This form is available to file online. If you meet certain requirements, you may become a US citizen either at birth or after birth.Use this form to apply for US citizenship. Form I-130: Petition for Alien Relative is the first form you must file to start the marriage-based green card application process. Our online service provides step-by-step Form I-130 instructions so that you can fill out the petition in just a few minutes. Permanent residents use Form N-400, Application for Naturalization, to apply for U.S. citizenship through the naturalization process. If you qualify, you must submit the necessary forms, personal documents, and photographs along with a filing fee to a USCIS Service Center. Palm Beach County immigration Attorney William M Cavanaugh can Make the marriage and fiancé visas process for you and your fiancé much easier. Filing under this provision requires proof that the marriage and the U.S. citizen spouse's citizenship are valid. Our expert lawyers can help you prepare and file your N-400 application and prepare for your interview as well.