If you were not born in the U.S. but have at least one U.S. citizen parent

You can acquire U.S. citizenship through a concept known as jus sanguinis, which means "right of blood" in Latin. Under jus sanguinis, citizenship is automatically passed on to a child at birth when one or both of his parents are U.S. citizens. Depending on other factors, there are additional statutory requirements where you must demonstrate residence or physical presence of your parent. We must also look at the law that was in effect on the date of the individual's birthday. Cases involving Assisted Reproductive Technology (ART) for children born abroad offers unique challenges. At least one U.S. citizen parent must have a biological connection to the child in order to transmit U.S. citizenship to the child at birth. In ART cases, parents are required to provide medical and documentary evidence of the child's conception and birth, along with evidence of the parents' identity, citizenship, and physical presence in the United States.

You can also derive citizenship through the naturalization of at least one of your parents

We analyze the law at the time the naturalization took place, along with the age of the person at that time. Before the enactment of the Child Citizenship Act of 2000, both parents were required to naturalize before you turned 18 years old and required you to be living in the United States as a permanent resident (green card holder). As of February 27, 2001, the requirements changed and now you derive U.S. citizenship if:

• Were under 18 years old at the time of one parent's naturalization;
• One parent is a U.S. citizen by birth or naturalization;
• You were admitted as an immigrant for permanent residence (green card); and
• You were living in the legal and physical custody of the U.S. citizen parent.

Also, you must be residing in the United States and intend to continue residing in the country. If you were adopted, the adoption must be full and final.