allegations that officers are acting in ways that exceed their authority or reflect clear disregard for facts and constitutional rights. ProPublica, for example, issued an article titled We Found That More Than 170 U.S. Citizens Have Been Held by Immigration Agents. They’ve Been Kicked, Dragged and Detained for Days.

Does ICE Deport Foreign Nationals?

ICE arranges for the deportation (removal) of, on average, more than 500 aliens each day through its Enforcement and Removal Operations (discussed more below). Its first priority is normally to arrest and deport convicted criminals, people who pose a threat to national security, fugitives, and people who have recently entered the country illegally. However, the Trump Administration revoked the memos that made these priorities explicit, and operates more on a "catch as catch can" basis.

When an Immigration Judge or Court Must Decide Whether the Foreign National Is Deportable

In many cases, ICE is not the final decision maker regarding whether someone should be deported. They must often refer cases to the Executive Office of Immigration Review (EOIR), less formally known as the immigration court system.

There, the foreign national will have an opportunity to contest the supposed grounds of deportation and present any relevant defenses, such as proving mistaken identity or presenting a claim for asylum, "cancellation of removal," or a green card based on marriage to a U.S. citizen. If and when the immigration judge issues a final order of deportation, and after any and all appeals have been exhausted, ICE will take over again in handling the foreign nationals' actual removal to their country of origin.

When ICE Can Deport Someone Without Them Seeing a Judge

If a foreign national already has an order of deportation from the immigration court on file, ICE can deport them immediately upon arresting or encountering them.

ICE also has something called "expedited removal" powers, allowing it to turn around and send home anyone who has recently crossed the Southern border into the United States without permission. In the past, the policy was to exercise this only within 200 miles of the border. However, the Trump Administration changed this policy in 2025 to extend expedited removal throughout the United States, to anyone who has spent fewer than two years here. (This issue is currently being litigated.)

When ICE Can Overlook an Undocumented Person

In increasingly rare cases, ICE exercises its prosecutorial discretion to overlook undocumented persons who are law abiding and have family ties here, in order to conserve its resources. Although ICE operates a tip line for people to use in reporting suspicious or criminal behavior related to its mission, it would be a mistake to say it will always or immediately get an undocumented alien deported.

How ICE Operates

Other than its administrative functions, ICE has two principal operating components:

Enforcement and Removal Operations (ERO)

ERO is devoted to the enforcement of U.S. civil immigration laws. It is responsible for identifying "removable aliens"—that is, foreign nationals who are subject to deportation—detaining them, and making sure they leave the United States. (An alien is a foreign-born person who has not become a U.S. citizen, even if the person has a visa, green card, or other immigration status in the U.S.)

ERO also has "fugitive operations teams" that find, apprehend, and remove aliens with outstanding orders of deportation who have failed to report to ICE or depart the United States, or who have returned after removal.

ERO sometimes detains people who arrive at the border without proper documentation, including those who fear persecution in their home countries and request political asylum in the United States. Although detention of such aliens is mandatory under U.S. law, ERO's failure to separate asylum seekers from criminal aliens, or to expedite the processing of their cases while still giving them a full chance to be heard, has drawn criticism from human rights observers.

ERO's immigration enforcement officers and agents operate a detention system and oversee the transportation and deportation of undocumented or criminal aliens. ERO is also responsible for a program that identifies removable aliens in jails and prisons within the United States, then typically picks them up for deportation after they've served their sentences. According to the American Immigration Council, the Trump administration is "locking up hundreds of thousands of people— most with no criminal record—in a harsh immigration detention system that makes it near impossible to fight their cases or secure release."

Homeland Security Investigations (HSI)

The HSI office conducts criminal investigations of the illegal movement of people or goods into, out of, or within the United States. HSI agents investigate a broad spectrum of crimes that have to do with trade, travel, immigration, and finance, including human trafficking, drugs, arms, and contraband smuggling, money laundering, cultural property crimes (art and antiquities theft and smuggling), cybercrime, and terrorism.

HSI agents also investigate potential crimes against critical infrastructure industries that are vulnerable to sabotage or attack. In addition, HSI oversees ICE's international affairs operations and intelligence-gathering, operating in close to 60 countries around the world.

How Are ICE Agents Different From Police?

ICE agents are federal agents and their arrest powers come from federal law, whereas local and state police derive their arrest authority from state law.

Federal law gives ICE agents the authority to investigate and arrest people for violations of immigration laws and crimes against the United States. (8 U.S.C. § 1357 (2023).) State laws authorize local police officers to investigate, arrest, and detain persons within their jurisdictions for violations of state and local laws.

Generally speaking, this division of power means federal ICE agents shouldn't do the job of local police officers and local officers shouldn't do the job of ICE agents. However, some states’ laws allow ICE agents limited arrest authority within their jurisdiction, and some local agencies have agreements with ICE to perform limited immigration functions (typically to turn people over to federal immigration authorities). These agreements vary widely from state to state and even local government to local government.

Getting Help and More Information

If you’re being investigated for an immigration violation, you likely want to speak to a criminal defense attorney and an immigration attorney. You can also find more information on immigration laws at Nolo.com.