I lived in MS for 9 months and TN for 3 months. I worked in TN all 12 months.
While filling out MS State return the 1099-INT has 4 boxes
1) MS Withholding
2) MS State Income
3) Other State Name
4) Other State Income
I know for box 1 & 2 I calculate how much interest income I earned during the 3 months I lived in MS, but I don't understand boxes 3 & 4. Am I supposed to calculate how much interest income I earned while living in TN? Why would MS care how much interest I earned in TN? Would it just be Total Interest Income - Mississippi Interest Income?
Yes. Calculate how much interest you earned while living in Tennessee. The boxes may have no impact on the Mississippi return at all. If the state in question did have income tax, then there could have been a credit perhaps for Mississippi.
Tennesse has a Hall Income Tax who earned taxable interest and dividends that exceeded $1,250 ($2,500 if married filing jointly) during the tax year.
TurboTax will let you know whether you need to do anything further for Tennessee. In case you may need this for your future reference, this is the Tennessee Dearpatment of Revenue site.