Get your taxes done using TurboTax

You do not need to send your 1099-B with your amended return.  Most likely, the IRS already has a copy of your 1099-B, as the broker will send a copy to the IRS whenever they send a copy to you.

 

If the IRS wants to see it, they will ask for it; it's not a big deal.  In any case, your amended return is complete and valid without it.