International Attendees

We welcome attendees from all over the world! Here’s some information to help you research any visa and travel requirements.

Visa/Passport Information

Helpful Links

If you are traveling to the US from another country, you will need a passport and should check whether you will need to apply for a visa. If so, you should apply as early as possible—at least six months before your intended arrival. If you need a visa, we strongly encourage you to register as soon as possible for the conference to receive your letter of invitation, which is helpful in the visa application.

Citizens of certain countries do not need to apply for a visa to travel to the US. These are known as Visa Waiver Program countries.

All visitors traveling to the US (including from Visa Waiver Program countries) must register online through the Electronic System for Travel Authorization (ESTA) at least three days before they travel. If your ESTA application is authorized, it will be valid for up to two years. DHS recommends that travelers submit an ESTA application as soon as they begin travel plans.

If you are NOT eligible to travel under the Visa Waiver Program you will need to:

  • Apply for a visa at least six months in advance.
  • Provide your entire trip itinerary, including travel to any countries other than the United States, when you apply.
  • If your travel plans depend on early approval of the visa application, you must specify this when you apply.
  • Provide proof of scientific status (e.g., proof that you submitted an abstract for the meeting). Do not wait until you receive a notification that your abstract has been accepted before applying for a visa. It is very rare that an abstract is denied.
  • Provide a link to the meeting website and a copy of your letter of invitation.
  • Provide evidence that you are intending to return to your country of residence. This includes such things as:
    • family ties in your current country of residence;
    • property ownership;
    • bank account;
    • employment contract or statement from employer showing that your position will continue after the dates of the meeting.

Please note that visa requirements vary by passport-issuing country and citizenship (not merely residency).

If you are experiencing significant visa delays, we encourage you to fill out the National Academies visa survey. This allows them to bring your case to the attention of the US Department of State and to track trends in visa issues among the scientific community. If you will be unable to attend TAGC because you cannot obtain a visa in time, please let us know via

Need more information about applying for a visa as a scientist? Please contact the National Academies International Visitors Office.

Letter of Invitation

You may need a letter of invitation from the conference for your visa application. Once you have registered, you can access the letter of invitation through the Registration Resource Center. For security purposes, letters of invitation can only be sent to individuals who have registered for the meeting. Register now to request your letter of invitation.