To sponsor your fiancé(e) for a K-1 visa, you must first be a U.S. citizen and legally free to marry. The process starts with filing Form I-129F with USCIS. After approval, the petition is sent to the U.S. embassy or consulate in your fiancé(e)’s home country. Your fiancé(e) must complete a visa application, undergo a medical exam, attend an interview, and provide supporting documents. Once the visa is issued, your fiancé(e) can enter the U.S., and you must marry within 90 days.