Basic question on K-1 MLP

@Canonical TT does not track your cost basis.  When you sell, you'll determine your cost basis yourself (using the information provided in the Sales Schedule that comes with your K-1) and enter that into the software.  All TT does is take the numbers you enter in Box 1, etc and move them to the appropriate forms, or put them into suspension for future years.

you may have a surprise when you sell.  selling an MLP is not the same as selling a stock. for that you know sales price and cost and hence gain or loss.  selling a partnership interest is actually the sale of the partnership's assets which can generate depreciation recapture that's reported on the sales schedule as 751 gain or gain subject to recapture as ordinary income (other wording might be used) so in these cases, your gain -  sales price less tax basis can consist of two parts capital gain and ordinary income (the 751 portion increases your tax basis reducing the capital gain). not all MLPs have this. it is reported to the IRS on line 20AB (2022 k-1) .  as you can imagine this is almost like selling rental property. the longer you hold it the more depreciation you take and hence the larger the 1250 gain. but for MLPs this depreciation recapture is ordinary income not taxed at the section 1250 preferred rate.   just a warning, but I got burned on one because I held it so long that the recapture greatly exceeded the suspended passive losses.