I unexpectedly received a 1099B form after submitting my 2017 taxes. My stock transaction costs are higher than my proceeds (no gains). Do I need to amend my taxes?

[CherylW]

Yes, you do.  The IRS also gets a copy of your 1099-B, so if they don't see those transactions, they'll question it.

To amend:

Please wait until you receive your original refund amount.  Then, follow the instructions below.  The 2017 1040X isn't even ready yet, but you have until April 17, 2018 to amend without penalty.

You should wait until the return you already filed has been accepted and processed.

Form 1040X can’t be e-filed, so you will have to mail a copy to the IRS. See page 12 of the IRS instructions for 1040X (https://www.irs.gov/pub/irs-pdf/i1040x.pdf) for the address that the return must be sent to.

Include any W-2s or 1099s that have had federal tax withheld, ONLY if you made any changes to those sections.

To amend states, see this list for specific instructions:

All State Revenue Sites

To amend your return using TurboTax:

https://ttlc.intuit.com/replies/3288565