For B-1 visitors staying less than 90 days (and not conducting research), the UCSF host unit issues the invitation letter (B-1/WB Sample of Invitation Letter).
Visitors from Visa Waiver Countries:
Visitors should first register their visit electronically with Customs and Border Protection before tier trip. Upon arrival they will should present their UCSF invitation letter. A list of visa waiver countries may be found at the U.S. Department of State website.
Visitors from Counties Requiring Visas:
If the visitors do not already posses a B-1/B2 visa stamp in their passport they first need to make an appointment with a local US consulate. A list of US visa issuing posts may be found at the US Embassy website.
After the visitor acquires the B1/B2 visa stamp, they may enter the US in B-1 status after presenting the invitation letter above.
For stays longer than 90 days, or visits that require research, a different visa category should be considered. Information on more appropriate visas ca be found on our How to Invite a Scholar Page.