The INA allows for the immigration of foreigners to the United States based on relationship to a U.S. citizen or legal permanent resident under two basic categories: unlimited and limited.

Unlimited Family-based:
This categoy includes

1. Immediate Relatives of U.S. Citizens (IR):
   • Spouse
   • Widow(er)
   • Unmarried children under 21
   • Parent of a U.S. citizen who is 21 or older
2. Returning Residents (SB):
   • Immigrants who lived in the United States previously as lawful permanent residents and are returning to live in the U.S. after a temporary visit of more than one year abroad.

Limited Family-based:

1. Family First Preference (F1): Unmarried sons and daughters of U.S. citizens, and their children, if any. (23,400)
2. Family Second Preference (F2): Spouses, minor children, and unmarried sons and daughters (over age 20) of lawful permanent residents. (114,200) At least seventy-seven percent of all visas available for this category will go to the spouses and children; the remainder will be allocated to unmarried sons and daughters.
3. Family Third Preference (F3): Married sons and daughters of U.S. citizens, and their spouses and children. (23,400)
4. Family Fourth Preference (F4): Brothers and sisters of United States citizens, and their spouses and children, provided the U.S. citizens are at least 21 years of age. (65,000)