A US citizen can also petition for a visa for non-immediate relatives. Non-immediate relatives will fall into five categories:

Family First Preference (F1): Unmarried sons and daughters of U.S. citizens that are over 21 years of age, and their children, if any.
Family Second Preference (F2): Spouses, minor children, and unmarried sons and daughters (over 21) of lawful permanent residents.
Family Third Preference (F3): Married sons and daughters of U.S. citizens, and their spouses and children.
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.

The filing date of a petition becomes the applicant’s priority date. A visa number becomes available for a preference petition when its priority date becomes current. Immigrant visas cannot be issued until an applicant’s priority date is reached. In certain heavily oversubscribed categories, there may be a waiting period of several years before a priority date is reached. Check the Visa Bulletin for the latest priority dates.

Note: Grandparents, aunts, uncles, in-laws and cousins cannot sponsor a relative for immigration.

Requirements

• Sponsoring U.S. citizen or U.S. legal permanent resident must file an I-130 Petition.
• Documents establishing family relationship must also be submitted with the I-130 Petition.

All Family Preference petitions except the Family Second Preference (F2) petition can only be filed by U.S. citizens. The F2 petition can be filed by legal permanent residents.