How do i add the cost basis for "Undetermined Term Transactions for Non-Covered Tax". I do know the cost basis but 1099-b does not have this info.

[reliantbay]

For one of the transaction that was bought in 2017 , 1099-B does not have a cost basis. it is being reported as UNDETERMINED TERM TRANSACTIONS FOR NONCOVERED TAX LOTS . also says (Report on Form 8949, Part I with Box B checked or Part II with Box E checked. Basis is NOT provided to the IRS. (Line 12)
“Date acquired,” “Cost or other basis,” "Accrued market discount," "Wash sale loss disallowed" and “Gain or loss (-)” are NOT reported to the IRS.)

I do know the cost basis and want to enter . i did check the box "The cost basis is incorrect or missing on my 1099?B" but should i enter the cost basis, on box 1e  or Where do I enter it?

[MinhT1]

Yes, if you know your cost basis, you should enter it in box 1e, and as you have held this stock for more than one year, you should check it as long term (Box E).

[BobKJ]

I have the same issue as the original forum posting...so the expert advice is, in TurboTax, to fill in the boxes of the 1099-B Form 8949 that the brokerage firm did not provide information for if the taxpayer has the information?  I want to do a double check since I guess I would have thought that TurboTax would have had a way to enter the taxpayer's information but leave the information inputs on the Form 8949 as the brokerage firm had prepared it.

[AmyC]

The IRS forms only allow one cost basis and proceeds box per action. The program must use what you decide is correct for your basis. The IRS expects you to keep track of your basis and last summer issued an example of a spreadsheet they now expect as well. See what the IRS expects here.

@BobKJ

[Jeff_AZ]

Follow up question on spreadsheet.  Does one have to mail in this spreadsheet with Form 8453 for noncovered box E lots or can one simply submit combined averages on Form 8949 which came from one's spreadsheet?

[PattiF]

You do not have to mail in the spreadsheet with Form 8453 and Form 8949. 

If you're required to mail in forms 8949 and 8453, do so within three days after the IRS has accepted your e-file. Here's the mailing address:

Internal Revenue Service
Attn: Shipping and Receiving, 0254
Receipt and Control Branch
Austin, TX 73344-0254

@Jeff_AZ