If you are inside the U.S., file Form I-90. Detailed instructions are on the form.

A person who is automatically granted another citizenship does not risk losing U.S. citizenship. However, a person who acquires a foreign citizenship by applying for it may lose U.S. citizenship. In order to lose U.S. citizenship, the law requires that the person must apply for the foreign citizenship voluntarily, by free choice, and with the intention to give up U.S. citizenship. The U.S. Government does not encourage dual nationality because of the problems it may cause. Claims of other countries upon dual-national U.S. citizens can place them in situations where their obligations to one country are in conflict with the laws of the other. In addition, their dual nationality may hamper U.S. efforts to provide protection to its citizens when they are abroad, especially in the country of their other nationality.

U.S. employers must check to make sure all employees, regardless of citizenship or national origin, are allowed to work in the United States. If you are not a citizen or a lawful permanent resident (immigrant), you may need to apply for a work permit, formally called an "Employment Authorization Document" (EAD), to prove you may work in the United States.

If you are a lawful permanent resident (or conditional permanent resident) and will be outside of the U.S. for more than a year, you will need to make special preparations for your re-entry, before you leave the U.S. If you have applied to adjust to permanent resident status, you should be careful of any trip outside the U.S.

A baby born abroad to U.S. citizen parent(s) should be reported as soon as possible to the nearest U.S. embassy or consulate.

If you were born in a foreign country to a U.S. citizen parent or parents, and your parent registered your birth at a U.S. embassy or consulate, you should request a copy of the Consular Report of Birth.