The U.S. Congress created the K-3 visa category in the year 2000 in an effort to reunite U.S. citizens and their foreign national spouses and children while their immediate relative petitions are being processed. Petitioners seeking to apply under this category may file an I-129F petition for the K-3 visa after filing an I-130 petition for the IR-1 or CR-1 visa.

Minor children (unmarried and under 21 years of age) of a K3 applicant may derive immigration benefits from the same I-129F petition and be issued a K4 visa. These children CANNOT derive benefits from the same I-130 petition as their birth parent, and so petitioners will need to make sure to file separate I-130 petitions for each stepchild.

If an I-130 for the spouse is already overseas at a U.S. Embassy or Consulate, then the applicant will seek an immigrant visa instead of the nonimmigrant K visa. If an immigrant visa based upon the I-130 for the spouse has already been denied, then neither the spouse nor the spouse's children may qualify for a K3 or K4 visa.