Attendee Travel

The ASTRO Annual Meeting is the world's premier gathering for the radiation oncology community. We welcome our international attendees and would like to serve as a resource for assistance with travel plans, documentation and all the details for your journey to the United States. We look forward to seeing you at the 2023 ASTRO Annual Meeting!

Plan Your Trip

International attendees have full access to ASTRO’s Annual Meeting Portal, which has a host of resources to make it easier to plan your time in San Diego. Visit the “Transportation and Parking” and “Shuttle” sections in the Annual Meeting Portal to learn about airport transportation options and ASTRO’s shuttle service to the San Diego Convention Center. Be sure to use our official housing reservation system with SPARGO Housing to book a hotel room for your stay. Special hotel room blocks have been arranged. Once you register for the conference, more information on hotels will be included in your registration confirmation.

Travel Information

The 2023 ASTRO Annual Meeting will be hosted at the San Diego Convention Center in San Diego. The San Diego Convention Center is located in downtown San Diego. Located just outside the Convention Center is the Gaslamp Quarter, an urban playground offering lodging, dining, shopping and entertainment options all within a single square-mile. The Embarcadero, located on the west side of the Convention Center, offers breezy walks along the bay and several grassy parks to enjoy For more information on San Diego attractions, restaurants and more, please visit area attractions.

Travel Advisories

For travel to the U.S., please visit the U.S. State Department International Travel website. Please be mindful of advisories prior to booking and registering for the 2023 ASTRO Annual Meeting.

For the latest travel advisories for the state of California and other U.S. cities and states, please visit the Centers for Disease Control travel planner website.

Travel from Outside the United States

At this time, non-U.S. citizens are required to show proof of being fully vaccinated against COVID-19 before boarding a flight to the United States from a foreign country. Travel guidance is subject to change at any time. International attendees are encouraged to check current travel restrictions by visiting the CDC website and country-specific COVID-19 requirements provided by the U.S. Department of State.

For more information please visit the U.S. State Department COVID-19 Travel information website.

Visa Process

Most citizens of foreign countries will need a visa to enter the United States. Please note that it may take up to three months to obtain a visa. For more information about obtaining a visa, please visit the U.S. State Department website. To receive your visa letter, you must be registered and paid in full before you can download your letter. To inquire about letters of invitation, please contact the ASTRO Registration Center.

Do you need a visa?

The Visa Waiver Program permits citizens of certain countries to travel to the United States for business or tourism for stays up to 90 days without a visa. Visa Waiver Program travelers are required to apply for and obtain approval authorization via the Electronic System for Travel Authorization (ESTA) prior to traveling to the United States. To learn more about how to apply for ESTA authorization, visit the U.S. Customs and Border Protection website.

We encourage non-U.S. travelers who need a visa to enter the United States to begin the visa application process as soon as you register for the Annual Meeting. The application and interview process varies from country to country and can take up to 90 days to complete. After you register for the ASTRO Annual Meeting, you will be provided a link where you may download a visa letter of invitation.

When does your U.S. visa expire?

If the traveler already has a U.S. visa appropriate for this travel, check the expiration date on the visa to make sure that it will not expire before the planned travel date.

When does your passport expire?

In order to obtain a U.S. visa, your passport must be valid for at least six months beyond your period of stay in the United States, unless exempt by country specific agreements.

When should you apply for a U.S. nonimmigrant visa?

Non-U.S. citizens should apply for a U.S. Nonimmigrant Visa at least 90 days before their anticipated travel date. Visa processing times vary from country to country and can change depending on the time of year. Visit the U.S. Department of State website for average processing and wait times.

Recent media reports have indicated that the administration has instructed U.S. Consulates to request additional documentation from applicants for visas to the United States. This may include information concerning travel and work history as well as other details. We encourage travelers to familiarize themselves with these reports and factor in additional time for visa processing. For the latest information on U.S. visas, please visit the U.S. Department of State website.

How should you apply for a U.S. nonimmigrant visa?

Visit the website of the local U.S. Embassy or Consulate in your country to find out the process for applying for a U.S. visa, and how long it will take.

Additional planning time beyond the guidelines above may be needed for visa applicants applying at some embassies because of the time required to schedule an interview appointment. Additionally, the wait times for a Nonimmigrant Visa do not include time for required security clearances or administrative processing, which may extend beyond the general timeframe guidelines.

For more information about obtaining a visa, please visit the U.S. Department of State website.

Visa Application Tips

  • Include a letter of invitation from the meeting organizer.
  • When possible, provide proof of professional scientific and/or educational status, society membership and/or meeting registration.
  • Visa applicants are expected to provide evidence that they intend to return to their country of residence. Therefore, applicants should provide proof of binding or sufficient ties to their home country or permanent residence abroad.
  • All applicants must be able to qualify for a visa on their own merits under the requirements of the Immigration and Nationality Act.
  • Learn more about applying for a visa.


While ASTRO believes this information is correct, it is being provided only as a free convenience to assist our international attendees. In no event will ASTRO accept any responsibility with respect thereto. International attendees are encouraged to periodically check the relevant U.S. government sources for the latest information and to conduct their own research into visa requirements. Nothing herein constitutes legal advice. If you have any specific questions regarding the type of visa you should be seeking, visa application process and/or have specific concerns, we advise you to contact a U.S. immigration law attorney and seek specific legal advice.

American Society for Radiation Oncology
251 18th Street South, 8th Floor
Arlington, VA 22202
Telephone: 703-502-1550


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