One of the avenues through with immigrant may apply for lawful permanent residence (LPR) in the United States is through family-based immigration. Eligible foreign nationals may apply for LPR with the sponsorship of a relative who is U.S. citizen or lawful permanent resident. Upon approval of a Form I-130, Petition for Alien Relative, and a Form I-864, Affidavit of Support, to the United States Citizenship and Immigration Services (USCIS), the petition for an immigration visa files in queue with the State Department for a visa number. Once a visa number is issued, if the immigrant is already in the U.S., he may file a Form I-485, Application to Register Permanent Residence or Adjust Status, or if the immigrant is outside of the U.S., he may go to his local U.S. Consulate to complete the process. Visa numbers are issued by the State Department through a preference system through which petitions are prioritized based on the sponsor's citizenship and the type of relationship claimed in the Form I-130. Immediate family members of U.S. citizens, including parents, spouses and unmarried children, are exempt from the preference system and receive visa numbers immediately.