MN State Tax when Spouse in TX

[amitsamal07]

Got married last year before Dec 31st, I live and work in MN so have MN state taxes but my Spouse lives in Texas.

When filling taxes for the federal that is easy but for state is where i am looking for some direction.
Texas has no state tax so great, but MN has state tax. Per our understanding if we do federal joint then we have to do MN state joint filing but then this takes our AGI and the tax owed goes up by $7500. 
So my question is when calculating the MN  state taxes should it be my income only or both our income?

[AmyC]

MN should be only the MN income. MN does not tax TX income. You will need to file MFJ to match the federal. While you have been a resident of MN throughout the year, your marriage has not. A part year return will allow you to separate out your income for correct taxation. 

[amitsamal07]

So when I file for MN State tax, I will just select resident status as part year and put the amount earned in MN only there. This drastically reduces my taxes owed to $300, but I am a bit confused because if I just file my taxes as Married filing separate it says for the same MN income I owe $102 but when I put MFJ this number is $307 after selecting Part Year Resident Status and providing the MN income only.

Why is this difference there?

[DMarkM1]

Difference is because on joint return MN uses all income, even from TX, to arrive at a percentage of MN taxable income divided by total taxable income.  Your tax is first figured as if a resident of MN all year.  The percentage is then multiplied by that resident tax to arrive at the part-year tax.   So as her income is added in, the total income goes up and that number is used to figure the MN tax as a resident.  Further, her income probably pushed you into a higher MN tax bracket. 

Here is a link with 2023 MN tax brackets for reference. 

It may be prudent to figure the overall (FED and MN total) tax using both filing statuses to see which is better for you.