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"Entering a net operating loss (NOL) for a year other than current tax year" is a helpful article.

You must do the calculation of the 80% limit and input it.

The disallowed portion goes away forever.

How to enter and calculate the qualified business income deduction, section 199A, in Lacerte

For QBI loss carryovers that are still limited by passive activity limitations: 

1. Open the business activity screen that is associated with the QBI Loss:
   • Screen 20.1 for Partnership K-1s
   • Screen 20.2 for S Corporation K-1s
   • Screen 20.3 for Estate and Trust K-1s
   • Screen 18 for Rental and Royalty Income
   • Screen 19 for Farm Income
2. From the Sections on the left choose Prior Year Unallowed Passive Losses.
3. Enter the carryover amounts in the correct field:
   • For Screen 20: 20YY QBI unallowed passive loss (where YY is the prior year).
   • For Screen 19: 20YY QBI Operating (where YY is the prior year)
   • For Screen 18: 20YY QBI Operating (where YY is the prior year)
   • For Screen 16: 20YY QBI Operating (where YY is the prior year)