You're correct. This is very uncommon, but you should be asked about it in the state tax questions for Montana. You would not enter this in the federal taxes area, only within your state will the questions be asked. As there can be numerous items to account for in each state, be sure to read through each screen. Let me know if you've gone through your state tax questions yet or not and how it goes. If you're not asked about it, you can always calculate the amount and enter it as an 'addition to federal adjusted gross income'. All of the state tax sections give you the option to enter any 'additions' and 'subtractions.'
