American FactFinder is the online U.S. Census Bureau tool we use to confirm the PSTAT (Sort1) code we use to indicate a patron's legal place of residence. PSTATs are added during a new registration or modified during an address change (as necessary). This tool is currently not available due to the government shutdown.
While this site is unavailable, try to get the most precise information possible from the patron. Assign the most specific code you can and use the "Undetermined" code as necessary. You should keep track of every new registration and address change starting today and then go back and confirm the PSTATs (Sort1) in those records, once funding is restored. Thanks to Madison Central for the heads-up.