how import both previous year's returns into married-filing-jointly return ?

[RustyShackleford]

I just got married.  For 2018, we want to try filing a married-filing-jointly return for the first time (because it is probably best for us, plus we can use TurboTax's "what-if" tool to check if filing separately would be better).  This is Premier version of desktop product.

When I started the joint return, it asked if I wanted to import my last year's return and I did.   But I can't figure out how to now import my wife's return.

[Carl]

It is physically impossible to import from more than one prior year return. Doesn't matter if you use the online version or the CD version of TurboTax.

For a married couple to file separate returns will almost *always* cost you more tax-wise. When a married couple files separate, they *automatically* disqualify themselves for deductions and credits they would otherwise qualify for if they filed joint. The exceptions are so rare, I won't bother listing them here, as if one of the exceptions did apply to you, you'd be paying someone else to do your taxes (because you'd be that rich) and not wasting your time doing them yourselves.

For the first year of marriage it is generally best that you not import from either tax return. Instead, you should print out each prior year return so that you can manually enter any "carryover" information into the new, first joint return and start your married tax life with a "fresh start) so to speak.

[RustyShackleford]

Ok, thanks for the clarification on not being to import both our previous returns.

Not the right place to discuss MFJ vs. MFS I guess, but I'd argue that MFS being better isn't that rare.   Suppose one of us can exceed the standard deduction, but together we don't ?    Suppose her much higher AGI (I am retired, she is well-paid) kicks us both into IRMAA (higher Medicare premium for high-earners) but separately only she is IRMAA ?

[Carl]

Suppose one of us can exceed the standard deduction, but together we don't

Yep, the IRS already has that loophole closed. IRS Publication 501 at https://www.irs.gov/pub/irs-pdf/p501.pdf on page 24 under "Persons not eligible for the standard deduction". Reads as follows:

Your filing status is married filing separately, and your spouse itemizes deductions on his or her return,

Basically, when a married couple files separate, then if one itemizes they must both itemized - even if the itemized deductions of one of you is ZERO.   Likewise, if one of you takes the standard deduction, then you must both take the standard deduction regardless of the amount of your itemized deductions.

Other things you lose out on when a married couple files MFJ are;

You can not take the EIC,
You can not take the credit for Child and Dependent Care, in most cases,
You can not take the Education credits/deductions, and there are many other restrictions.
 If either of you receive Social Security benefits and you live with your spouse, more of the SS benefit will be taxable, and the person receiving it will have to include the SS benefit in their gross income when determining whether they have to file.

[RustyShackleford]

Yikes, ok, thanks for the free tax advice.   Looks like for us, IRMAA may be the only possible advantage of MFS.   None of the stuff on the list of disadvantages applies to us, although the SS taxation will pretty soon.