Filing Status: Married Filing Jointly vs Separately

First, congratulations.

Second, what country?

Third, the answer below is generally true, but might be modified if there is a tax treaty with your specific country.  @pk12_2 will be the best person to answer that. 

The general rule is that if you file separately, you only report your own income and deductions.  You usually can't e-file because your spouse doesn't have a tax ID number.

If you file jointly, you must make an election to treat your non-resident alien spouse as a US resident for tax purposes.  When you do this, you are required to list all your spouse's income and deduction on your tax return with your own income. This subjects your spouse's income to US taxation, but you can claim a credit or deduction if she also pays tax in her home country.  Filing jointly usually results in lower US tax because it has a lower tax rates, and some deductions and credits are limited or disallowed when filing separately.  However, the financial impact of filing jointly or separately in your situation can only be determined by you, by testing both scenarios.   IRS info here.

https://www.irs.gov/individuals/international-taxpayers/nonresident-spouse

If you want to file jointly, you will need to apply for an ITIN for your spouse.  You can't e-file your tax return.  Instead, print and sign the tax return, and also complete a sign a form W-7 ITIN application.  Mail the tax return, the W-7, and any required identity documents to the IRS address for ITINs, not the address for tax returns.  After the IRS issues the ITIN they will process your return.  Your wife will not be granted an ITIN unless she has a financial connection to the US -- since she does not have a US job or own property, her connection is established by filing a joint return, so she will generally be ineligible for an ITIN if you try to apply before filing the tax return.

Also note that when she applies for citizenship or a green card, there will be a question, "have you ever failed to pay income tax that you owed." She doesn't owe tax if you file separately, unless she somehow has US-source income, but she would owe tax if you filed jointly, so be sure to include her income on a joint return even though she doesn't get a US W-2 or 1099.

This TurboTax help article details your filing options when your spouse is a non-resident alien:

How should I file my taxes if my spouse is a nonresident alien? (intuit.com)

@please_help ,  Having gone through your post ( description of the situation ),  and agreeing with the  responses  from my colleagues @Opus 17  and @TomD8 ,  there are few things  I would like to add:

(a) You have not answered as to  your own immigration status ( citizen/ GreenCard/ Resident for Tax purposes ); if you are US citizen, then which country are you a citizen of  --- this is only for completeness and may have no effect on  tax situation

(b) Your spouse , where is she from ?    Has she ever been to the USA and if so when.  This may affect things because of tax treaty ( if any )

(c) Generally,  if the NRA spouse is not in the USA and your tax home is US, then the  "treating of spouse as a resident "   is  not much benefit, especially if there is no  tax treaty in effect  ( because then you cannot get credit for the foreign taxes paid nor be eligible for Foreign Earned Income Exclusion ).

(d)  Note that when filing a US tax return jointly with your spouse , it is total household  income that is considered for  threshold of filing requirement.

 Please answer the questions   and I will circle back once I hear from you --yes ?

pk

Greetings, TurboTax Community. I appreciate your feedback, Opus 17, TomD8, and pk!

I am an American citizen. I return to Manila in two weeks to conduct an in-person Catholic wedding ceremony to remove all reservations of my love for my foreign wife. This will be my second visit to the Philippines, my wife's homeland.

I remain undecided how to file - either "Married, Filing Separately" or "Married, Filing Jointly." While the former is the 'status quo' allowing for e-File, the latter slightly reduces my taxable income (I will remain at 12% in both scenarios). No matter which is chosen, the economic data will be nearly exclusively my own (my wife has worked as an undocumented live-in caretaker her entire life with no tax reporting requirements due to her income being egregiously low). When I die, as my beneficiary, my wife will then have cause to file a tax return in her name; if all that is needed to file is an ITIN, then perhaps now is the time to apply for her ITIN while accepting that I must mail all federal and state income tax returns from this point forward?