A common misconception is that Green Card holders (lawful permanent residents) can sponsor their siblings for a Green Card. However, this is not true. Under U.S. immigration laws, only U.S. citizens who are at least 21 years old have the ability to sponsor their siblings for permanent residency through the family-based immigration process. Green Card holders do not have this privilege, as their sponsorship options are limited to their spouses and unmarried children. This restriction highlights the difference in petitioning rights between U.S. citizens and Green Card holders.