Distantlove718

Hi All! My fiancé came to the states on a fiancé visa and after being married for 4 years things are just not working out between us two and we have decided to split. He had the conditional green card and we filed I-751 in may of 2023 and are still waiting for an answer from uscis. If we get divorced now, while we are still waiting for the I-751, will that affect his permanent residency application? What will happen with the application we filed ? Will it just be a RFE to show divorce or will he get denied and have to refile? Also, we were married for 4 years. Will he still be able to apply for naturalization app on approval of I-751 or will he have to wait for the 5 year mark?