Citizenship of the United States
A person who is considered a citizen by more than one nation has "dual citizenship". It is possible for a United States citizen to have dual citizenship; this can be achieved in various ways, such as by birth in the United States to a parent who is a citizen of a foreign country (or in certain circumstances the foreign nationality may be transmitted even by a grandparent) by birth in another country to a parent(s) who is/are a United States citizen/s, or by having parents who are citizens of different countries. Anyone who becomes a naturalized U.S. citizen is required to renounce any prior "allegiance" to other countries during the naturalization ceremony; however, this renunciation of allegiance renunciation of citizenship to those countries.
Relinquishment of United States nationality
Additionally, aliens face restrictions on eligibility for payments based on their country of citizenship or residence, whereas U.S. citizens do not. Residents of countries which have a totalization agreement with the United States, as well as citizens of 53 other countries, can receive Social Security payments indefinitely while residing outside of the United States. Otherwise, Social Security benefit payments will stop after the alien has spent six full calendar months outside of United States, and cannot be resumed until the alien spends one full calendar month inside of the United States and is lawfully present for that entire month. U.S. citizens, in contrast, can receive Social Security payments outside of the U.S. regardless of their length of residence abroad.