K1 disposition and 1099-b, double reporting. Had undistributed 1256 income on k1 each year of ownership, which is not accounted in cost basis on 1099-B.

[bezdecor]

 I have received a final K1 after selling an exchange traded fund. Each year of ownership I received a K1 and the profits in the fund were taxed, but the profits were suppose to offset the cost basis. Now I have a k1 with proper adjusted cost basis. But this sale was also reported to me on 1099-B from broker without cost basis adjustment. Do I remove that sale from my 1099 and  adjust my long term gains reported by broker? Or do I enter adjusted cost basis on 1099 instead and report 0 in cost and sale price in k1? Or do I report the properly adjusted cost and sale basis on K1 and remove from 1099?

[maglib]

When you fill out the 1099-B make the cost and the proceeds the same and state in the description K-1 reported XYZ partnership, this way the IRS knows you reported the proceeds. The k-1 entry will appropriately report the gain/loss.