how do i compare last years state tax return to this year - line by line

Print them out and put them next to each other.

You will have to print both of them out.

You will have to pay the TurboTax fees to get the current return.

If you used TurboTax last year you can get a previous year tax return:

• Sign in to your TurboTax account. 
• Make sure you're using the same TurboTax account (same user ID) as in previous years.

There are two ways to get your prior-year returns:

1. Select Documents from the menu, 
2. Choose the tax year you want, and 
3. select Download tax PDF.

The second way is:

1. On Tax home, 
2. scroll down and select Your tax returns & documents. 
3. Select the year you want and select Download/print return (PDF).