United States citizenship can be acquired by birthright in two situations: by virtue of the person's birth within United States territory while under the jurisdiction thereof (jus soli), or because at least one of their parents was a U.S. citizen at the time of the person's birth (jus sanguinis). Birthright citizenship contrasts with citizenship acquired in other ways, for example by naturalization. ("The term 'naturalization' means the conferring of nationality of a state upon a person after birth, by any means whatsoever.") (emphasis added).

Birthright citizenship is explicitly guaranteed to anyone born under the legal "jurisdiction" of the U.S. federal government by the Citizenship Clause of the Fourteenth Amendment to the United States Constitution (adopted July 9, 1868), which states:

All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.

This clause was a late addition to the Amendment, made in order to clarify what some of the drafters felt was already the law of the land: that all those born to parents beholden to U.S. law ("even of aliens") were guaranteed citizenship.See and #Sailor's Snug Harbor below Nonetheless, contrary laws in multiple states had culminated in the Dred Scott v. Sandford decision (1857), wherein the Supreme Court universally denied U.S. citizenship to African Americans regardless of the jurisdiction of their birth.

Since the Supreme Court decision United States v. Wong Kim Ark (1898) the Citizenship Clause has generally been understood to guarantee citizenship to all persons born in the United States and "subject to the jurisdiction thereof", which at common law excluded the children of foreign diplomats and occupying foreign forces.

Native Americans living under tribal sovereignty were excluded from birthright citizenship until the Indian Citizenship Act of 1924.

Over time Congress and the courts similarly extended birthright birthright citizenship to all but one of the inhabited unincorporated territories of Puerto Rico, the Marianas (Guam and the Northern Mariana Islands), and the U.S. Virgin Islands. American Samoa has repeatedly declined US citizenship, one of many Samoan policies and traditions to preserve political and cultural independence.See (defining "State") and (defining "United States"), as well as ..

The Immigration and Nationality Technical Corrections Act of 1994 granted birthright citizenship to children born elsewhere in the world if either parent is a U.S. citizen (with certain exceptions); this is known as jus sanguinis ("right of blood").

Political opposition to jus soli birthright citizenship has arisen in the United States over the past several decades, punctuated by the election of Donald Trump—who explicitly opposes jus soli citizenship for children of undocumented immigrants—as President of the United States in 2016 and 2024. Upon taking office in 2025, Trump issued Executive Order 14160, which asserted that the federal government would not recognize jus soli birthright citizenship for the children of persons who are not US citizens or permanent residents. The executive order was challenged in court, and the Supreme Court struck down the order on June 30, 2026 in the case Trump v. Barbara. On August 6, 2026, Trump signed two new executive orders, again seeking to restrict eligibility for birthright citizenship.

Current U.S. law Citizenship in the United States is a matter of federal law, governed by the United States Constitution.

Since the adoption of the Fourteenth Amendment to the United States Constitution on July 9, 1868, the citizenship of persons born in the United States has been controlled by its Citizenship Clause, which states: "All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside."

Statute, by birth within U.S. Under United States Federal law (), a person is a United States national and citizen if:

the person is born in the United States, and subject to the jurisdiction thereof the person is born in the United States to a member of an Indian, Inuit, Aleutian, or other aboriginal tribe (see Indian Citizenship Act of 1924) the person is of unknown parentage found in the United States while under the age of five years, until shown, prior to his attaining the age of 21 years, not to have been born in the United States the person is born in an outlying possession of the United States of parents one of whom is a citizen of the United States who has been physically present in the United States or one of its outlying possessions for a continuous period of one year at any time prior to the birth of such person.

U.S. territories

The Fourteenth Amendment applies to incorporated territories, so people born in incorporated territories of the U.S. are automatically U.S. citizens at birth.7 FAM 1121.2-1 Definition of Terms Among current U.S. territories, only Palmyra Atoll is incorporated. All U.S. states were created from organized, incorporated territories which no longer exist, except for the successors of the Thirteen Colonies (including Kentucky, Maine, and West Virginia), the Vermont Republic, and the Texas Republic, which joined directly as states.

There are special provisions governing children born in some current and former U.S. territories or possessions, including Puerto Rico, the Panama Canal Zone, the Virgin Islands, Guam, and the Northern Mariana Islands. For example, states that "All persons born in Puerto Rico [between] April 11, 1899, and ... January 13, 1941 ... residing on January 13, 1941, in Puerto Rico ... [and] persons born in Puerto Rico on or after January 13, 1941, ... are citizens of the United States at birth."

According to federal statute, persons born in American Samoa are American nationals but not U.S. citizens. A 2016 ruling by the D.C. Circuit Court upheld the United States government's interpretation that American Samoa is not "in the United States" for purposes of the Fourteenth Amendment and therefore American Samoans are nationals but not citizens at birth.Tuaua v. United States, 788 F.3d 300, 301-02 (D.C. Cir. 2015) ("The judgment of the district court is affirmed; the Citizenship Clause does not extend birthright citizenship to those born in American Samoa."). A 2021 ruling by the 10th Circuit Court similarly upheld the government's position and reversed a lower court ruling that said American Samoan plaintiffs were United States citizens at birth.Fitisemanu v. United States, No. 20-4017, (10th Cir. 2021) ("Such consideration properly falls under the purview of Congress, a point on which we fully agree with the concurrence. These circumstances advise against the extension of birthright citizenship to American Samoa. We reverse.").

Outlying possessions According to persons born (or found, and of unknown parentage, under the age of 5) in an outlying possession of the U.S. (which is defined by as American Samoa and Swains Island) are U.S. nationals but not citizens, unless otherwise provided in section 1401. The U.S. State Department publication titled Historical Background to Acquisition by Birth in U.S. Territories and Possessions explains the complexities of this topic.8 FAM 302.1 Historical Background to Acquisition by Birth in U.S. Territories and Possessions

U.S. waters and airspace A child born in U.S. waters or airspace is a U.S. citizen by birth. See 8 FAM 301.1–4 ("Birth in U.S. Internal Waters and Territorial Sea"), 8 FAM 301.1–5 ("What Is Birth in U.S. Airspace?"), and 8 FAM 301.1–6 ("Documenting Birth in U.S. Waters and U.S. Airspace").

Statute, by parentage Under certain circumstances, children may acquire U.S. citizenship from their parents. The Naturalization Act of 1790 provided for birthright citizenship for children born out of U.S. jurisdiction to two citizen parents. The Naturalization Act of 1795, which increased the period of required residence from two to five years, introduced the Declaration of Intention requirement, or "first papers", which created a two-step naturalization process, and omitted the term "natural born". The Act specified that naturalized citizenship was reserved only for "free white person[s]" and changed the requirement in the 1790 Act of "good character" to read "good moral character". The Naturalization Act of 1798 increased the period necessary for immigrants to become naturalized citizens in the United States from 5 to 14 years.

In 1855, birthright citizenship was extended to children with citizen fathers and noncitizen mothers.10 Stat. 604 In 1934, it was extended to children with citizen mothers and noncitizen fathers.48 Stat. 797 The child would have to fulfill "retention requirements" of residing continuously in the United States for at least 5 years immediately before his or her 18th birthday and taking the Oath of Allegiance within 6 months after his or her 21st birthday. These retention requirements contained in the 1934 statute were repealed by the Nationality Act of 1940 (the "1940 Statute"). From 1940 until 1978, concerning a child born abroad who acquired U.S. citizenship at birth but had only one U.S. citizen parent, both the child and this parent had to fulfill requirements of residing, or being physically present, in the United States or its outlying possessions for a certain number of years before reaching a specified age. Otherwise the child would not retain the U.S. citizenship (hence the name "retention requirement"). The 1952 Statute imposed a revised requirement on any such children to be continuously physically present in the United States for at least 5 years between the ages of 14 and 28 in order to retain citizenship. The retention requirement was changed several times, eliminated in 1978, and subsequently eliminated with retroactive effect in 1994.

Children born overseas to married parents The following conditions affect children born outside the U.S. and its outlying possessions to married parents (special conditions affect children born out of wedlock: see below):

If both parents are U.S. citizens, the child is a citizen if either of the parents has had residency in the U.S. prior to the child's birth If one parent is a U.S. citizen and the other parent is a U.S. national, the child is a citizen, if the U.S. citizen parent has lived in the U.S. for a continuous period of at least one year prior to the child's birth If one parent is a U.S. citizen and the other parent is not a U.S. citizen or national, the child is a citizen if the U.S. citizen parent has been "physically present" in the U.S. (including, in some circumstances, time spent overseas when a parent who is a U.S. government employee is posted overseas) before the child's birth for a total period of at least five years, and at least two of those five years were after the U.S. citizen parent's fourteenth birthday.Immigration and Nationality Act § 301(g); 8 USC § 1401(g). For children born prior to the enactment of Public Law 99-653 on November 14, 1986, the citizen parent's U.S. presence requirement is ten years, of which at least five years had to have been after the parent's fourteenth birthday.

Children born overseas to unmarried parents There is an asymmetry in the way citizenship status of children born overseas to unmarried parents, only one of whom is a U.S. citizen, is handled.

Title paragraph (c) provides that children born abroad after December 24, 1952, to unmarried American mothers are U.S. citizens, as long as the mother has lived in the U.S. for a continuous period of at least one year at any time prior to the birth.

paragraph (a) provides that children born to American fathers unmarried to the children's non-American mothers are considered U.S. citizens only if the father meets the "physical presence" conditions described above, and the father takes several actions: