OPTION #1: You may file for a Certificate of Citizenship if all of the following occurred before your 18th birthday and prior to February 27, 2001: you regularly resided in the U.S. after admission as a Lawful Permanent Resident, AND both of your parents, the parent having legal and physical custody of you, or your sole surviving parent, naturalized as a U.S. citizen.
OPTION #2: If you are the natural born child of a U.S. citizen, you were born outside the United States and you are claiming citizenship by having been born to U.S. citizen parent(s), you automatically become a U.S. citizen at birth if: You were born to two U.S. citizen parents and at least one of your parents had a residence in the United States or one if its outlying possessions. This residence had to have taken place prior to your birth; OR you were born to parents, one of whom is an alien and the other a U.S. citizen who, prior to your birth, had been physically present in the United States or one of its outlying possessions for a period or periods totaling not less than five years, at least two of which were after the age of 14 years.
OPTION #3: If you are the biological or adopted child of a U.S. citizen, you were born outside the United States, and you are claiming citizenship by action of law, you automatically become a U.S. citizen if: you have at least one parent who is a U.S. citizen, whether by birth or naturalization; AND you regularly reside in the United States in the legal and physical custody of your U.S. citizen parent; AND you have been lawfully admitted for permanent residence AND you have not yet reached your 18th birthday; AND you are a biological child, you were legitimate, or you were legitimated while in the legal custody of your legitimating parent(s) prior to reaching your 16th birthday; or You are a biological child born out of wedlock and you have not been legitimated and your mother naturalizes as a U.S. citizen.
OPTION #4: If you are now over the age of 18, but all of the above conditions applied to you before your 18th birthday AND you were under the age of 18 on February 27, 2001.
OPTION #5: May be eligible if one of your parents was a U.S. citizens at the time of your birth.