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 Jose will vote on a site for the 2019 NASFiC. (Worldcon sites are selected two years in advance, and NASFiC sites one year in advance.) See the NASFiC Bids page for information about groups bidding to host the 2019 NASFiC.