The K-1 fiance(e) visa is a nonimmigrant visa that serves the purpose of bringing a foreigner to the United States in order to marry a U.S. citizen. The term nonimmigrant means the foreign-born fiancee is coming to the United States temporarily. After the marriage occurs, nonimmigrant status can be adjusted to immigrant status by applying for permanent residency (a green card).
A U.S. citizen (petitioner) must file for the K-1 visa on behalf of his or her foreign-born fiancee (beneficiary). Permanent residents of the United States can't make this petition. Both parties must legally be able to marry. This includes adhering to minimum age requirements for the state in which the marriage is planned, as well as proof that any previous marriages are legally ended (for example, annulment, divorce or spousal death). The couple must have proof of having met at least once within two years prior to the visa application. The U.S. Citizenship and Immigration Services states that the only way around this rule is if "[meeting] would violate strict and long-established customs of [the citizen's] or [the] fiance(e)'s ... culture or social practice," or if the U.S. citizen can demonstrate that adhering to the requirement would result in suffering or "extreme hardship."
The K-1 fiance(e) visa process uses Form I-129F. The application must be filed by the U.S. citizen at a USCIS field office, not at a consulate, embassy or U.S. overseas office. Once the USCIS approves the citizen's application, the National Visa Center processes it and sends it to the fiancee's local U.S. consulate, where the fiancee files a K-1 visa petition in response. The fiancee then goes through an interview process and is required to present a passport valid for at least six months past the intended trip, a birth certificate, fingerprints, police certificates from each resided in town or city after age 16, a medical exam, a vaccination record, proof of relationship to the U.S. citizen (including photographs), divorce decrees or death certificates for previous spouses, and all requested paperwork (Form DS-156 and Form DS-156K). Form I-134, Affidavit of Support, may be required to demonstrate the U.S. citizen can provide for the fiancee.
Once the U.S. government issues a K-1 visa, the fiancee has 90 days in which to travel to the United States and marry the citizen who filed the petition. The visa expires after 90 days, so if the fiancee is unable to travel within the time frame, the application process must be fully repeated in the future. A fiancee who arrives in the United States and doesn't marry within the allotted time period, but remains in the country, is violating U.S. immigration laws. According to the USCIS, such a violation "may result in removal (deportation) and/or could affect future eligibility for U.S. immigration benefits." For marriages that occur within the proper time frame, the foreign-born spouse may then apply for a green card (permanent residency) and is able to legally remain in the United States during the application process.