The TN visa category was created by the North American Free Trade Agreement (NAFTA) between the United States, Canada, and Mexico. The TN visa can be a convenient option for U.S. employers to employ professionals who are citizens of Canada and Mexico in specific, pre-defined job categories, especially when H-1B visas are in short supply.
Most TN Professionals are required to hold a Bachelor's degree or Licenciatura degree in an eligible profession. In addition, if the state in which the professional will work requires a state license to practice (i.e. lawyer, doctor), then the TN professional must possess that credential as well.
TN Professionals who are citizens of Canada and Mexico are allowed to stay in the United States for renewable periods of up to three years at a time.
The list of professions eligible for TN status is available online at: