The North American Free Trade Agreement (NAFTA) created special economic and trade relationships for the United States, Canada and Mexico. The TN nonimmigrant classification permits qualified Canadian and Mexican citizens to seek temporary entry into the United States to engage in business activities at a professional level.
Among the types of professionals who are eligible to seek admission as TN nonimmigrants are accountants, engineers, lawyers, pharmacists, scientists, and teachers. You may be eligible for TN nonimmigrant status, if:
If you are a Mexican citizen, then you are not required to file a petition with USCIS. However, you are required to obtain a visa to enter the United States as a TN nonimmigrant. You should apply for a TN visa directly at a U.S. embassy or consulate in Mexico. See the Department of State link to the right "Mexican and Canadian NAFTA Professional Worker."
Once you are approved for a TN visa you may apply for admission at a United States port-of-entry. If you are eligible following inspection by a CBP Officer, then you will be admitted as a TN nonimmigrant. Form I-94, Arrival/ Departure Record, will be evidence of your admission.