You should keep your passport valid for 6 months into the future. If you notice that the expiration date on your passport is approaching, go to the State Department's web site at / for a listing of foreign consular offices in the U.S. You may need to send your passport to your consulate in order to renew it. When sending your passport through the mail, it is a good idea to send it by certified mail or by a courier service, such as FedEx or DHL, which will allow you to track your passport. Also be sure to keep your receipt so that you can prove that the passport was sent for renewal.