I think I'm better filing MFJ,on Federal return but what concerns me is I was told I have to file my MI. state return using our combined income when my spouse doesn't have a state income tax nor works in MI. can't I just file my own state income tax return without my spouses income added ? I owe state taxes cause our incomes are combined and I'm the only one that had state taxes taken out Tn don't have state tax. By the way TN has a adjust salet tax deduction can I use that on federal ?

Well, Tennessee is NOT a reciprocal state with Michigan, so you cannot work out of it that way.

Many states require that when you file jointly, all income on the joint return is considered to be earned in that state (whether it is or not), and you get relieve by claiming a tax credit for the taxes paid to the state where the non-resident spouse is working, but since Tennessee has no income tax, that will not work for you.

Since Michigan MANDATES that, if you file a joint return, you MUST file a joint state return, the best alternative is probably to file a Married Filing Separate federal return. You would then be allowed to file a Married Filing Separate Michigan return with ONLY your Michigan income. That is probably your best option tax-wise.