Hello, Unit Petroleum!

I'm not sure what you mean by "in the exchange of the stock for warrants, the basis does not include the $36k of disallowed wash sales." The taxpayer's basis is the taxpayer's basis, and there's no special rule for receiving warrants in the bankruptcy process.

I assume you've read Unit's opinons here: http://www.unitcorp.com/pdf/Tax-Treatment-for-Cancelled-Stock-and-New-Warrants.pdf and http://www.unitcorp.com/pdf/FAQUnitCorporationNewEquitandWarrants20.pdf

You get Lacerte to recognize the losses by entering a transaction that shows the number of shares cancelled in bankruptcy, the date of purchase and date of cancellation (9/3/2020) and the actual adjusted basis of those shares. If you have a 1099-B reporting a covered transaction with erroneous basis, enter the 1099-B amount in the basis field, then make an additional entry in the field called "Adjustment to basis if reported incorrectly on Form 1099-B, Box 1e" in the Schedule D section of the Dispositions screen.