In preparing a form 1065 K-1 the company has many options in presentation of the amounts reflected in Section L or your K-1. Your facts indicate that "tax basis" is checked.
Your tax basis and capital account are two entirely different items. As a partner in a partnership you need to track your basis in the partnership interest. This determines whether a partner has basis to take losses, whether distributions are taxable or not and also provides the information in determining your overall gain or loss upon disposition.
Appears you have not tracked your basis. However, since the K-1 indicates that it is prepared on a tax basis, you could use this amount as it should tie to any records that you should have been maintaining.
Now if you use this, it becomes tricky as it is important to understand whether any amounts reflected on the distributions line include any liquidating distributions. So in conclusion, you have your tax basis on your K-1 which is necessary to determine your final gain or loss.
*A reminder that posts in a forum such as this do not constitute tax advice.
Also keep in mind the date of replies, as tax law changes.
