Canadian citizen working in U.S. on TN visa not passing green card or substantial presence test. Should U.S. taxes be filed as resident alien or non-resident alien?

[Discovery]

I'm a Canadian citizen who moved to the U.S. in July for work on a TN visa. All major ties in Canada were severed at the time of the move. According to the information on the CRA website I would be considered a non-resident in Canada for tax purposes after the day of the move. So I would need to file taxes in Canada for the first portion of the year as a resident. According to the information on the IRS website I do not pass the green card or substantial presence test. So in the U.S. I would be considered a non-resident alien for tax purposes. However, there is a tax treaty between US and Canada which may have an effect on the determination of residency for tax purposes. My question is: in U.S. should I file taxes as a non-resident alien, or as a resident alien?

[KarenJ]

I do not think the treaty would affect your residency in the US for tax purposes.  If you have not passed the substantial presence test for 2018, you would be considered a nonresident of the US for 2018 tax purposes and will need to file a US nonresident return.

TurboTax does not support nonresident returns.

However we have a partnership with Sprintax offering a nonresident tax filing solution to our TurboTax customers.

Visit the TurboTax/Sprintax site for more info or to get started.

https://turbotax.intuit.ca/tips/using-the-united-states-canada-income-tax-treaty-to-reduce-double-ta...

You will be considered a United States resident for tax purposes if you meet the substantial presence test for the calendar year. To meet this test, you must be physically present in the United States (U.S.) on at least:

1. 31 days during the current year, and
2. 183 days during the 3-year period that includes the current year and the 2 years immediately before that, counting:

• All the days you were present in the current year, and
• 1/3 of the days you were present in the first year before the current year, and
• 1/6 of the days you were present in the second year before the current year.