topic 1099-B with incomplete information (cost-basis) in Get your taxes done using TurboTax

1099-B with incomplete information (cost-basis)

main0stage — Mon, 09 Mar 2026 08:56:52 GMT

Computershare sold 4 shares on my behalf that triggered 1099-B. The forms advices to figure out cost-basis based on my personal records. These stocks are also marked as 'noncovered'. I have acquired these stocks as employee stock purchasing plan, for past 10 years. I have acquired over 1000 such shares, so i do i figure which 4 were sold and when they were acquired? Or can i just pick the month when stock was high, to minimize the impact of tax?

Re: 1099-B with incomplete information (cost-basis)

JohnB5677 — Sun, 06 Mar 2022 21:30:57 GMT

The accepted method of determining which stocks are sold is FIFO (First In First Out). So the oldest 4 shares that you have are the shares that you sold.

Re: 1099-B with incomplete information (cost-basis)

Bayhill26 — Fri, 24 Feb 2023 20:51:23 GMT

I am trying to help my Father, who has dementia so i cannot ask him for any records of Shares purchased. He too received a 1099-B from Computershare in which only 0.245 Shares of his ASPP were old. it tells me the price they were sold at but the Cost or Other basis box ( Box 1D) was blank.

I understand the recommendation is FIFO but I don't have any clue to when they were purchased or at what price.

Are there any other ways to fill in this required information?

Re: 1099-B with incomplete information (cost-basis)

JohnW152 — Fri, 24 Feb 2023 21:26:25 GMT

If all your efforts to find the cost basis fail, in the end you many just need to make a good faith estimate of when the shares were purchased, and research online for a stock price on that date or within a particular date range.

When don't have original transaction confirmation, you need to make an educated guess as to the cost basis. Otherwise, the IRS will presume that the cost basis is zero.

If you can make an educated guess as to a date range in which the shares may have been purchased, you can use historical prices at the start and end of that range to compute an average stock price for that time period.

Be sure to keep a record of this calculation, stating your assumptions and the figures used. It's possible the IRS will want to know where the basis came from.

Please see the TurboTax Help articles How do I find a stock's cost basis? and How do I find a stock's cost basis if I don't know when it was purchased? for research possibilities.

@Bayhill26