Whether undocumented immigrants are “illegal” depends on how they ended up without status. Federal law treats overstaying a visa as a civil violation handled in immigration court, while physically crossing the border without inspection is a federal crime prosecuted in criminal court. Most undocumented people in the United States fall into the first category, which is why the blanket label “illegal” describes the politics of the debate more accurately than the legal reality.
Overstaying a Visa Is Civil, Not Criminal
The most common route to being undocumented is entering the country legally on a visa and staying past the authorized date. Federal law makes anyone who violates the terms of their admission, or remains beyond the permitted period, subject to removal.1Office of the Law Revision Counsel. 8 USC 1227 – Deportable Aliens A tourist who arrives on a B-2 visa becomes deportable the day after that visa expires if they are still here.
Removal is a civil matter. It plays out in immigration courts run by the Department of Justice’s Executive Office for Immigration Review, not in the criminal justice system.2Executive Office for Immigration Review. Learn About the Immigration Court There is no arrest for the overstay itself, no criminal record generated by the overstay, and no jail sentence attached to it. You do have the right to a lawyer, but the statute makes clear it will be “at no expense to the Government,” so no attorney is appointed for you the way one would be in a criminal case.3Office of the Law Revision Counsel. 8 USC 1229a – Removal Proceedings
The civil label does not mean the consequences are minor. Anyone unlawfully present for more than 180 days but less than a year is barred from returning for three years after they leave. Cross the one-year mark, and the bar becomes ten years.4Office of the Law Revision Counsel. 8 USC 1182 – Inadmissible Aliens Those bars apply whether the person leaves voluntarily or is removed, which is why many long-time overstayers do not depart on their own: doing so triggers a decade-long ban on coming back through legal channels.
Crossing the Border Without Inspection Is a Federal Crime
Entering the country at any place other than an official port of entry, avoiding inspection by immigration officers, or gaining admission by lying to them is a federal criminal offense under 8 U.S.C. § 1325.5Office of the Law Revision Counsel. 8 USC 1325 – Improper Entry by Alien6Office of the Law Revision Counsel. 18 USC Part II, Chapter 227, Subchapter C – Fines A second or subsequent offense is a felony carrying up to two years.
An important detail gets lost in most public discussion: the statute criminalizes the act of entering, not the state of being present afterward. Once someone is inside the country, their ongoing lack of status is a civil issue, even if the initial crossing was a crime. That means the same person can face two separate proceedings—a criminal case in federal district court over how they arrived, and a civil removal case in immigration court over their status now.
Asylum Applicants Are Treated Differently
Federal law allows anyone physically present in the United States to apply for asylum regardless of how they got here, including people who crossed without inspection.7Office of the Law Revision Counsel. 8 USC 1158 – Asylum The application must generally be filed within one year of arrival, with exceptions for changed conditions in the home country and for unaccompanied minors. An asylum claim does not erase the underlying unauthorized entry, but it creates a legal framework to remain in the country while the case is pending, and a grant of asylum leads to lawful status.
Coming Back After Deportation Is Treated More Seriously
The law is much harder on people who return after having been formally removed. Under 8 U.S.C. § 1326, reentering or being found in the country after a prior removal, without the Attorney General’s consent, is a felony punishable by up to two years in prison on its own.8Office of the Law Revision Counsel. 8 USC 1326 – Reentry of Removed Aliens
The maximum sentence climbs based on what led to the earlier removal:
- Up to 10 years if the person was removed after three or more misdemeanor convictions involving drugs or violence, or after any non-aggravated felony.8Office of the Law Revision Counsel. 8 USC 1326 – Reentry of Removed Aliens
- Up to 20 years if the removal followed an aggravated felony conviction.8Office of the Law Revision Counsel. 8 USC 1326 – Reentry of Removed Aliens
Fingerprint records are how agents identify people with prior removal orders, and illegal reentry is one of the most heavily prosecuted federal crimes on the southern border. On the civil side, someone caught after a prior deportation does not get a new hearing. The old removal order is reinstated, and the government has a 90-day window to carry out the deportation, during which the person is detained.9Office of the Law Revision Counsel. 8 USC 1231 – Detention and Removal of Aliens Ordered Removed
Constitutional Protections Still Apply
Whatever route brought someone here, the Constitution does not stop at citizenship. In Zadvydas v. Davis, the Supreme Court reaffirmed that the Due Process Clause “applies to all persons within the United States, including aliens, whether their presence is lawful, unlawful, temporary, or permanent.”10Justia. Zadvydas v. Davis, 533 US 678 (2001) In Plyler v. Doe, the Court struck down a Texas statute that barred undocumented children from public schools, holding that the Fourteenth Amendment’s protections “are universal in their application, to all persons within the territorial jurisdiction, without regard to any differences of race, of color, or of nationality.”11Library of Congress. Plyler v. Doe, 457 US 202 (1982)
These protections are procedural. They mean officers still need probable cause, warrants still apply to home searches in most situations, and people still get a hearing. They do not shield anyone from removal itself.
The Word “Illegal” Is a Political Choice, Not a Legal One
The federal code uses one term: “alien,” defined as any person who is not a citizen or national of the United States.12Office of the Law Revision Counsel. 8 USC 1101 – Definitions The statutes do not classify a person as “illegal.” They classify conduct—an overstay, an unlawful entry, a reentry after removal—and assign consequences to that conduct.
Executive branch language has moved back and forth. The Biden administration pushed “noncitizen” in agency writing. The Trump administration reversed that in January 2025 and returned to “illegal alien” in executive orders and agency documents.13The White House. Protecting the American People Against Invasion Congress did not change the statutory text through either shift. News organizations and advocacy groups mostly use “undocumented” or “unauthorized”; legal filings stick with “alien” because that is what the statutes say.
So the direct answer: a person who overstayed a visa broke a civil rule and is deportable, not a criminal. A person who crossed without inspection committed a federal misdemeanor at the moment of entry, and their continued presence afterward is a civil matter. A person who came back after being deported is committing an ongoing felony. Calling all of them “illegal” collapses three different legal situations into one word, and the word does not appear anywhere in the statute that governs them.