United States citizens do not need a U.S. visa or passport for travel to Colorado.
If you are not a U.S. citizen, you may need a visa for entry into the U.S., and may also need a letter from ICOPS 2018 to verify your attendance at the conference. Some embassies may need to verify that registration fees have been paid in full and may require applicants to appear in person for an interview, causing delays in the application process. Applicants affected by these procedures are informed that additional screening is needed. Therefore, attendees should apply for a visa no later than three months prior to the conference, and earlier if possible!
When you submit an abstract, check the appropriate box if you would like to request a letter of invitation to attend the conference once your abstract has been accepted, which may be useful in obtaining a visa. Once you register for the conference, you can download a separate letter indicating that you will be attending.
For additional information regarding visas and/or passports, please visit https://travel.state.gov/content/travel/en/us-visas.html
This website will be updated if more information becomes available.