Foreign nationals who are interested in pursuing U.S. citizenship should check to see whether they may have it already through acquisition or derivation. While acquisition involves being born to a U.S. citizen, derivation involves being a child of a foreign national who became a U.S. citizen before the child turned 18. Derivation became easier to achieve after February 26, 2001, when the Child Citizenship Act went into effect. If you were 18 or younger on or after February 27, 2001, this federal law will apply to your situation.
If you meet the requirements for derivation, you are automatically a U.S. citizen, even if you do not have legal documentation of your status. However, you should seek proof of your status from the government by applying for a Certificate of Citizenship. This will allow you to get a U.S. passport and receive other benefits of citizenship.
Rules for Derivation Under the Child Citizenship Act
You will be eligible to derive citizenship from a U.S. citizen parent if you can meet a series of requirements under the Child Citizenship Act. You must be unmarried and under 18, and you must have at least one parent who is a U.S. citizen. Also, you must have a green card, which means that you are a legal permanent resident of the U.S., and you must be currently living in the U.S. in the legal and physical custody of your U.S. citizen parent.
You do not need to satisfy all of these requirements immediately. You might meet all of them except for the green card requirement, for example. In that case, you could get citizenship through derivation if you successfully complete a green card application and join your parent in the U.S. Or you might meet all of the requirements except having a U.S. citizen parent. If your parent currently has a green card, and then they become a U.S. citizen before you turn 18, you will automatically become a citizen through derivation on that date. If an individual no longer meets the requirements, such as when they are over 18 and living outside the U.S., they may already have received citizenship through derivation if they previously met all of the requirements at the same time. You cannot lose citizenship through derivation unless you voluntarily renounce it, so you still would be a U.S. citizen.
The rules above apply to biological children of U.S. citizen parents. Read more here about derivation and acquisition for adopted children. Additional requirements apply to children who are illegitimate if their only U.S. citizen parent is their father.
Legitimation and Derivation
If you were born to unmarried parents, and only your father became a U.S. citizen, your father would need to have legitimated you before you turned 16. The rules for legitimating a child vary in different countries. The most common way to legitimate a child is to sign the child’s birth certificate, but a father also can sign a statement of paternity or register in the birth records of their country as the child’s father. Other ways include marrying the mother of the child within a certain period after the birth, paying support for the care of the child, establishing paternity through DNA testing, or representing to others that he is the father of the child. This might involve taking the child into his home or fulfilling the role of a father in the child’s activities.