Filing a Form I-130 petition for an alien relative is the first step in helping that relative become a lawful permanent resident of the United States. As a US citizen, you can petition for your spouse, unmarried children under 21, parents, and unmarried siblings over 21. Approval of the I-130 establishes the family relationship but the relative's place in line depends on when you filed. Wait times vary from immediately available for some immediate relatives to several years for others. The petition process and requirements are outlined on the USCIS website.