The Green Card for Family Preference Immigrants (F4 category) is a U.S. immigrant visa that allows siblings of U.S. citizens to obtain permanent residency. To qualify, the sponsoring U.S. citizen must be at least 21 years old and must file a Form I-130 (Petition for Alien Relative) on behalf of their sibling. The F4 category also includes the sibling’s spouse and unmarried children under 21 as derivative beneficiaries. Since the Family Preference Green Card system is subject to annual numerical limits, F4 applicants often face long waiting periods, sometimes spanning several years, depending on visa availability and their country of origin. Once a visa number becomes available, the applicant can proceed with consular processing or adjustment of status to obtain a Green Card.