Generally

You can qualify for TN classification if you are a Canadian or Mexican citizen who will work as a professional in the U.S. The United States-Mexico-Canada Agreement (USMCA), which entered into force on July 1, 2020, replaced the North American Free Trade Agreement (NAFTA) Treaty. Essentially it's the same. It specifies the list of professional occupations, as well as the corresponding educational and/or licensure requirements. A TN may be valid for up to three years. For Canadian citizens, you can file a petition with U.S.Citizenship and Immigration Services (USCIS) or at select ports of entry. Mexican citizens must apply for TN visas at U.S. consulates abroad, and do not have the option of obtaining a petition approval from USCIS in advance. Dependent spouses and children of TN professionals hold TD (Dependent) status. An extension of TN status for Canadian or Mexican citizens may be filed with USCIS, or the beneficiary may apply for a new period of TN status at aport of entry or at a U.S. consulate abroad.