Donated, publicly traded partnerships – in particular master limited partnerships (MLPs) – are an important exception to the typical fair market value deduction for long-term gain securities, as the charitable deduction must be reduced by the amount of ordinary income that would have been realized if the property had been sold at fair market value on the date contributed. For MLPs with substantial accumulated depreciation, this can greatly reduce the charitable deduction. Additionally, if the partnership carries debt (often the case with MLPs), the donor may be liable for taxes if the contribution is treated as a “bargain sale.”
IRS PUB 526 ordinary income property starting at page 11
IRS PUB 544 sale of assets including bargainsales
https://www.irs.gov/pub/irs-pdf/p544.pdf
https://www.irs.gov/pub/irs-pdf/p526.pdf
basis comp worksheet
https://tax.thomsonreuters.com/content/dam/ewp-m/documents/tax/en/pdf/other/quickfinder-updates/qpep...
the numbers entered are an example - ignore them
your purchase price (starting basis) is reduced by the cumulative losses and expenses reported (regardless of whether suspended or not due to MLP passive loss rules) and also by distributions and increased by your share of nonrecourse liabilities = adjusted basis
you could have a bargain sale because the FMV (the price you could sell it for) is less than your adjusted basis.
