Readmission with a valid Form I-94: A Canadian TN may be readmitted to the United States for the remainder of the period authorized on Form I-94, without having to present TN supporting documents (employer letter and credentials) and without paying the $50 fee, provided that the original intended professional activities and employer(s) have not changed. If the original Form I-94 has been lost, the TN would have to present alternate evidence (e.g., the prior fee receipt and a letter from the employer) to be readmitted and reissued a Form I-94 under this provision. However, while Form I-94 and proof of Canadian citizenship should be the only documents necessary for readmission after a temporary absence, ISSS recommends that TNs carry a copy of the employer support letter and credentials just to be safe.

Canadian TN professionals may be eligible to participate in the NEXUS program, which is designed to expedite the entry into the U.S. and Canada of frequent business travelers.

Readmission with a valid Form I-94: Mexican TNs can also be readmitted to the United States for the remainder of the period authorized on Form I-94, without having to present TN supporting documents (employer letter and credentials), provided that the original intended professional activities and employer(s) have not changed. In addition, Mexican TNs must be sure to have a valid TN visa to reenter the United States.  Although Form I-94 and a Mexican passport with a valid TN visa should be the only documents necessary for readmission after a temporary absence, ISSS recommends that you carry a copy of the employer support letter and credentials. Mexican TNs are currently not eligible for the NEXUS program.

Readmission without a valid Form I-94: A Mexican TN whose period of admission has not expired, but who is not in possession of a valid, unexpired Form I-94, can be issued a new multiple-entry Form I-94 and be readmitted for the remainder of the authorized period of stay by presenting "alternate evidence" of his or her TN status.

Travel outside of the U.S. while a change of nonimmigrant status is pending with USCIS is considered to be an abandonment of the application.

Travel outside the U.S. while an extension of stay (on Form I-129) is pending with USCIS is not considered an abandonment of the application, but does present practical documentation difficulties. The regulations provide as follows:

The beneficiary must be physically present in the United States at the time of the filing of the extension of stay. If the alien is required to leave the United States for any reason while the extension request is pending, the petitioner, in the case of a Mexican citizen TN beneficiary, may request the director to cable notification of approval to the consular office abroad where the Mexican TN beneficiary will apply for a visa. In the case of a Canadian TN beneficiary, the petitioner may request the director to cable notification of approval of the application to the port-of-entry where the Canadian TN beneficiary will apply for admission to the United States. If approved, an extension of stay may be authorized for up to one year. There is no specific limit on the total period of time an alien may remain in TN status.

Long Service Center processing times might mean that an extension application will not be approved before the TN has to return to the United States. The implication of the wording of the regulation cited above is that if the original TN I-94 expires while the TN is abroad, he or she may have to remain outside the U.S. until the TN extension petition is approved. While the TN may reapply for a new TN admission at the border or airport by presenting the same documentation that must be presented for an initial TN entry, it has been reported that CBP officials may want the pending extension petition withdrawn before they will process an application for a new TN application for admission at the border.

In cases where an extension petition has not been filed, and "the expiration date of the previous period of admission" has not yet been reached, a Canadian TN could apply for a new admission at the border, by presenting a new employer letter and the same documentation that must be presented for an initial TN entry. Mexican TNs can do the same, but would also have to present a valid TN visa for readmission. The regulation reads as follows:

(2) Readmission at the border. Nothing in paragraph (h)(1) of this section shall preclude a citizen of Canada or Mexico who has previously been admitted to the United States in TN status, and who has not violated such status while in the United States, from applying at a DHS-designated port-of-entry, prior to the expiration date of the previous period of admission, for a new three-year period of admission. The application for a new period of admission must be supported by a new letter from the United States employer or the foreign employer, in the case of a citizen of Canada who is providing prearranged services to a United States entity, which meets the requirements of paragraph (d) of this section, together with the appropriate filing fee as noted in 8 CFR 103.7(b)(1). Citizens of Mexico must present a valid passport and a valid, unexpired TN nonimmigrant visa when applying for readmission, as outlined in paragraph (d)(1) of this section.