A person may file Form N-600 if they are claiming U.S. citizenship by law while in the U.S. or if they were born abroad to U.S. citizen parents.

You automatically become a U.S. citizen if you meet the following requirements:
- Citizen Parent: At least one parent is a citizen by birth or naturalization.
- U.S. Residence: The individual lives in the U.S. with their citizen parent.
- Legal Admission as Permanent Resident: The individual was legally admitted as a permanent resident.
- Under 18: The individual is still under 18 years old.
- Legal Custody: The individual is a biological child under legal custody of citizen parent before turning 16.

An individual born outside the U.S. to citizen parents may claim automatic citizenship at birth if they meet:
- Both parents are citizens, and one resided in the U.S. before birth.
- Or, if one parent is foreign and the other is a citizen who, before birth, was physically present in the U.S. for at least 5 years (2 after age 14).

A person may also apply if before turning 18 and before 2/27/2001:
- Lived continuously in the U.S. as a legal permanent resident; and
- Both parents, the custodial parent, or the sole surviving parent naturalized as citizens.