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Visa and Invitation Letter


As you know, the requirements for travel to the United States constantly change. The links below can connect you to the latest US Government Visa information. We urge everyone that requires a Visa to travel to the US to apply for the Visa as early as possible, at least 5 months before intended travel. Be accurate and specific in completing your application. Please read the following information carefully.

Invitation Letters

If you require a letter of invitation for your visa application, please write to us at with the Subject: Request for an Invitation Letter.

At least one of the following criteria must be met in order to honor the request for a letter of invitation. The requesting party must either:

  • Be an author of an accepted submission (oral presentation, poster presentation, panel member)
  • Have paid the registration fee, in full, for this conference.
  • Have paid the exposition or showcase fee, in full, for this conference.

Note: We cannot provide visa letters for spouses or guests

Disclaimer: Please note that this content is for general information purposes only. While every effort is made to ensure that the information provided is accurate and up-to-date, regulations may change. The only authoritative sources on U.S. visas are U.S. government websites. Attention: Mat Science 2019 CANNOT intervene with U.S. Embassies or consulates abroad, or with the U.S. State Department on behalf of any member or Mat Science 2019 meeting attendee.

Visa Application Process

What type of visa?
Generally, non-U.S. citizens/residents must obtain a nonimmigrant B-1/B-2 visa to enter the United States for a temporary visit. Visitor Visa Information from the U.S. Department of State

Visa Waiver Program
Under the Visa Waiver Program (VWP), citizens of certain countries may travel to the United States for stays of 90 days or less without a visa. Anyone traveling under VWP must apply for authorization through the Electronic System for Travel Authorization (ESTA). Visa Waiver Program Information Electronic System for Travel Authorization

Set Up Your Visa Interview
If you are not eligible to travel under the Visa Waiver Program, you may be required to appear at a U.S. embassy or consulate for an in-person interview prior to visa approval. There may be long waits to schedule an interview, so start the application process as early as possible. Visa Appointment & Processing Wait Times

What to Bring to Your Visa Interview

  • A valid passport.
  • Online nonimmigrant visa application (Form DS-160) confirmation page.
  • Specific and detailed explanations related to your purpose for travel. Example: Copy of your Mat Science 2019 Letter of Invitation.
  • Complete travel itineraries and schedules if appropriate. Note: Airline ticket proof of purchase is not a required item for documenting your trip itinerary.
  • Proof of an existing relationship with your inviter, Mat Science 2019, or other U.S. entities. Example: Copy of your Mat Science 2019 meeting registration.
  • Explanation of how your visit will be funded.
  • Your CV.

Visa Wait Times
The U.S. Department of State's Bureau of Consular Affairs provides visa wait times for every U.S. Consulate worldwide. Visa Wait Times

Administrative Processing
Some applications require additional "administrative processing" and this adds several weeks to the application process. Applicants involved in scientific fields are often subjected to administrative processing and should apply for visas as early as possible, preferably 3-4 months in advance. Bring your CV and letter of invitation to the visa interview to help facilitate any additional processing. Administrative Processing Information