A new  client just received a letter from the IRS for 2017.    It states that the tax preparer they had in 2017  did not elect to forego the 2017 net operating loss carryback period.   The passive loss they have is a result of years of un-allowed passive losses on a limited partnership K-1.   2017 was the final year of the K-1 which freed all these passive losses.   I don't have the K-1 yet, to find out what type of passive loss this is, ( ordinary, capital gain, 1231, 1250 etc.) not sure if that matters,  but is  there a type of passive loss that does not require it to be carried back.   The IRS is giving them 30 days to amend 2015, 2016 and 2017 tax returns to carryback this loss.    The passive losses were not allowed in prior years, so I am not sure how amending them will change any prior year return, but wanted to reach out to understand what I might be missing.

Any help is greatly appreciated.