One topic that consistently comes up in the expat community is acquiring US citizenship for children born abroad to US citizen parents who have not lived in US territory sufficient time for their children to have acquired US citizenship at birth, if the birth took place outside the US.
The legal requirement for a child born outside the US to be a US citizen at birth is that at least one parent is a US citizen who can document a physical presence in the US for at least five (5) years, two of which must be after the age of fourteen (14). The physical presence does not have to be consecutive, but a cumulative total of five years. If you believe that your son or daughter someday may have children born outside of the US, then start documenting the time they spend in US territory as this can have important implications in the future. Passport stamps, flight records, church/school/camp records, doctor/dentist appointments, etc. are examples of such records. Three of the five requisite years can be accumulated prior to their fourteenth birthday.
If the adult US citizen does not have the residency requirement, but wants their child/ren to have US citizenship, then the US citizen grandparent can convey citizenship to the child/ren. Section 322 of the Immigration and Naturalization Act (INA) allows for a child to acquire US citizenship through a grandparent, if the parent cannot convey citizenship directly. The grandparent must be a US citizen who meets the physical presence requirement of at least five (5) years, two (2) of which must be after the age of fourteen. The application, Form N-600K, must be submitted to USCIS, along with birth certificates, proof of residency of the petitioning adult and the filing fee. The interview will take place in the US, with the exception of a US military dependent, and the process MUST be completed prior to reaching his/her 18th birthday. Processing times may vary, so while it may only take a few months, it is advisable to submit the application and supporting documents with at least a year prior to the child’s 18th birthday, or much earlier. Children under the age of 14 will most likely not be required to take the Oath of Allegiance, however, the child will be required to appear for an interview.
The child can apply for a visitor visa once the interview in the US has been scheduled. A certificate of citizenship will be issued and the child will be eligible to apply for a US passport.
Source for further information:
INA 322 https://www.uscis.gov/