The K-1 you received reflects your share of the current year ordinary income/loss and separately stated items. Use these items to compute the basis in your stock as of the date you sold them.
The sale of the stock would go on Sch D, along with any other capital asset sales. The proceeds would be the selling price, and the basis would be your computed basis after taking into account all the items that increase/decrease the basis of the stock during the time frame you owned the stock.
The difference between sale price and adjusted basis would be the gain/loss and depending on the holding period, long or short term gain.
https://www.irs.gov/pub/irs-pdf/i1040sd.pdf
**Disclaimer: Effort has been made to offer correct information; but due to the discussion forum limitations, the poster disclaims any legal responsibility for the accuracy of the poster's response**
