The situation: it's been 5 years since this person got the GC. He would very much like to continue the life that he has here. His mother who lives in her native country by herself, however, has gotten weak and needs a constant care now. Since he doesn't believe putting a parent into an institution or a "senior home" or things like that, he is thinking about going back to her and taking care of her by himself with help from his family. He could be out of USA for more than two years, in which case even a re-entry permit wouldn't work. Can he come back here if in fact he had to stay out for more than two years? I came across this thing called "Returning Resident Visa". What is it? Is it something he might want to consider?