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

UNLIMITED FAMILY-BASED

Immediate Relatives of U.S. Citizens (IR): The spouse, widow(er) and unmarried children under 21 of a U.S. citizen, and the parent of a U.S. citizen who is 21 or older.

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

Family First Preference (F1): Unmarried sons and daughters of U.S. citizens, and their children, if any. (23,400)

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.

Family Third Preference (F3): Married sons and daughters of U.S. citizens, and their spouses and children. (23,400)

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)

PETITION

Relatives of intending immigrants who plan to base their immigrant visa applications on family relationship must obtain a Form I-130, Immigrant Petition for Relative, from the Bureau of Citizenship and Immigration Services in the Department of Homeland Security (BCIS).  The petitioning U.S. citizen or legal permanent resident must submit the Form I-130 to the BCIS office.  Forms and instructions are available from BCIS.  Once BCIS approves the petition, they will send the petitioner a notice of approval, Form I-797.  BCIS will also forward the approved petition to the Immigrant Visa Processing Center, which will contact the intending immigrant with further information.

VISA INELIGIBILITY / WAIVER

The immigration laws of the United States, in order to protect the health, welfare, and security of the United States, prohibit the issuance of a visa to certain applicants.  Examples of applicants who must be refused visas are those who: have a communicable disease such as tuberculosis, have a dangerous physical or mental disorder, or are drug addicts; have committed serious criminal acts; are terrorists, subversives, members of a totalitarian party, or former Nazi war criminals; have used illegal means to enter the United States; or are ineligible for citizenship.  Some former exchange visitors must live abroad two years.  Physicians who intend to practice medicine must pass a qualifying exam before receiving immigrant visas.  If found to be ineligible, the consular officer will then advise the applicant if the law provides for some form of waiver.