Article: Mexican citizens must have a TN visa to enter the US and therefore, must apply at a US Consulate or Embassy abroad.  It is recommended that Mexican citizens apply in Mexico since officers in those consulates are more aware of the TN visa regulations and procedures. Appointments can be made online through the department of state website or by phone.  To be issued an appointment, complete and submit Form DS-160 online.  The application fee is $190 and can be paid online.

What is a summary?
Make an appointment with a US Consulate or Embassy. Pay the application fee and complete the application form.