The Canadian and Mexican NAFTA Professional (TN) Visa is a special category of visa that allows qualified professionals from Canada and Mexico to work in the United States temporarily. This visa program was established under the North American Free Trade Agreement (NAFTA) and continues under its successor, the United States-Mexico-Canada Agreement (USMCA). 

Key features of the TN Visa: 

1. Eligible Professions: The TN visa is available to professionals who work in specific occupations listed in NAFTA’s Appendix 1603.D.1. These professions include but are not limited to engineers, scientists, accountants, lawyers, nurses, and educators. 
2. Citizenship Requirement: Only citizens of Canada and Mexico are eligible to apply for TN visas. Permanent residents or citizens of other countries are not eligible. 
3. Temporary Status: TN visa holders are granted temporary status in the United States, allowing them to work in their respective professional fields for U.S. employers. The initial period of stay is typically up to three years, with the possibility of extensions. 
4. Job Offer Requirement: To obtain a TN visa, applicants must have a job offer from a U.S. employer in a qualifying profession. The employer must provide a letter of employment specifying the terms of employment and the professional category under which the applicant is eligible. 
5. Qualifications: Applicants must meet the specific educational and professional qualifications required for their respective professions. They must demonstrate that they possess the necessary credentials and expertise. 
6. No Labor Certification: Unlike some other employment-based visas, the TN visa does not require a labor certification process, which streamlines the application process. 
7. Family Accompaniment: Dependents of TN visa holders, including spouses and unmarried children under the age of 21, can accompany them to the United States under the TD (Trade Dependent) visa category. TD visa holders are not allowed to work but can study while in the U.S. 
8. Renewal: TN visa holders can apply for extensions to continue working in the U.S. if they meet the eligibility criteria. There is no specified limit on the number of extensions, but the visa is issued in increments of up to three years. 
9. NAFTA to USMCA Transition: While NAFTA has been replaced by the USMCA, the provisions related to the TN visa category remain largely unchanged. Therefore, the same opportunities and requirements apply to Canadian and Mexican professionals under the USMCA. 

The TN visa program provides a valuable opportunity for professionals from Canada and Mexico to gain work experience in the United States, contributing to the exchange of talent and expertise among the North American countries. It’s important for applicants to thoroughly understand the eligibility criteria and requirements specific to their profession when considering this visa category. Consulting with an immigration attorney experienced in TN visas is advisable to ensure a smooth application process.