Hi,

I am a Canadian citizen married to a Japanese citizen (who lives and works in Japan), currently going to school in the US on an F1 visa. I've been on the F1 since Sept/07, living pretty much continuously in the US. School will finish in Jun/2010, and I expect to begin work in the U.S. in Sept/2010. I further expect to primarily be in the US between June and Sept/2010.

Subsequent to graduation, I will attempt to obtain either OPT or a TN visa.

Considering the 2010 tax year, I have the following questions:

1) if I choose OPT, I must still file as a NR.. right?
2) more importantly, if I choose TN, must I file as an NR, or may I file as a resident? What's the basis for the decision?

Concerning 2, I've already seen answers on this forum for this question with respect to H1B visas (i.e. must file as an NR); however, I haven't seen any explanation as to *why* one must file as an NR after switching from F1 to non-F1 (e.g. substantial presence test? Other statutory language/regulation stating something like a test based on relative portion of the tax year spent on F1 and non-F1?)

Thanks.

1. Right
2. If you do not complete substantial presence test on TN visa, you have two choices:
Your U.S. Tax Return: Substantial Presence Test
a. File nonresident tax return and form 8843.
b. File joint return as residents. Attach W-7 (ITIN application) for your spouse with your tax return.

You can find an explanation for the Substantial Presence Test in IRS Pub 519, which can be downloaded from Internal Revenue Service.