Short answer
A TN holder who is already in the United States can have their stay extended without leaving: the employer files Form I-129 with USCIS asking for an extension of TN status, in increments of up to three years. The filing includes the form and fee, a letter from the employer describing the continuing employment, and evidence that the worker’s credentials and licences remain valid. The other route to a new TN period is a fresh application at a port of entry or preclearance. This page covers the I-129 route only, from USCIS sources.
Who files — the employer, not the worker
Form I-129, Petition for a Nonimmigrant Worker, is filed by the employer (or the employer’s attorney or agent). Both Canadian and Mexican citizens can be granted extensions of stay in TN status in increments of up to three years, and there is no limit to the number of times TN status can be extended, provided the stay remains temporary (USCIS Policy Manual, Volume 2, Part P, Chapter 4). An extension keeps the same employer: a new employer means a new TN, covered in the changing employers guide.
The petition has to reach USCIS before the current period of stay ends. USCIS’s extension guidance and the form instructions govern the filing window and the address; both are on the I-129 page linked in the sources.
What the filing includes
- Form I-129 with the TN classification requested, signed by the employer.
- The filing fee. USCIS’s fee schedule lists the TN I-129 fee at $1,015 for a paper filing and $965 online, with a reduced $510 fee for small employers (25 or fewer full-time equivalent employees in the United States, including affiliates and subsidiaries) and nonprofits, plus the Asylum Program Fee that USCIS charges on Form I-129: $600, or $300 for small employers and $0 for nonprofits (USCIS Form G-1055 fee schedule). The TN visa cost guide lists every fee in one table.
- A letter from the employer describing the continuing employment — the USCIS Policy Manual (Volume 2, Part P, Chapter 4) describes the extension evidence as a letter describing the continuing employment, with evidence of continued valid licensing where the profession or the state requires it.
- Credential evidence — the degree, diploma or licence the TN list names for the profession, as in the original application.
- A copy of the current I-94, showing the TN admission the petition extends.
Use the current form edition: USCIS accepts only the 09/09/26 edition of Form I-129 for filings postmarked on or after November 9, 2026 (USCIS, Form I-129 page, linked in the sources).
An approval extends your stay — it is not a visa
An approved I-129 extends the period you may remain in the United States in TN status, and USCIS issues an approval notice with a new I-94 record for the extended stay. It does not print or renew a visa. Travel is separate: leaving and coming back means a new admission decision at the port of entry, and a Mexican citizen needs a valid TN visa to be admitted in TN status again, while a Canadian is visa-exempt and presents the application materials at the port of entry.
The alternative: a fresh application at the border
The same new TN period can also be requested in person: a Canadian presents a new packet at a port of entry or preclearance and is decided on the spot; a Mexican applies at a U.S. consulate for a new TN visa. The TNPath TN renewal guide walks through both routes — timing, documents and what a fresh application contains. The two routes differ in where the decision is made and what it costs in government fees; neither is described here as the better choice, because that depends on the traveller’s situation, not on the forms.
Common questions
Who files a Form I-129 TN extension?
Your employer. Form I-129 is a petition filed by the U.S. employer (or its attorney or agent) — the TN worker does not file it for themselves, though the worker supplies the credential evidence and the facts for the employer’s letter.
How long can a TN extension be granted for?
Up to three years at a time — the same maximum as an original admission — and there is no limit on the number of extensions, as long as the stay remains temporary.
Can I keep working while the extension is pending?
If the extension was filed before your current period ended, for the same employer, your employment authorization continues for up to 240 days while USCIS decides. The TN visa processing time guide works through the 240-day rule.
Does an approved extension renew my visa?
No. An approval extends your stay inside the United States; it does not extend a visa. A Mexican citizen who travels and returns needs a valid TN visa to be admitted in TN status again; a Canadian is visa-exempt and presents the TN application at the port of entry.
Will TNPath tell me whether I qualify?
No. TNPath is a document-assembly tool. It organizes the facts you provide into templates and gives general information. It doesn’t make eligibility determinations or recommend case-specific strategy. Only the U.S. government decides: U.S. Customs and Border Protection at the border or preclearance, and for Mexican citizens a consular officer decides the visa first.
Sources
- USCIS: I-129, Petition for a Nonimmigrant Worker (form, instructions and edition dates)
- USCIS Policy Manual, Volume 2, Part P, Chapter 4: Extension of Stay and Change of Status
- USCIS: TN USMCA Professionals
- USCIS: Form G-1055 fee schedule (Form I-129 TN fees)
- USCIS: How do I request premium processing?
Last reviewed October 31, 2026. General information, not legal advice. Rules and fees change; confirm with official sources before you travel.
See also: TN renewal and TN processing time: the 3 routes compared.