TN NAFTA Professional

You must be a Canadian or Mexican citizen coming to the U.S. to work as a professional in one of the designated professions under NAFTA—including lawyers, scientists, accountants, teachers, engineers, and pharmacists; and the position must require a NAFTA employee.
Mexican nationals require a visa and must apply with the U.S. Embassy; however, Canadians do not need a visa and will only be required to produce supporting documents at the port of entry. The initial period of stay is three years and can be extended.

Spouses and unmarried children (under 21years of age) receive TD visas. They are not allowed to work but may study.