What are you supposed to fill out on the Check This Entry Form 80-160? I'm not sure what is supposed to go here or why. It's for MS but I'm filing taxes for MS and LA.

It depends. Mississippi Form 80-160 is used to split your income between Mississippi and other states, in your case Louisiana.

The form is used to make sure that Mississippi will tax any other income by at least Mississippi rates. These are calculated based on percentages. 

It is important when filing more than one state that the state where you live on December 31 is entered last.

• If you did enter where you lived on December 31 last, then I recommend going back to any Forms W-2 that were entered and making sure the state details are correct. Then. go over the states.
• If you started with where you live now, I recommend deleting and re-adding the states so that the income is split correctly.
  • If you do need to delete and re-add the states, follow these steps: 
    • From the left menu select State>
    • Continue>next to your state, click the Trash Can icon and follow through the rest of the questions ending with Done
    • Click Add Another State>Your state>and go through the interview again.

Click the links below for more details:

How do I file a nonresident state return?

How do I file a part-year state return?

2019 Louisiana Part-Year and Nonresident Income Tax Instructions

2019 Mississippi Part-Year and Nonresident Income Tax Instructions

@joshuaradams35