Main ContentLength of Stay
TN nonimmigrants can be admitted to the United States for an initial period of up to three years and can request extensions of stay for additional three-year periods.
A TN nonimmigrant is not restricted to a cumulative total number of years in TN status; however, multiple extensions under TN status could raise suspicion by U.S. Citizenship and Immigration Services that the employee is seeking more than just a temporary stay.