International Attendees

Updated March 4, 2022.

Please note: All participants at the in-person conference—presenters, attendees, exhibitors, staff members, guests, and vendors—will be required to be fully vaccinated and boosted, if eligible, at least 14 days prior to the start of the meeting. You will be asked for proof of vaccination. Proof of vaccination is your vaccination card (photo is acceptable) from the healthcare provider. Further policies can be found on the Conference Policies page. Before booking your travel to the US, please visit the US State Department’s website for the most up-to-date information.

Helpful Links

FAQs on COVID-19 vaccination and testing requirements

Requirements for air travelers to the US

Travelers prohibited from entering the US

US Visa application procedures and estimated wait times

Visa Waiver Program

National Academies International Visitors Office

Electronic System for Travel Authorization

Requirements for international travel to the United States

As of November 8, 2021, the United States has reopened to fully vaccinated international travelers from most countries. GSA advises scientists traveling to the US to stay up-to-date on the latest international travel requirements.

Vaccination requirements 
Effective November 8, 2021, all non-immigrant, non-citizen air travelers (with limited exceptions) are required to be fully vaccinated and to provide proof of vaccination prior to boarding a flight to the United States.

COVID-19 testing requirements

As of December 6, 2021, air travelers aged two and older, regardless of nationality or vaccination status, are required to show documentation of a negative viral test result taken within one day before boarding their flight to the United States. If you require a test to board your return flight, there will be onsite testing available at the Town & County. You will need to reserve your testing appointment by April 5. Learn more on the Conference Policies page.

Travelers prohibited from entering the US
A Presidential Proclamation issued on November 27, 2021 prohibits some travelers from entering the United States regardless of their vaccination status. With specific exceptions, travelers who were physically present within certain Southern African countries (as listed on the CDC’s website) during the 14-day period preceding their entry or attempted entry are not permitted to enter the US. Please refer to the Proclamation for the full list of exceptions, including those for United States citizens.

Visa Applications

All visitors traveling to the US (including from Visa Waiver Program countries) must register their details online at least three days in advance of travel. The Department of Homeland Security (DHS) Electronic System for Travel Authorization (ESTA) is a free, automated system used to determine the eligibility of visitors to travel to the United States. It collects the same information as the paper I-94W form you usually complete when traveling to the United States. ESTA applications may be submitted at any time prior to travel, provided it is three days in advance of travel. An ESTA authorization generally 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, at the time of visa application.
• If your travel plans depend on early approval of the visa application, you must specify this at the time of the application.
• Provide proof of scientific status. For example, proof that you submitted an abstract for the meeting. Do not wait until you receive 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 current country of residence;
  • property ownership;
  • bank account;
  • employment contract or statement from employer showing that position will continue after the dates of the meeting.
• 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.

Visa questions should be directed to the National Academies International Visitors Office: visas@nas.edu.

Letter of Invitation

Customized letters of invitation will be available to those who have registered for the meeting or submitted an abstract. A link to request your letter of invitation will be provided in your confirmation. For security purposes, letters of invitation can only be sent to individuals that have registered or submitted an abstract for the meeting.