Do I need to mail 1099-B along with Form 8949 & 8453, if there are cost basis not reported to IRS in box B of the 1099 consolidated and If there were adjusted washsales?

[MarilynG]

No, you don't need to mail your 1099-B; the IRS has a copy, even though this is mentioned in some entry areas.  If you entered a summary of sales, you may need to attach a statement to Form 8453 to mail in after you efile.

Your 'Filing Instructions' that print with the PDF copy of your return will tell you what to mail and where to send it, if needed.  The goal is to have as little paperwork as possible.  

If your Cost Basis is listed on the 1099-B, but 'not reported', just enter the amounts shown.  If it was blank and you had to enter your own cost basis, then you may have to mail in Form 8949.

The Adjustment Code for wash sales is W, which you can enter if it doesn't appear on your 1099-B.  If you adjusted amounts, you may have to mail in Form 8949.

Here's more detailed info:

https://ttlc.intuit.com/replies/6813250