U.S. Immigration & Customs Enforcement — Interior Immigration Enforcement

U.S. Immigration and Customs Enforcement is the DHS component responsible for enforcing immigration law in the interior of the United States and investigating transnational crimes — a dual mission that combines what were previously the enforcement functions of the Immigration and Naturalization Service (INS, abolished in 2003) and the investigative functions of the U.S. Customs Service. With approximately 20,000 employees and an annual budget exceeding $9 billion, ICE is organized into two principal operational components: Enforcement and Removal Operations (ERO), which arrests, detains, and deports noncitizens, and Homeland Security Investigations (HSI), which investigates financial crimes, human trafficking, drug smuggling, cybercrimes, and other transnational threats. ICE's interior enforcement authority — reaching noncitizens anywhere in the United States, not just at the border — makes it the operational agency through which successive administrations have pursued dramatically different immigration enforcement priorities, from the Obama administration's "felons, not families" prioritization to the Trump administration's mass deportation operations targeting all removable noncitizens regardless of criminal history.

Legal Authority

• 8 U.S.C. § 1226 — Immigration and Nationality Act § 236; authorizes arrest and detention of aliens pending removal proceedings; permits civil immigration detention without criminal charges; the primary authority for ICE's detention operations
• 8 U.S.C. § 1227 — INA § 237; establishes the grounds for removal (deportability) of aliens who have been admitted; covers criminal convictions, visa violations, and other post-entry conduct
• 8 U.S.C. § 1229a — INA § 240; establishes removal proceedings before immigration judges; defines the adjudicatory process in which ICE (as the government party) presents evidence supporting removal
• 8 U.S.C. § 1231 — INA § 241; requires the government to remove aliens whose removal has been ordered within 90 days; authorizes continued detention beyond 90 days in certain circumstances; establishes the post-order detention framework
• 6 U.S.C. § 251 — Homeland Security Act of 2002; transfers immigration enforcement functions from INS to DHS; ICE is created within DHS with interior enforcement responsibilities

Key Mechanics

ICE exercises civil immigration enforcement authority through two primary divisions. Homeland Security Investigations (HSI) is a federal law enforcement agency within ICE that investigates transnational crime — human trafficking, drug smuggling, money laundering, child exploitation, weapons trafficking, and cybercrime — through criminal investigations, often partnering with other federal agencies. Enforcement and Removal Operations (ERO) is the civil immigration enforcement arm: it arrests and detains removable aliens, manages the immigration detention system (approximately 35,000–40,000 daily detainees, held in government-owned and contracted facilities), and physically removes ordered individuals from the United States (approximately 100,000–200,000 removals per year depending on administration priorities). ERO agents carry civil immigration arrest authority under INA § 236 — not criminal arrest authority. Interior civil arrests may occur in the community ("at-large arrests"), at courthouses, or through 287(g) agreements with local law enforcement agencies. ICE cannot enter a private home without consent or a judicial warrant; it may conduct civil immigration arrests in public places. Detainees in removal proceedings have a right to a hearing before an immigration judge and appeal to the Board of Immigration Appeals, but do not have a Sixth Amendment right to appointed counsel.

Organization & Structure

ICE was created when the Homeland Security Act of 2002 abolished the INS and split its functions: CBP received border enforcement and port-of-entry operations; USCIS received benefits adjudication; and ICE received interior enforcement. The ICE Director is appointed by and serves at the pleasure of the DHS Secretary, without Senate confirmation. ICE operates 24 field offices covering the entire United States, with additional attaches in foreign countries working with international counterparts on transnational crime investigations.

Key Functions & Authorities

Enforcement and Removal Operations (ERO) — ERO is responsible for identifying, arresting, detaining, and removing noncitizens who are unlawfully present in the United States or who are deportable under the INA. ERO's arrest authority stems from 8 U.S.C. § 1226 (detention of noncitizens pending removal proceedings) and § 1227 (grounds of deportability). Removal proceedings before the Executive Office for Immigration Review (EOIR, a DOJ component) determine whether a noncitizen is removable; ERO then executes the removal order. ICE maintains a nationwide detention network — contracted facilities, ICE-owned facilities, and intergovernmental service agreements with county jails — holding approximately 37,000-41,000 detainees on any given day. Administrative removal (bypassing immigration courts for certain categories) and reinstatement of final orders of removal are faster tracks that ERO uses extensively.

287(g) partnerships — Section 287(g) of the INA authorizes DHS to enter agreements with state and local law enforcement agencies (LEAs) that allow trained local officers to perform immigration enforcement functions — including identifying and detaining deportable noncitizens encountered during routine law enforcement activities. Approximately 150 LEAs have active 287(g) agreements; these arrangements are controversial in jurisdictions that have adopted sanctuary policies limiting such cooperation.

Detainers — ICE issues immigration detainers (Form I-247) to law enforcement agencies that have a noncitizen in custody, requesting that the agency hold the individual for up to 48 hours after the state/local authority would otherwise release them, to allow ICE to assume custody. Sanctuary jurisdictions — cities and counties that have formally declined to honor detainers — have been a persistent source of federal-state tension, particularly regarding federal grant conditions and withholding of Byrne JAG funds.

Homeland Security Investigations (HSI) — HSI is one of the largest investigative agencies in the federal government, with approximately 10,000 special agents and support personnel investigating transnational crime: human trafficking and smuggling, drug trafficking, financial crimes (bulk cash smuggling, trade-based money laundering), intellectual property theft, child exploitation (Project Vic/Operation Rescue operations), cybercrimes, and export control violations. HSI operates 70 domestic offices and 80 attache offices in 53 countries. Unlike ERO, HSI investigations frequently do not involve immigration status and have generated proposals to separate HSI from ICE into an independent investigative agency.

Expedited removal — The INA authorizes expedited removal (8 U.S.C. § 1225(b)) of arriving noncitizens and others who are inadmissible. The geographic scope of expedited removal has been administratively expanded and contracted: the Obama administration limited it primarily to recent border crossers; the first Trump administration expanded it to cover noncitizens in the entire country who could not demonstrate 2 years of continuous presence; the Biden administration narrowed it again; the second Trump administration re-expanded it in 2025. The Supreme Court has affirmed limited judicial review of expedited removal determinations.

How It Affects You

If you are a citizen or voter: ICE enforcement operations in communities with large immigrant populations generate significant local controversy — workplace raids, neighborhood enforcement operations, and school/church enforcement near sensitive locations have been recurring political issues. ICE's record of deportations by year, nationality, and criminal history is publicly reported (though often disputed); the agency's annual "enforcement and removal operations" report is the primary transparency mechanism. HSI investigations address crimes — human trafficking, child exploitation, financial fraud — that directly affect public safety.

If you are a business or regulated entity: ICE Form I-9 audits — reviewing employer documentation of employment authorization — are a significant compliance risk for industries with large immigrant workforces. ICE audits can result in civil fines (paperwork violations $288-$2,861 per Form I-9; knowing-hire violations from $716-$5,724 per worker for a first offense up to $28,619 per worker for third/subsequent offenses, per the 2026 DOJ inflation adjustment) and criminal prosecution for knowing employment of unauthorized workers. HSI's export control investigations (working with the Commerce Department's BIS) affect defense contractors, technology companies, and businesses with foreign operations.

If you work at a federal agency: ICE coordinates with DOJ's EOIR (which runs immigration courts), the State Department (deportation flights require receiving country cooperation; foreign policy considerations affect removal operations), the U.S. Marshals Service (detention and transportation), and CBP (handoffs of border apprehensions). DOJ Civil Rights Division monitors ICE detention conditions. Congressional appropriations and directives set detention bed levels and funding for enforcement operations.

If you are a journalist, researcher, or policy analyst: ICE publishes annual Enforcement and Removal Operations (ERO) reports with detailed data on arrests, detentions, and removals by nationality, criminal history, and program type. The Transactional Records Access Clearinghouse (TRAC) at Syracuse University aggregates ICE enforcement data obtained through FOIA, providing the most comprehensive independent analysis of enforcement trends. ICE detention facility inspection reports (by OIG and the DHS Office for Civil Rights and Civil Liberties) are publicly available. The ACLU, Human Rights Watch, and the National Immigration Law Center track ICE enforcement practices and litigation.

Recent Developments

• 2025 — The Trump administration launched large-scale interior enforcement operations targeting all removable noncitizens (not limited to those with criminal records), including raids in sanctuary cities, enforcement near schools and churches, invocation of the Alien Enemies Act of 1798 for expedited deportation of alleged gang members to El Salvador's CECOT detention facility, and a stated goal of conducting one million deportations per year — the largest planned deportation operation in U.S. history; federal courts issued emergency stays in multiple circuits challenging AEA invocations and expedited removal expansions.
• 2024 — ICE deportations reached approximately 271,000 — the highest under the Biden administration — after a record-high 2023 border encounter surge prompted policy changes; removals for noncitizens without criminal records remained a smaller share than under the Obama administration.
• 2021 — The Biden administration issued enforcement priorities memoranda limiting ICE enforcement to recent border crossers, noncitizens posing national security threats, and noncitizens with serious criminal convictions — the "felons, not families" framework; Texas and other states successfully challenged these priorities in court (Texas v. Biden), and the Supreme Court ultimately held that states lacked standing to sue over executive enforcement priorities in United States v. Texas (2023).
• 2017 — The first Trump administration issued an executive order dramatically expanding ICE enforcement priorities to include all removable noncitizens, ended the Obama-era "catch-and-release" policy, and conducted Operation Crosscheck — a series of nationwide enforcement operations; ICE arrests of noncitizens without criminal records increased substantially.
• 2003 — ICE was created by the Homeland Security Act of 2002, which abolished the INS and merged its investigative functions (previously Customs) with interior immigration enforcement; the combination of immigration enforcement and transnational crime investigation in a single agency has periodically generated tension between ICE's two principal missions.