There are a variety of ways in which U.S. citizens can expatriate or lose their citizenship. Over the years, Congress has passed laws providing for expatriation. For example, in 1868, Congress passed a law which held that deserters were considered to have abandoned their citizenship. A few years later, in 1868, Congress declared the right of all U.S. citizens to renounce their citizenship.

Under the Immigration and Nationality Act, there are seven acts which can result in loss of citizenship:

  • Obtaining naturalization in a foreign country after reaching 18 years of age;
  • Taking an oath or making a formal declaration of allegiance to a foreign country after reaching 18 years of age;
  • Entering, or serving in, the armed forces of a foreign country if such armed forces are engaged in hostilities against the United States, or if such persons serve as a commissioned or noncommissioned officer;
  • Accepting, serving in, or performing the duties of any office, post, or employment in a foreign country after reaching 18 years of age, if the person has or acquires the nationality of such country;
  • Accepting, serving in, or performing the duties of any office, post, or employment in a foreign country after reaching 18 years of age, for which such office, post, or employment, an oath, affirmation, or declaration of allegiance is required;
  • Making a formal renunciation of citizenship before a diplomatic or consular officer of the United States in a foreign state;
  • Making a formal renunciation in writing in the United States, whenever the United States shall be in a state of war and the Attorney General approves that the renunciation is no contrary to the national defense; or,
  • Committing any act of treason against, or attempting by force to overthrow, or bearing arms against the United States, violating, or conspiring to violate certain provisions of the law by engaging in a conspiracy to overthrow, put down, or to destroy by force the government of the United States, or to levy war, if and when the person is convicted by a court martial or by a court of competent jurisdiction.

The burden to establish loss of citizenship rests upon the person who alleges that such has occurred and must be established by a preponderance of the evidence. There is a presumption in the law that a person who has performed any of the acts described above has done so voluntarily. However, this presumption can be rebutted and the citizen must prove that he committed the acts under duress. The person seeking to prove loss of citizenship must also establish that the citizen had the intention of relinquishing his citizenship at the time he performed the expatriating acts.

In 1990, the Department of State created an administrative presumption that most U.S. citizens who commit acts of expatriation actually do so with intent to retain their citizenship. The implementing regulations hold that U.S. citizens will be considered to retain their citizenship in three situations: 1) when he obtains naturalization in a foreign country; 2) when he subscribes to routine declarations of allegiance to a foreign country; and, 3) when he accepts non-policy level employment in another country. If the person affirmatively states that it was his intention to relinquish in any of these situations, then he will lose his U.S. citizenship. In all other cases, the consular officer must determine whether there is evidence of intent to relinquish citizenship when performing the expatriating act.

Dual citizenship

If a person has two or more nationalities, he is considered a dual national. Most countries adhere to the principles of nationality by descent (jus sanguinis), nationality by birth within the territory (jus solis), or a combination of these two models. Thus, it is not uncommon for someone to hold citizenship in one country because he was born there and also from the country where his parents were born. Dual citizens in the United States are not required to choose one or the other of their nationalities, unless specifically required by statute. Persons who obtain their citizenship through naturalization in the U.S. can also acquire dual citizenship, despite the requirement under U.S. law that they renounce all foreign allegiances.