My wife is doing her taxes and doesn't know how I fit in...

I came to the United States this year on a long cross-country trip, met my wife, and ended up marrying her. I am currently living in the country while we wait for my immigration papers to arrive. I do not work because I can't do that legally yet.

Does she claim me as a dependent? Is she "head of household" or "married filing jointly"?

I don't work in the US, but did work in my home country for 4 months in 2008 before my trip - do I have to claim my income from outside the US?

Thanks.

A spouse (which you are) is never a dependent.
You do not mention how long you have been in country but, putting that aside, you can elect (choose) to be treated as a US resident for tax purposes under section 6013(H) of the tax code.
Your wife now files as "married filing jointly". You can either exclude your foreign income with a Form 2555 or 2555EZ using the physical presence test or take the foreign tax credit with Form 1116.

If you have a social security number, she can claim you as a dependent, either head of household or married. If you received a W-2 or 1099 than you can claim your income as well. Go to IRS.gov website and they should be able to answer a lot of the questions you may have about it.

I'm sorry but a husband can never be a dependent simply because he fails the relationship test for dependents.

dienas67 is incorrect here.

Thanks Five Rings, I think it's getting more clear. So my wife will file "married, filing jointly." But I'm not sure I qualify for excluding my foreign income, as I am currently living in the United States, with no plans to stay here indefinitely. In answer to your question, I arrived in September of last year. And what I've read seems to suggest to exclude, I would have to still be residing in a foreign country?

My foreign income from 2008 is really small - I travelled and volunteered for much of the year and only worked for a few months. Of course I want to do everything correctly, but is there any sort of minimum amount you have to make before you need to claim?

Thanks again.

Sorry, "plans to stay," not "no plans"

If she is a U.S. citizen or resident, she can file joint return with you. Attach W7 (ITIN application) with your tax return.

Or she can file as married filing separately and claim exemption for you if you have $0 income in 2008.
Read Your U.S. Tax Return: Filing Status for Married (http://taxipay.blogspot.com/2008/02/filing-status-for-married.html)

The simplest approach for your wife is to file married filing separately without claiming an exemption for you. She simply puts "NRA" in where it asks for your social security number. Adding a minor level of complexity, she can also choose to claim an exemption for you if you have had no U.S. source income during 2008. However, you will need a U.S. tax ID for her to claim this exemption. For this, she would need to complete Form W-7 and attach it to her return in accordance with the instructions to Form W-7.

She cannot file as head of household if she has no children/dependents.

You can file married filing jointly, but you will need to include your worldwide income for 2008 on the U.S. tax return and complete Form W-7. You can claim foreign tax credits for foreign taxes paid. However, as the Texas Tax Expert has previously pointed out (https://www.askmehelpdesk.com/taxes/worldwide-income-proof-foreign-income-285149.html), you cannot claim the foreign earned income exclusion using the substantial presence test for pre-residency periods. I believe that you may, however, qualify for the bona fide residence test if a treaty applies. This approach, as you can see, is a bit more complex.

Thanks IntlTax, I'm glad to know there is a simple option.

Can you tell me if there's going to be a substantial difference in the amount of her tax return, depending on which option we go with? If not I am inclined to go with your first suggestion of married filing separately, and listing me as nra. If we do this, do I have to file my own tax return? I have no US source income from 2008 (or ever, for that matter). I haven't been working since entering in early September 2008.

I'm still quite lost re. your last paragraph. So foreign earned income exclusion is out because I did not live in my home country for 330 days in 2008, but I can claim foreign tax credits for the taxes I paid in Canada? Or do I qualify under the bona fide residence test? I lived in Canada from birth until the beginning of September 2008... But my home base is now with my wife in the US and I don't have any real "home" ties to Canada beyond my family and one bank account.

Really, I just want to do the simplest, most economical choice.

In addition - looking at the W7 I noticed it says "do not submit this form if you have or are eligible to obtain a USSN."
I am in the process of getting applying for a green card, so am I even allowed to file a W7?

Well think about this alternative.
Your wife files for an extension that allows her to file as late as Oct 15th of 2009.
http://www.irs.gov/pub/irs-pdf/f4868.pdf

By that time you should have your SS number right?

She figures her tax married filig separately and as if she were taking an exemption for you and pays that tax when she files the exemption.

When you get your SS number she completes the 1040 and files it... or

Your wife files the extension and then you guys file married filing jointly after you get your number and you do a simple 1116 to take a credit for your Canadian tax on your foreign income. Consider investing in a professional preparer just this once.