The Basics of the Immigration Legal System

Disclaimer: This article is for general informational purposes only and is not legal advice.

The U.S. immigration system is large and complex. It is also split between different parts of the broader federal government.

At the highest level, immigration functions fall under two branches of government:

1. The executive branch, which processes and enforces immigration law.

2. The judicial branch, which includes the immigration courts

The immigration agencies which are responsible for processing or enforcing immigration law belong to the Department of Homeland Security (DHS). The courts, however, belongs to the Department of Justice (DOJ). Understanding this structure will hopefully help in understanding how a person moves through the system.

Department of Homeland Security (DHS)

DHS is the primary federal department responsible for carrying out and enforcing immigration laws. Inside DHS are three separate agencies, each responsible for a different part of the process.

U.S. Citizenship and Immigration Services (USCIS)

USCIS is the benefits and applications agency. It handles almost all immigration forms people file to gain a benefit or status, such as:

• Green cards

• Citizenship

• Work permits

• Affirmative asylum

• DACA

• Family petitions

• Humanitarian programs

USCIS officers do not arrest or detain people; their role is adjudicating applications.

Immigration and Customs Enforcement (ICE)

ICE is the interior enforcement agency. They:

• Locate and detain individuals who may be in violation of immigration law

• Operate immigration detention centers

• Carry out deportations

• Provide prosecutors (OPLA) who represent the government in immigration court

If someone is placed in removal proceedings, ICE is the agency that prosecutes the case.

Customs and Border Protection (CBP)

CBP is responsible for the border and ports of entry, including airports, land crossings, and seaports. Their role includes:

• Screening people and goods entering the United States

• Enforcing immigration laws at the border

• Conducting initial processing of many migrants and asylum seekers

In summary:

• USCIS = benefits

• ICE = enforcement

• CBP = border

While all three are part of DHS, each operates independently.

Department of Justice 

Executive Office for Immigration Review (EOIR) 

EOIR is not part of DHS. It belongs to the U.S. Department of Justice (DOJ). EOIR operates the immigration courts and includes:

• Immigration Courts, where immigration judges conduct removal (deportation) cases

• The Board of Immigration Appeals (BIA), which reviews decisions issued by immigration judges

ICE attorneys prosecute cases before immigration judges, but DHS agencies (USCIS, ICE, CBP) cannot direct judges on how to rule. EOIR is separate from DHS in both structure and function.

How These Agencies Interconnect

A simplified overview of how a person may move through the system looks like this:

1. A person comes into contact with immigration authorities

• At the border: CBP processes them

• Inside the U.S.: ICE may arrest them or issue a Notice to Appear

2. If removal proceedings are started, the case goes to EOIR

• ICE attorneys prosecute

• The immigrant, or Respondent, can present defenses, such as protection under the Convention Against Torture, defensive asylum, Cancellation of Removal, or Voluntary Departure

• An immigration judge decides whether the person must leave or may remain

3. If the person applies for an immigration benefit, the application usually goes to USCIS

• Examples: green card, citizenship, work permit, affirmative asylum

• USCIS decisions can affect what happens in court

4. If a person is ordered removed, ICE carries out the removal

Essentially, CBP controls the front door, USCIS handles immigration benefits, ICE enforces immigration laws inside the country. EOIR decides removal cases and reviews appeals, DHS houses USCIS, ICE, and CBP, and the DOJ houses EOIR.

The information in this article is provided for general educational purposes only and does not constitute legal advice. Reading this publication does not create an attorney-client relationship between you and Zia Pathways Law or the attorney. Immigration cases are highly factual, and the law changes frequently. We recommend that you consult directly with a qualified immigration attorney for advice appropriate to your situation.

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