The good news is that your parents qualify as immediate relatives under immigration law, which means immigrant visas are always available for them. This assumes you're at least 21 year old. In that case, it's fastest to complete the process in the United States, so long as they were lawfully admitted. It might not be a bad idea to talk to an immigration attorney, though, because there may be some issues of intent and you should get a good idea of what the process will look like for you and your parents. Many immigration attorneys offer a free consultation, and you'll have a better grasp on what is involved in this process.
Answered on Oct 22nd, 2013 at 4:57 PM