Travel Visa & Invitation Letter

If you plan to attend the 72nd ASMS Conference on Mass Spectrometry and Allied Topics and will be traveling to Anaheim, CA from countries other than the United States, please be aware of the U.S. passport and visa policies for citizens and visitors. The following information is provided in good faith. It is the attendee's responsibility to verify the information and suggestions below as it applies to his/her visa scenario.

Please look for the section below entitled "Supplemental Information for Visa Application Including Letter of Invitation from ASMS" for more detailed information.

What is a U.S. Visa?

A citizen of a foreign country who seeks to enter the United States generally must first obtain a U.S. visa, which is placed in the traveler’s passport, a travel document issued by the traveler’s country of citizenship.

Certain international travelers may be eligible to travel to the United States without a visa if they meet the requirements for visa-free travel.

Visa Waiver Program (VWP)

The Visa Waiver Program (VWP), administered by the U.S. Department of Homeland Security (DHS) in consultation with the U.S. State Department, permits citizens of 40 countries to travel to the United States for business or tourism for stays of up to 90 days without a visa. In return, those 40 countries must permit U.S. citizens and nationals to travel to their countries for a similar length of time without a visa for business or tourism purposes. It also includes comprehensive vetting of individual VWP travelers prior to their departure for the United States, upon arrival at U.S. ports of entry, and during any subsequent air travel within the United States.

If you are not a citizen of these countries or are not eligible to participate in the VWP, please click here, to find out how to obtain a visa. If you do not have access to the Internet, contact your nearest U.S. Embassy or Consulate for further information.

Supplemental Information for Visa Application Including Invitation Letter from ASMS

You should be prepared to provide supplementary information explaining the purpose of your travel with your visa application. In this regard, the following supplementary information is recommended:

  • A letter of invitation to ASMS 2024. You may request a letter of invitation by sending request to Your invitation request should include the following to appear on your letter: name, address, passport number, and arrival and departure dates (please indicate arrival to and departure from USA, not conference dates). Please be sure the letter of invitation is issued to the name as it appears on your passport and not the name that is in your ASMS membership profile (if they are different). The passport number and arrival/departure dates are optional and at your discretion.
  • If you have submitted an abstract to ASMS 2024, please include your abstract submission confirmation email notice as supplementary information for your visa application. Abstract acceptance notifications will be sent in early March. If your abstract is accepted you may use that notification in lieu of submission confirmation.
  • Please provide a letter from your institution, training director or employer stating that you have been given time to attend ASMS 2024 and are expected back at your place of employment on a specific date. Be sure the letter uses the name that is on your passport.
  • Provide information on your ASMS 2024 conference registration. Again, this would be the email confirmation you receive once you have registered for the conference. Be sure you register with your passport name and that your hotel and airline reservations are also made in the name on your passport.

This supplementary information will demonstrate to the consular officer reviewing your visa file that you are sincere about attending ASMS 2024, to garner both personal and professional benefits from the conference events and sessions, and then return to your country to share this informational gain with your professional counterparts. It is very important that the name on all documentation in your visa application file matches the name on your passport.

Remember that having a U.S. visa allows you to travel to a port-of-entry—an airport, for example—but does not guarantee entry into the U.S. Once you arrive in the U.S., you will need to pass through Customs and Border Protection control.