My spouse is not an American citizen

If you are a U.S. citizen or resident alien, you have the option to have your nonresident spouse treated as a resident.  This includes situations in which one spouse is a nonresident alien at the beginning of the tax year, but a resident alien at the end of the year, and the other spouse is a nonresident alien at the end of the year.

A U.S. citizen or resident alien who does not make this choice will need to file using the status "Married Filing Separately" as described in IRS Publication 501 at this link.

To file your taxes you will need an ITIN for your wife.  For details on how to do this, click these links for Form W-7 and Instructions for Form W-7.

You treat your nonresident spouse as a resident for tax purposes by making the choice described in IRS Publication 519, U.S. Tax Guide for Aliens, designating your spouse as a resident in TurboTax, and attaching a required statement to your mailed (not-efiled) tax return.

Here is some of the Publication 519 text describing the option to treat your nonresident spouse as a U.S. resident for tax purposes:

"If, at the end of your tax year, you are married and one spouse is a U.S. citizen or a resident alien and the other spouse is a nonresident alien, you can choose to treat the nonresident spouse as a U.S. resident. This includes situations in which one spouse is a nonresident alien at the beginning of the tax year, but a resident alien at the end of the year, and the other spouse is a nonresident alien at the end of the year."

To make the choice, attach a statement, signed by both spouses, to your joint return for the first tax year for which the choice applies. It should contain the following information.

• A declaration that one spouse was a nonresident alien and the other spouse a U.S. citizen or resident alien on the last day of your tax year, and that you choose to be treated as U.S. residents for the entire tax year.
• The name, address, and identification number of each spouse. (If one spouse died, include the name and address of the person making the choice for the deceased spouse.)