Most likely the gain/loss shown on the 1099-B is wrong because it does not take into account the activity that affects the PTP's tax basis. The broker does not receive the K-1, so it can not make this adjustment. What's worse is the broker figures wash sales based on what you paid when you bought it. However, if the PTP had losses that would reduce your basis, and instead of having a wash sale loss, for income tax purposes you could have a taxable gain. Further, that would make the tax basis of the shares that supposedly caused the wash to be wrong.
The reverse can happen if the activity produced an increase in tax basis. The broker would compare the original cost to the selling price, and if a gain, it would be reported as such. However, the basis increase would could result in a loss the broker did not know about and thus miss a wash sale.
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hope the following helps - total disposition only ( yo didn't own shares at year end and did not buy shares in 2026 that would cause a wash sale.
MLP and PTP reporting k-1 and 8949/1099-B
Enter the k-1 info
Check the PTP box
If total disposition then:
Check final K-1 (s/b marked on actual k-1)
Check sold or otherwise disposed of your entire interest
On the k-1 disposition section for sales price use the ordinary income. It would be reported in box 20AB of K-1 and a column on the sales schedule. Sometimes you’ll see a column with the “751” or the words “Gain subject to recapture as ordinary income” or similar wording on the sales schedule. No 20AB, no column on the sales schedule indicated as ordinary income, then there is no ordinary income. The following is for the k-1 sale section - not the 8949/schedule D
Sales Price = line 20AB (1065 k1) use 0 if box 20AB is missing or zero and no ordinary income column on the sales schedule
* Selling expenses = 0
* Basis = 0 (zero – nothing else)
* Gain is computed and should be the same as the sales price.
* Ordinary gain = enter the same amount as the sales price
* Other lines should be zero
This amount flows to form 4797 line 10 and is taxed as ordinary income. This step is necessary, so any suspended passive losses are now allowed assuming complete disposition.
Some do not understand the above. The 1099-B (capital gain/loss portion) reporting is not done in this section in Turbotax. Doing so will result in reporting the sale twice if you enter the 1099-B info.
Now for the 8949/1099-B Capital gain/loss reporting
The broker’s form is probably coded as B or E – sales proceeds but not cost basis reported to the IRS. This is because the broker does not track the tax basis. It used what you paid or was adjusted due to a merger or acquisition but does not reflect the k-1 activity.
The correct tax basis is (note that your sales schedule may have a column that reports the adjusted/average tax/cost basis excluding the ordinary income which must be added):
What’s on the sales schedule as purchase price/initial tax basis (usually column 4). it may differ from what you paid originally because of a merger or acquisition. Some of your original cost is allocated to the new security.
There is a column on the sales schedule that says cumulative adjustments to the basis. If it’s positive add it to the cost shown. If it’s negative subtract the amount.
Finally, add the amount of ordinary income reported above.
The result is your corrected cost/tax basis for form 8949 – the capital gain/loss portion.
Note that on some sales schedules, there may be a column with your adjusted basis already computed. To that add the ordinary income. Read the info provided at the top of the schedule about what the columns represent.
Some other things. Look at line 20AB. That number should be added to the ordinary income above for reporting the 199A (qualified business income from the PTP). You don’t have to enter this but then you lose out on a tax deduction = 20% of this amount
