The U.S. Citizenship and Immigration Service has the authority to grant green cards, or permanent resident visas, to aliens, giving them the right to live and work in the United States. There are several ways to obtain a green card, some of which are more difficult than others. An immigration attorney with green card experience can help you determine if you are eligible to become a permanent resident and which qualification route is most appropriate for you and/or your family members. Your attorney can then guide you through the application process. Green card law firms can also work with immigrants who need assistance renewing or replacing a green card, or removing restrictions attached to their permanent residency visa.