text: I would recommend consulting with an immigration attorney for a full answer, but here's my experience.\nIf you lose your legal status for one reason or another, you can still be eligible for a Legal Permanent Resident status at a later point. As a matter of fact, the applications asks you the question, whether at some point you were "illegal". Things like that happen, and the expired student visa case is not unique. The key to avoiding legal problems is not leaving the country before obtaining the LPR status.\nHowever, when it comes to leaving and then re-entry, you will have some serious problems. Violation of the legal status can lead to anything from a 3-year to a 10-year bar from obtaining a visa. I have also heard from an attorney of a vast number of cases where people were barred from re-entry permanently. Check Ch. 8, CFR. for more details, or the www.uscis.gov website.