K-1 visa is for a fiancé(e) who is engaged or contracted to be married to a US citizen in the United States. The marriage must be legally possible according to laws of the state in the United States where the marriage will take place.  The child of a fiancé(e) may receive a derivative K-2 visa from his/her parent's fiancé(e) petition.

In general, the two people must have met in person within the past two years. The Department of Homeland Security's U.S. Citizenship and Immigration Services (USCIS) grants some exceptions to this requirement. For example, it may be contrary in some traditions for a man and woman to meet before marriage, etc.

The US citizen must file the Petition for Alien Fiancé(e),  with the Department of Homeland Security's U.S. Citizenship and Immigration Services (USCIS) office that serves the area where the US citizen lives.  Note: the petitioner cannot file the petition at an embassy, consulate or U.S. immigration office abroad.

After the USCIS approves the petition, it sends the approval directly to the embassy or consulate where the fiancé(e) will apply for a K-1 nonimmigrant visa for a fiancé(e).

The petitioner and the alien fiance(e) must conclude the marriage within 90 days of the allien fiance(e)'s entry to the United States.  The alien fiance(e) must leave the United States IF she/he fails to marry the US citizen petitioner within 90 days.