text: what u.s. government agency keeps track of citizenship? specifically, if a law were passed that required citizens to vote in order to retain their citizenship, what government agency would administer this? also, any opinions on the above law? well, this is a tough one... there's a couple agencies that track different aspects to citizenship; there isn't a us citizenship office per se.   the state department manages the "department of state’s bureau of consular affairs" which issues and manages us passports.  the census bureau, a division of the u.s. department of commerce.  without a "domestic passport" issued to all us citizens (similar to the old russian domestic passport) there isn't an accurate way to track this.