I do my taxes with TT every year. I did my 2016 return using TT Home & Business. I just got a form CP2000 from the IRS saying there's a discrepancy and I owe them several thousand dollars.
I reviewed what they're talking about and it's regarding a form 1099-B from Vanguard. I believe this was imported electronically. I have the form open in TT but not sure how to tell if it was pulled in that way or I entered it manually. I tend to do the import electronically. Anyway, there are two entries on the paper form which we just downloaded and printed from Vanguard. Both entries are for the exchange of funds in a retirement account.
I can see the 1099-B and first transaction in TurboTax, but don't see the second transaction in that 1099-B anywhere in TT. Is it possible TT didn't pull the second transaction in? Was there a bug like this or something at the time?
To make it more confusing, the IRS form seems to indicate they see it somewhere in my return, except the cost basis was used as the proceeds amount and somehow "reported to them by third parties" they have the cost basis as the proceeds. I don't find either number in my form (printing all forms to PDF and searching, don't see a way to search by an amount in TT).
It sounds like there was simply a transaction in your retirement account, which did not need to be reported at all. Just send the IRS the printed document showing the purchase and sale both within the same retirement account. The cost basis, which came from selling the first fund, should be the same as the proceeds, since you took the money from the sale and used it to buy the new fund.
Again, there was no error on the part of TurboTax. Purchases of stock are not reported on your tax. The sale of stocks in your retirement fund should not be reported on your 1099-b. If the transaction involved selling and buying within the same retirement account, there was nothing to report. You could try and get a corrected 1099-b, or you could simply show the IRS balancing purchase and sales in a retirement account.