In most cases, to be admitted to the United States, you must have a passport that is valid for at least six months beyond the period of your intended stay. So, what can you do if your foreign passport is expiring in less than six months?
Generally, you will not be able to re-enter the United States without a passport that is valid for at least six months beyond the date of your entry. Unless you are a citizen of one of the countries in the “six-month club.”
What’s the “six-month club”? Certain countries have agreements with the United States that allow their citizens to enter on a passport that is valid for less than six months. Citizens from the “six-month club” countries only need to have a passport valid for their intended period of stay. Keep in mind, however, that the person will only be allowed admission up to the actual date of the passport’s expiration.
Additionally, if your expired passport has your current valid visa, you can use that expired passport and visa in conjunction with the new passport to enter the United States.
What if you’re already in the U.S.? In most cases, you may need to delay leaving or re-entering the United States until you have renewed your passport. Several countries allow foreign nationals to apply to renew their passport while in the U.S.
See the latest “six-month club” list in this PDF from US Customs and Border Protection.