K-1 Visa
From VjWiki - The Immigration Wiki
A K-1 Visa (also known as a Fiance(e) Visa) is a Visa that is issued to a non US Citizen who is engaged to a US Citizen. This is technically a non-immigrant visa and allows for the visa holder to enter the United States for up to 90 days during which time they may get married and file for Adjustment of Status (to become a Legal Permanent Resident of the US). After filing for Adjustment of Status they may reside in the US beyond the 90 day K-1 Visa validity while their Adjustment of Status application is processed.
Background
If your fiancé(e) is not a citizen of the United States and you plan to get married in the United States, then you must file a petition with USCIS on behalf of your fiancé(e). After the petition is approved, your fiancé(e) must obtain a visa issued at a U.S. Embassy or consulate abroad. The marriage must take place within 90 days of your fiancé(e) entering the United States. If the marriage does not take place within 90 days or your fiancé(e) marries someone other than you (the U.S. citizen filing USCIS Form I-129F - Petition for Alien Fiancé), your fiancé(e) will be required to leave the United States. Until the marriage takes place, your fiancé(e) is considered a nonimmigrant. A nonimmigrant is a foreign national seeking to temporarily enter the United States for a specific purpose. A fiancé(e) may not obtain an extension of the 90-day original nonimmigrant admission.
If your fiancé(e) intends to live and work permanently in the United States, your fiancé(e) should apply to become a permanent resident after your marriage. (If your fiancé(e) does not intend to become a permanent resident after your marriage, your fiancé(e)/new spouse must leave the country within the 90-day original nonimmigrant admission.) Please note, your fiancé(e) will initially receive conditional permanent residence status for two years. Conditional permanent residency is granted when the marriage creating the relationship is less than two years old at the time of adjustment to permanent residence status.
Please note: Your fiancé(e) may enter the United States only one time with a fiancé(e) visa. If your fiancé(e) leaves the country before you are married, your fiancé(e) may not be allowed back into the United States without a new visa.
Who is Eligible
U.S. citizens who will be getting married to a foreign national in the United States may petition for a fiancé(e) classification (K-1) for their fiancé(e). You and your fiancé(e) must be free to marry. This means that both of you are unmarried, or that any previous marriages have ended through divorce, annulment or death. You must also have met with your fiancé(e) in person within the last two years before filing for the fiancé(e) visa. This requirement can be waived only if meeting your fiancé(e) in person would violate long-established customs, or if meeting your fiancé(e) would create extreme hardship for you. You and your fiancé(e) must marry within 90 days of your fiancé(e) entering the United States.
You may also apply to bring your fiancé(e)'s unmarried children, who are under age 21, to the United States.
How To Apply For A K-1 Visa
Please see the guide on how to submit for a a K-1 visa: Step-by-Step Guide on How to File for a K-1 Visa for your Foreign Fiance(e)
For more information, see: K-1 Visa Useful Tips and Other Information
