Big Changes for NOLs
NOLs will change carry back and carry forward aspects in 2018. TCJA also limits the amount of NOL that can be applied relative to other income.
Starting in 2018 NOLs can only be carried forward. There is no carry back. And, the taxpayer may only offset 80% of current income with the NOLs. The carry forward is forever.
Excess business losses are disallowed under TCJA and are instead carried forward as a NOL. For non-corporate taxpayers, an excess business loss is the excess of the aggregate of all the taxpayer’s trade or business deduction over gross revenues plus a threshold amount.  For 2018 the threshold is $250,000 ($500,000 for a joint return).