What if your parent naturalized but officially became a U.S. citizen after you turned 18 years of age? If you are a permanent resident in the U.S. or even a foreign national living abroad, there may be a path for you to become a U.S. citizen as well.
Permanent resident
If your parent’s naturalization date is on or after your 18th birthday, you cannot derive citizenship through that parent. However, as a lawful permanent resident, you may file your own naturalization application once you meet the requirements. You may generally file Form N-400, Application for Naturalization, once you meet the citizenship requirements.
Immigration through Parent
If one of your parents became a U.S. citizen after you turned 18, your parent can petition for you as an adult child of a U.S. citizen using Form I-130. The U.S. citizen parent files Form I-130, Petition for Alien Relative. Adult children fall into either the F1 or F3 family preference categories (depending on their marriage status). The immigration process for these categories can be lengthy (several years). Immigration results in permanent resident status (green card). After immigrating and fulfilling naturalization requirements, you too can apply to become a citizen through the regular naturalization process