Glossary of terms

Words that show up in papers, phone calls, and conversations with an attorney. Just definitions — what a term means, not what to do about it.

Updated July 28, 2026

This is a dictionary, not legal advice

The definitions below are general and do not account for a specific case. Some rules differ by state and appellate circuit, and the wording in the law is more precise than this short summary. How a term applies to a particular case is something an attorney determines.

Who is who

ICE: Immigration and Customs Enforcement. An agency of the Department of Homeland Security (DHS) that locates, detains, and removes people without legal status inside the country.
ERO: Enforcement and Removal Operations — the part of ICE that carries out arrests, holds people in custody, and organizes removals.
CBP: Customs and Border Protection. Operates at the border, ports, and airports; a separate agency from ICE.
USCIS: U.S. Citizenship and Immigration Services. Processes applications for status — green cards, citizenship, work permits. Does not carry out detentions.
DHS: Department of Homeland Security. The parent agency over ICE, CBP, and USCIS.
EOIR: Executive Office for Immigration Review. Part of the Department of Justice, separate from DHS. Hears removal cases.
Immigration Judge (IJ): A judge of an EOIR immigration court, appointed by the Department of Justice — not the same thing as a federal judge.
BIA: Board of Immigration Appeals. Hears appeals of an immigration judge’s decisions.
Deportation officer, Officer of Record: The ICE ERO officer assigned to a specific detained person’s case.
Field office: A regional ICE ERO office covering a given area. See the office finder page.

Detention and status

A-Number, A-file: A nine-digit number assigned to a person in the immigration system, and the file of documents kept under it. The key to searching ICE and EOIR records.
Detainer (ICE hold): A request from ICE to a local jail or police department to hold a person for a further period — usually up to 48 hours — past the time they would otherwise be released, so ICE can take custody.
Mandatory detention: Custody with no separate hearing on the possibility of bond, when it applies to a case — for example, under certain criminal grounds (INA § 236(c)).
Bond: A monetary payment that secures a person’s release from ICE custody while a case is pending.
Bond hearing: A separate hearing before an immigration judge about the amount of bond, or whether one is set at all.
ATD: Alternatives to Detention — forms of supervision outside a detention facility: an ankle monitor, a check-in app, or scheduled appearances.
ISAP: Intensive Supervision Appearance Program — a private ATD program run under contract with ICE by BI Incorporated.
Check-in: The requirement to periodically report to an ICE office, or check in by phone or app, as part of ATD or after release.
Credible fear interview: An interview with a USCIS officer for a person stopped at the border or re-entering the country, about whether they have a credible fear of persecution at home.
Reasonable fear interview: A similar interview for a person with a prior removal order or certain convictions. The bar to pass it is higher than for credible fear.

The court process

Removal proceedings: The EOIR court process deciding whether a person must leave the United States.
NTA, Notice to Appear (Form I-862): The document that starts removal proceedings: it lists allegations about the person and the charges.
Master calendar hearing: A short administrative hearing: the judge checks the status of the case, sets the next date, and notes whether the person has an attorney.
Individual hearing (merits hearing): The main hearing on the merits of the case, where evidence is presented and a decision is made.
Continuance: Postponing a hearing to a later date.
In absentia order: A removal order issued when a person did not appear for a scheduled hearing.
Venue: The EOIR court where a specific case is heard. It can change when a person is transferred between detention facilities.
Docket number: The number under which a case is registered with the court.

Relief and outcomes

Asylum: A form of protection for a person who cannot return home due to persecution based on race, religion, nationality, political opinion, or membership in a particular social group.
Withholding of removal: A narrower protection than asylum: it bars removal to a specific country but does not lead to a green card.
CAT protection: Protection under the Convention Against Torture — from removal to a country where the person would face torture by, or with the consent of, the government.
Cancellation of removal: Cancels a removal order when certain conditions are met. The rules differ for lawful permanent residents (LPRs) and for others.
Voluntary departure: Permission to leave the U.S. on one’s own and at one’s own expense instead of a forced removal. It can differ from a removal order in its effect on future entry.
Prosecutorial discretion: A decision by ICE or an EOIR prosecutor not to pursue a case further, or to close it, based on agency priorities.
Adjustment of status: Changing status to permanent residence (a green card) without leaving the United States.
Order of removal: The court’s final decision that a person must be removed.
Stay of removal: A temporary postponement of carrying out a removal order.
Motion to reopen, motion to reconsider: A request to have a case reviewed again based on new facts or an error in the decision.
Appeal to the BIA: Challenging an immigration judge’s decision before the Board of Immigration Appeals.
Habeas corpus: A separate case filed in federal district court — not EOIR — about the lawfulness of the detention itself, under 28 U.S.C. § 2241. Prepared and filed by an attorney.

Status and documents

LPR, green card: Lawful Permanent Resident — the status of a permanent U.S. resident.
EAD: Employment Authorization Document — a work permit, separate from a green card.
TPS: Temporary Protected Status — a temporary status for nationals of certain countries it is unsafe to return to (natural disaster, armed conflict).
Naturalization: The process of becoming a U.S. citizen.
Sponsor, petitioner: The person or organization filing a petition on behalf of a relative or worker so they can obtain status.

Information updated July 28, 2026. Rules change — check the date.

We are not attorneys and we do not give legal advice. This page has facts and links to official sources only.