A NASFiC is held in North America in any year where the Worldcon is outside of North America.
Currently, there are no seated NASFiCs. Because the 2019 Worldcon will be outside of North American, members of the 2018 Worldcon in San José, California will vote on a site for the 2019 NASFiC. (Worldcon sites are selected two years in advance, and NASFiC sites one year in advance.)
The election to select the 2019 NASFiC will be administered by Worldcon 76 San José. You must be at least a supporting member of Worldcon 76 in order to vote on where the 2019 NASFiC will be held. You can vote by mail in advance of the convention or in person at Worldcon 76. You do not have to attend Worldcon 76 in order to vote. Voting will open later in 2018 at a date yet to be announced and will be open through the afternoon of Saturday, August 18, 2018. The results of the election will be announced at the WSFS Business Meeting on the morning of Sunday, August 19, 2018, in San José. See the WSFS Site Selection page on the Worldcon 76 web site for more information about site selection.
See the NASFiC Bids page for information about groups bidding to host the 2019 NASFiC.