United States law requires that a traveler’s passport be valid for six months beyond the last day the traveler intends to be in the U.S. The effect of this law is that a traveler who is traveling on a passport with less than six month validity may find that the period of authorized entry is limited to coincide with the expiration date of his passport.

To address this issue, the United States has agreements with many countries whereby the U.S. considers those countries’ passports valid for six months beyond their date of expiration. This gives U.S. immigration authorities leeway to authorize a visit that extends beyond the date of expiration, if appropriate.
- All of the countries that participate in the Visa Waiver Program except Brunei have this agreement with the U.S.
- Many other countries have agreements as well. See the list of countries.
http://www.state.gov/documents/organization/104770.pdf
- If your country of nationality is not on the list, you should be certain that your passport is valid for six months beyond the last day you intend to be in the U.S. If necessary, you may wish to obtain a new passport to address any concerns you may have.

* traveling for business, pleasure or transit only.
* staying in the US for 90 days or less.