The earliest you can enter the US is 30 days before your DS-2019 or I-20 begin date. Please consult with ISSS if taking this step. The amount of time needed for processing a change of status can vary between three to five months. This process does not give you a new visa stamp. The next time you travel outside the U.S. you will need to visit a U.S. consulate or embassy to request a new visa stamp that reflects your changed status. Other Concerns.