some useful web site and summary:

http://travel.state.gov/visa/temp/types/types_1274.html

Professionals of Canada or Mexico may work in the U.S. under the following conditions:

• Applicant is a citizen of Canada or Mexico;
• Profession is on the NAFTA list;
• Position in the U.S. requires a NAFTA professional;
• Mexican or Canadian applicant is to work in a prearranged full-time or part-time job, for a U.S. employer (see documentation required). Self employment is not permitted; ???
• Professional Canadian or Mexican citizen has the qualifications of the profession
  

A Canadian citizen without a TN visa can apply at a U.S. port of entry with all of the following:

• Request for admission under TN status to Department of Homeland Security, Customs and Border Protection, U.S. immigration officer;
• Employment Letter - Evidence of professional employment. See Employment Letter below;
• Proof of professional qualifications, such as transcripts of grades, licenses, certificates, degrees, and/or records of previous employment;
• Proof of ability to meet applicable license requirements;
• Proof of Canadian citizenship- Canadian citizens may present a passport, as visas are not required, or they may provide secondary evidence, such as a birth certificate. However, Canadian citizens traveling to the United States from outside the Western Hemisphere are required to present a valid passport at the port-of-entry;
• Fee of U.S. $50 ;
  

Additionally, as nonimmigrants, applicants must demonstrate that:
That their stay is a temporary period that has a reasonable, finite end that does not equate to permanent residence.

Employment Letter

The employer in the U.S. must provide to the applicant a Letter of Employment in the United States. The letter must indicate that the position in question in the U.S. requires the employment of a person in a professional capacity, consistent with the NAFTA Chapter 16, Annex 1603, Appendix 1603.d.1.

The applicant must present evidence of professional employment to satisfy the Consular Officer of your plans to be employed in prearranged business activities for a U.S. employer(s) or entity(ies) at a professional level. Part-time employment is permitted. Self-employment is not permitted. An employment letter or contract providing a detailed description of the business activities may be provided from the U.S. or foreign employer, and should state the following:

• Activity in which the applicant shall be engaged;
• Purpose of entry;
• Anticipated length of stay;
• Educational qualifications or appropriate credentials demonstrating professional status;
• Evidence of compliance with DHS regulations, and/or state laws; and
• Arrangements for pay.
• Although not required, proof of licensure to practice a given profession in the United States may be offered along with a job offer letter, or other documentation in support of a TN visa application.
  
  

Additional Documentation or Qualifying Requirements

Additionally, applicants must demonstrate that they are properly classifiable as NAFTA Professional for TN visa, under U.S. law by:

• Education Requirement- The applicant's employer must submit proof that the applicant meets the minimum education requirements or has the alternative credentials set forth in NAFTA agreement, chapter 16 appendix 1603.d.1. Evidence of professional qualifications may be in the form of degrees, certificates, diplomas, professional licenses, or membership in a professional organization. Degrees, diplomas, or certificates received from an educational institution outside the United States, Canada, or Mexico must be accompanied by an evaluation by a reliable credentials evaluation service specializing in evaluating foreign documentation.
• Work Experience Requirement - Document proving to the applicant's experience should be in the form of letters from former employers. If the applicant was self-employed, business records should be submitted proving that self-employment.
  
  

Spouses and children (unmarried children under the age of 21) who are accompanying or following to join NAFTA Professionals (TN visa holders) may receive a derivative TD visa. Applicants must demonstrate a bona fide spousal or parent-child relationship to the principal TN visa holder. Dependents do not have to be citizens of Mexico or Canada. Spouses and children cannot work while in the U.S. They are permitted to study.

How Long Can I Stay?

The maximum period of admission into the U.S is one year. The US Citizenship and Immigration Services (USCIS) grants extensions of stay in time amounts of one year. There is no limit on the number of years a TN visa holder can stay in the United States. However, the TN visa status is not for permanent residence.

Extension of Stay

For Canadian or Mexican citizens admitted as a NAFTA Professional may seek an extension of stay, which may be granted up to one year, by:

• If the applicant is in the U.S., employer may file Form I-129 Petition for Non-immigrant Worker with the US Citizenship and Immigration Services’ (USCIS) Nebraska Service Center.; or
• Applicant may apply at a port of entry using the same application and documentation procedures above as required for the initial entry.

How Do I Get More Information on the TN Visa?

Further information on the NAFTA, including the “NAFTA Handbook,” go to the Department of Homeland Security, USCIS Website, select North American Trade Agreement.

Canadian citizens can find more specific information regarding TN visas through Embassy Ottawa's website.

About the NAFTA Professional Job Series List

For a complete list of professions with minimum education requirements and alternative credentials, see NAFTA's website. With some exceptions, each profession requires a baccalaureate degree as an entry-level requirement. If a baccalaureate is required, experience cannot be substituted for that degree. In some professions, alternative criteria to a bachelor's degree is listed. For some professions, experience is required in addition to the degree.

Additional Information

• No assurances regarding the issuance of visas can be given in advance. Therefore final travel plans or the purchase of nonrefundable tickets should not be made until a visa has been issued.
• Unless previously canceled, a visa is valid until its expiration date. Therefore, if the traveler has a valid U.S. visitor visa in an expired passport, do not remove the visa page from the expired passport. You may use it along with a new valid passport for travel and admission to the United States.

Entering the U.S. - Port of Entry

Applicants should be aware that a visa does not guarantee entry into the United States. The visa allows a foreign citizen to travel to a port-of-entry in the United States, such as an international airport, a seaport or a land border crossing, and request permission to enter the U.S. The Department of Homeland Security, Customs and Border Protection, U.S. immigration inspector will permit or deny admission to the United States, and determine your length of stay in the U.S., on any particular visit. Form I-94, Record of Arrival-Departure, which notes the length of stay permitted, is validated by the immigration official. Form I-94, which documents your authorized stay in the U.S., is very important to keep in your passport. Additionally, as a Mexican citizen seeking entry as a NAFTA professional, you must present evidence of professional employment to satisfy the Immigration Officer of your plans to be employed in prearranged business activities for a U.S. employer(s) or entity(ies) at a professional level. To find out more detailed information about admissions and entry in the U.S., select Admissions to go to the Department of Homeland Security, Bureau of Customs and Border Protection Internet site.

Staying Beyond Your Authorized Stay in the U.S. and Being Out of Status

• You should carefully consider the dates of your authorized stay and make sure you are following the procedures under U.S. immigration laws. It is important that you depart the U.S. on or before the last day you are authorized to be in the U.S. on any given trip, based on the specified end date on your Arrival-Departure Record, Form I-94. Failure to depart the U.S. will cause you to be out-of-status.
• Staying beyond the period of time authorized by the Department of Homeland Security (DHS) and being out-of-status in the United States is a violation of U.S. immigration laws, and may cause you to be ineligible for a visa in the future for return travel to the U.S. Select Classes of Aliens Ineligible to Receive Visas to learn more.
• Staying unlawfully in the United States beyond the date Customs and Border Protection (CBP) officials have authorized, even by one day, results in your visa being automatically voided, in accordance with INA 222(g). Under this provision of immigration law, if you overstay on your nonimmigrant authorized stay in the U.S. your visa will be automatically voided. In this situation, you are required to reapply for a new nonimmigrant visa, generally in your country of nationality.
• For nonimmigrants in the U.S. who have an Arrival-Departure Record, Form I-94 with the CBP admitting officer endorsement of Duration of Status or D/S, but who are no longer performing the same function in the U.S. that they were originally admitted to perform (e.g. you are no longer working for the same employer or you are no longer attending the same school), a DHS or an immigration judge makes a finding of status violation, resulting in the termination of the period of authorized stay.

Further Visa Inquiries

• Questions on visa application procedures and visa ineligibilities should be made to the American consular office abroad by the applicant. Before submitting your inquiry, we request that you carefully review this web site and also the Embassy Consular web site abroad. Very often you will find the information you need.
• If your inquiry concerns a visa case in progress overseas, you should first contact the U.S. Embassy or Consulate handling your case for status information. Select U.S. Embassy or Consulate , and you can choose the Embassy or Consulate Internet site you need to contact.

Professionals