how do i figure cost basis for form 1099-b

after leaving walmart i sold my stock, it was purchased over time as weekly payroll deduction. my 1099-b does not list a cost basis, how do i find it
    When you buy securities you are responsible for determining your basis in that security, so the short answer is that you find the basis from your own record of purchases.  Prior to 2011 nobody else but you was responsible for doing this.

    If you haven't maintained records of your purchase you have only 3 choices:

    1)See if Walmart will tell you what it is.  I expect they sent statements to you from time to time about your basis so they might respond "you already have this information," but they might be willing to tell you again.

    2)Make an estimate of the basis.  Make an estimate of your cost, one you think the IRS will accept.  So if you had, say, $10 deducted each week and Walmart sold you the stock at the Friday close of the stock that week in the Wall Street Journal you could figure out reasonably close how much the stock cost.

    3)Declare the basis as $0 and pay tax on the entire proceeds.  The IRS will accept that.

    Tom Young
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