Naturalization Under The Child Citizenship Act Of 2000
If the child is not eligible for transmission of citizenship because the parent does not meet the physical presence requirements OR because the child is adopted, then the child may acquire U.S. citizenship automatically under the Child Citizenship Act of 2000. The requirements are that the child be under age eighteen, have at least one U.S. citizen parent, and be residing in the U.S. in the legal and physical custody of the U.S. citizen parent after entering the U.S. with an immigrant visa If the child is adopted, the additional requirement is that the adoption be final. Immediately upon fulfilling the last of these requirements (usually entry into the U.S. with the immigrant visa) the parent and child can go directly to a Passport Agency, post office or courthouse authorized to accept passport applications and immediately apply for the U.S. passport. There is no waiting period, nor is there any involvement with U.S. Citizenship and Immigration Services. The child is considered to have acquired U.S. citizenship as of the date of the fulfillment of the last of the requirements, not as of birth.
The child may at a later date apply to a U.S. Citizenship and Immigration Services office for a Certificate of Citizenship as additional documentation of citizenship, but it is not a requirement. One caveat to this process is that to qualify for an immigrant visa, there must be an intention, along with steps taken in furtherance of that intention, for the child to reside permanently in the U.S.
Please see the Immigrant Visa section of the website for additional information on filing an immigrant visa petition.