One of the things I found was that I needed to fill in the drop down boxes with
(1) the amount not taxable in MA and
(2) the remainder amount of Exempt Dividends
For the first entry I picked Massachusetts. For the second entry (the remainder amount) I scrolled to the bottom of the "State" pick list and selected something like "multiple states"
TurboTax won't total the amounts column for you, but they must add up to the amount shown at the top of the page. If they don't, after you hit continue, the program will suggest that you revisit the page, which you can do by selecting "Back."
