In general, resident aliens are taxed just like U.S. citizens. You would list a resident-alien spouse on your return and provide his or her Social Security number (SSN). If your spouse is not eligible for a Social Security number, they will need to apply for an Individual Taxpayer Identification Number (ITIN) from the IRS.

If your spouse is a nonresident alien, you can treat your spouse as a resident alien for tax purposes. If you choose this option, you can file a joint tax return with your spouse and have an increased Standard Deduction, but you will have to include his/her world wide income