Family-based immigration
1. First Preference
Unmarried sons or daughters of United States citizens. (i.e, those who are 21 years of age or older).
2. Second Preference
a) Spouses or children of an alien lawfully admitted for permanent residence;
b) Unmarried sons or unmarried daughters of an alien lawfully admitted for permanent residence.
3. Third Preference
Married sons or daughters of citizens of the U.S.
4. Fourth Preference
Brothers or sisters of citizens of the U.S., if such citizens are at least 21 years of age.