Deductions & credits

So sorry for your loss.   Your mother can file using standard or itemized deductions---whichever is better for her if she files a joint return.  The fact that your step-father passed away has no bearing on that.   She can file a joint tax return for 2022, and use all of their itemized deductions if she wants to.   Whether the itemized deductions affect her refund or tax due will depend on whether the itemized deductions exceed the amount of the standard deduction.  

However, if for some reason she chooses to file as married filing separately for 2022, then she must go by the rule that says if one spouse uses itemized deductions, the other spouse must itemize too.  So her spouse's final return would have to be itemized---even if it is disadvantageous.  When a married couple files married filing separately, they each have to use their standard deduction, or each can itemize.  It cannot be one of each.  

You do not say why she may want to file separate returns.   Provide some details----did your step-father owe back taxes?  Child support?   Is there some reason she would want to avoid filing a joint return?

 For the year that your spouse died, you can still file a joint return.  That way, you will get the married filing jointly standard deduction of $25,900 (+ $1400 for each spouse 65 or older) which will lower the amount of income you are taxed on.

In My Info, you will need to indicate that your spouse died. When his name is in My Info,  there is a screen early in the interview that asks "Do any of these apply to [name] ?’” where you will do that, and then a drop down will appear where you can enter the date he passed.

If you have qualifying dependent children you will be able to file as a qualifying surviving spouse  (QSS) for the next two years after this tax return.  Post back if you need further help.

https://blog.turbotax.intuit.com/tax-planning-2/tax-implications-for-taxpayers-who-have-lost-a-spous...

deductions without considering the caps and thresholds that must be met?

STANDARD DEDUCTION

Many taxpayers are surprised because their itemized deductions are not having the same effect as they did on past tax returns.  The new higher standard deduction and the elimination of certain deductions, as well as the cap on state and local taxes have had a major impact since the new tax laws went into effect beginning with 2018 returns.

Your itemized deductions have to be more than your standard deduction before you will see a change in your tax owed or tax refund.  The deductions you enter do not necessarily count “dollar for dollar;” many of them are subject to meeting  tough thresholds—medical expenses, for example, must meet a threshold that is pretty hard to reach. (Only the amount that is MORE than 7.5% of your AGI counts)   The software program uses all the IRS rules that apply to the expenses you enter, and it tells you if you have enough to use your itemized deductions or if using the standard deduction is more advantageous for you.  Under the new tax laws, some deductions have been capped—there is a $10,000 limit to the itemized deductions for state, local, property and sales taxes.

Your standard deduction lowers your taxable income.  It is not a refund.  You will see your standard or itemized deduction amount on line 12 of your 2022 Form 1040.

2022 STANDARD DEDUCTION AMOUNTS

SINGLE $12,950  (65 or older + $1750)

MARRIED FILING SEPARATELY $12,950  (65 or older + $1750)

MARRIED FILING JOINTLY $25,900  (65 or older + $1400 per spouse)

HEAD OF HOUSEHOLD  $19,400  (65 or older +$1750)

Legally Blind + $1750