Citizen Parent(s) Citizenship Concerns
A child born abroad to two U.S. citizen parents in wedlock acquires U.S. citizenship at birth, provided that one of the parents resided in the U.S. prior to the child's birth. No specific period of time for such residence is required.

A child born abroad to one U.S. citizen parent and one alien parent in wedlock acquires U.S. citizenship at birth, provided the citizen parent was physically present in the U.S. for the time period required by the law.

Reporting the Birth to Establish Citizenship
The birth of a child abroad to a U.S. citizen parent(s) should be reported as soon as possible to the nearest U.S. embassy or consulate to establish an official record of the child's claim to U.S. citizenship at birth. The official record is a Consular Report of Birth of a Citizen of the United States of America, or Form FS-240. This document, known as the Consular Report of Birth Abroad, is a basic United States citizenship document. An original FS-240 is furnished to the parents at the time the registration is approved. A Consular Report of Birth can be prepared only at a U.S. embassy or consulate. It cannot be prepared if the child has been brought back into the United States (although a different document may be requested – see the next two paragraphs), or, if the child is 18 years of age or older at the time the application is made.

If the child returns to the U.S. without a Form FS-240 being filed, an application may be made for a Certificate of Citizenship. Obtaining this certificate involves presentation of basically the same documentation required to obtain a Consular Report of Birth. Under law, the Consular Report of Birth and the Certificate of Citizenship are equally acceptable as proof of citizenship. File Form N-600 (Application for Certificate of Citizenship) with your nearest USCIS office.

A U.S. passport is also proof of citizenship.