How often does the traveler have to update information in EVUS?

An information update is referred to as an enrollment.  Enrollments generally last for two years or when the traveler’s visa or passport expires, whichever comes first. Chinese holders of 10-year  B1/B2, B1 or B2 visas will need to update their information before they intend to travel to the United States (if a two-year enrollment has expired), or when they get a new passport.