If you are a United States citizen (or a resident alien) and are married to a non-citizen, who cannot otherwise qualify as a resident alien under either the Substantial Presence Test or the Green Card Test (as explained at the IRS link directly below), then you have some options on how to file your US tax return, although current United States tax laws do not make this process particularly easy.
If your spouse can qualify as a resident alien, then the two of you together could file a normal Married Filing Joint income tax return (or the two of you could alternatively file as Marred Filing Separately). Basically, if your spouse can qualify as a resident alien, then your spouse is essentially treated as a regular US citizen for tax purposes.
It is also helpful to point out that you cannot file a tax return as Single, and ignore your spouse, regardless of residency status. (We mention that fact because we are sometimes asked.) Additionally, it is useful to know that the IRS considers those persons who are married as of December 31st of the year to have been married the whole entire year, for income tax purposes. That said, here are the (2) broad filing choices available to you.
Option # 1: You can file your US tax return as Married Filing Separately, and just report your own income there. If your spouse does not already have an ITIN number, or a Social Security Number, then this return would have to further be printed and paper filed. If your spouse has a valid ITIN or SSN, then the tax return would be eligible for e-filing.
If there is no ITIN or SSN, then in any place where the nonresident spouse’s taxpayer ID number is required on a tax form, you would take a black or blue pen and manually write “nonresident alien” or abbreviate as “NRA.” In some tax software programs, you can input any “made up” SSN or ITIN you want to, in order get through the program (we suggest 999-88-9999, 999-88-9998 or 999-88-9987, as those numbers should not produce any errors) as a temporary “placeholder.” You can then later “white out” that number when the paper pages are printed.
You can also claim a personal exemption for your spouse, if your spouse had no gross taxable income for U.S. tax purposes, and was not the dependent of another taxpayer. This mirrors the similar rule for US citizens and resident aliens filing as Married Filing Separately to claim the personal (dependency) exemption for their spouse, where that spouse has no taxable income, is not filing a separate tax return, and is not claimed as a dependent on any other taxpayer’s return. But, in order to do this and claim the personal exemption, your spouse must also have a valid Social Security Number or an ITIN.
Option # 2: You can elect to include your nonresident spouse on your US income tax return (which may be more or less tax favorable than Married Filing Separately); and file as Married Filing Jointly; but you would need to file a paper Form 1040 tax return in order to do so. The somewhat complicated process for completing this type of tax return is explained in detail at the IRS.gov website here:
Such a tax return (Option # 2) is probably best done by a professional tax preparer.
If you choose Option # 1 and have any difficultly with that, then having the tax return prepared by a professional is also an option.