Individuals can make Net Operating Loss (NOL) carryback elections for Montana tax purposes on Form 2, Schedule VIII – Reporting of Special Transactions for the 2017 tax year.
You must check the box if you want to forgo the carryback of a 2017 NOL.
Special Carryback Periods – Farming, Casualty Losses (Including Fire), and Federally Declared Disaster Zones
If you do not forgo your carryback period, and you are allowed a carryback period of more than two years, you must check the appropriate box to use a special carryback period. Special carryback periods depend on the statutory provisions provided in IRC §172. For example, for the 2017 tax year, a three-year period is used for losses derived from casualty such as losses of property arising from fire. Farming losses can be carried back five years.