New U.S. Government Entry Requirement for Visa Waiver Program (VWP) Countries
Effective 20 January 2011 citizens of Visa Waiver countries will be unable to enter the United States without Electronic System for Travel Authorization (ESTA) approval from the U.S. Government. VWP travelers who have not obtained approval through ESTA will be denied boarding on any air carrier destined for the United States. For more information, visit the VWP program website.

Visa applicants from many countries must now apply 3–4 months in advance of their travel date. The U.S. Department of State maintains a comprehensive website containing information about traveling to the United States.

The National Academies website has additional information about visa-related issues and travel information for U.S. citizens and non-U.S. citizens.

Letters of Invitation

If you submit an abstract to the Fall Meeting  and live in a country other than the US or Canada, a letter of invitation has been prepared and e-mailed to you.  You may access your letter for downloading and printing, by logging-in to the abstract submission site.  After logging-in, click the Submission tab and find your abstract.  Click theView E-mail button next to your abstract to view a copy of the email sent to you, along with a personalized website to your Letter of Invitation.