I need to mail form 8453. Box is checked for form 8949. Do I print and attach from 8949? It did not print or clarify in instructions for mailing form 8453.

If you reported your investment sales using the summary total method, then you will have to send supporting documents.  Its possible you may have chosen this method unintentionally as it is usually reserved for taxpayers with large volumes of transactions who don't want to list every transaction or are unable to import because of the volume.

Short Answer:  You do not really need to mail Form 8949, but you do need to mail your supporting statements, such as your brokerage statements (Form 1099B) and Form 8453.

When you use this summary method of reporting (i.e. you just entered your summary totals and not each individual transaction), in some cases, the IRS still wants you to send the same details that are shown on Form 8949 (i.e. sales date, cost, sales price, adjustments, etc) but they allow you to send supporting statements instead of actually filling out every single transaction on Form 8949.  Most people send their 1099-B forms received form their brokers as these usually contain all the information for the transactions.  

Note:  In limited situations, you’re allowed to summarize investment sales without providing complete details, but Turbotax will tell you when your sales meet this criteria and will not prompt you to mail any statements.

So, if you are being prompted to mail further statements, Form 8453 says to attach Form 8949, Sales and Other Dispositions of Capital Assets (or a statement with the same information), if you elect not to report your transactions electronically on Form 8949.

When you use the summary method, TurboTax only produces a Form 8949 with the summary totals that you entered, not the individual transactions, so the Form 8949 that is included in your return is NOT sufficient for this purpose (though, you can include it with the mailing as a reference).  Thus, to satisfy the requirements of utilizing summary reporting, you need to use Form 8453 to mail the details of your transactions (i.e your brokerage statements Form 1099Bs). 

there is no explanation whatsoever in your online form. i selected to summarize and now have to mail papers.

Yes agreed - you should have told us that if we summarized we would have to mail the form in.  Also you did not even tell us on the instructions that the actual 1099B needed to be mailed - now I have to re-mail.  Poor instructions!

Where do we mail our 1099-B that shows the breakdown of purchases, along with 8949 and 8453? I just need an address.

Yep, I probably would have entered each one if TurboTax had explained the difference. And yeah, there's nothing saying that the 1099-b needed to be mailed as well. Kinda curious why I spent the extra money for this...

I definitely would have entered the detail versus this print and mail. TT talked me into summarizing and then made me pay the painful price..

Did anyone having to mail this form cause the irs to take longer processing your return and end up delaying your refund? I fell into this trap this year so now I'm curious if this is going to hold things up.

I too got prompted - this is from Penny stocks in which I invested $30 and lost a $1 total! There were only 4 separate transactions so I would have listed them all out if I knew that selecting "summary" would cause this issue. Such a small amount of money to now have to mail in forms. I wish TT would warm you about this when filing out the 1099B info.

For 2018 does this same requirement exist as for 2017 to have to mail in the details of stock sales or has Turbo Tax added a feature where you could attach a PDF when you eFile

For those who complain about having to send the form to the IRS: this year (2018 tax return) Turbo Tax CLEARLY tells you (during the preparation of the data) that if you summarize you will then need to send the Form 8453 by mail. I decided to do it anyways, since I have 2 SMA's with 100-200 individual stocks each. However, while TT tells you to send the Form 8453 with the 1099-B during the preparation of the data, the printed filing instructions are not clear about the actual documents that need to be send with Form 8453. It actually says in the filing instructions: "Attach the following items to Form 8453: Form 8949 or an acceptable Continuation Sheet for Schedule D." Which, as we know from the Recommended Answer above, it's wrong. You need to send the 1099-B, not the Form 8949

IRS requires detail  to be listed on Form 8949,
or on your own forms (e.g. consolidated 1099-B) which have the same information and in the same manner as Form 8949.
so you could prepare a separate 8949 and mail that.
Some brokers have been known to supply the 8949 in PDF format ready for mailing

It's also possible to have multiple 8949s
Any 8949 showing code M has a mailing requirement, and only the details related to those particular totals have to be supplied. don't mail in the 8949 showing a code M, it will be attached to your e-Filing.

Interesting... I have another question: my Form 8949 includes only one transaction with the M code (a $3 "Box B" short term transaction that wasn't reported to the IRS). On the back of Form 8949 there are two reported long term transactions (without code M). However, I summarized a large number of reported transactions in my tax return (Box A or D - Short or Long Term transactions that have been reported to the IRS): they are listed in the Schedule D (lines 1a, 8a and 8b) but not in the Form 8949. With the Form 8453, do I need to send the 1099B only for the "Box B unreported transaction" that has a code M, or do I need to send also the 1099-B's that include all the other reported transactions?

I guess I found my answer on the IRS website (in the instructions for Schedule D): Lines 1a and 8a— Transactions Not Reported on Form 8949

You can report on line 1a (for short-term transactions) or line 8a (for long-term transactions) the aggregate totals from any transactions (except sales of collectibles) for which:

    You received a Form 1099-B (or substitute statement) that shows basis was reported to the IRS and doesn't show any adjustments in box 1f or 1g;

    The Ordinary box in box 2 isn’t checked; and

    You don't need to make any adjustments to the basis or type of gain or loss reported on Form 1099-B (or substitute statement), or to your gain or loss.

If you choose to report these transactions on lines 1a and 8a, don't report them on Form 8949. You don't need to attach a statement to explain the entries on lines 1a and 8a and, if you e-file your return, you don't need to file Form 8453.

as i said, only mail detail about the line with code M.
Did you summarize with only one transaction ?  that's what it sounds like. You can go back and just enter that one manually, eliminating code M.

You're right, the non-reported Box B transaction was only one line but I inserted it when I was inserting all the other ones (summarized as well, but of type A and D) and I might have picked the "Summarize" option by mistake. I already filed to the IRS so I'll have to send the Form 8453 unluckily. I just wanted to be sure that I don't need to send the hundreds of pages of the 1099-B for all the other transactions, thank you for confirming it.

OK . IRS has form 8949 available in fillable PDF format which you can use to itemize your transaction. Just fill in your name and SS number.

If the IRS receives copies of all 1099(B) forms, then why do we still have to mail these forms to them along with Form 8949. I chose to enter a summary of all transactions (i.e. cost basis and proceeds) instead of entering each sale (basically, copied what was on the consolidated 1099B form). Upon completion, I was still reminded to send Form 8453 along with Form 8949 and 1099B to the IRS. Again, isn't this redundant work if the IRS already receives all 1099 forms?

@MH you can summarize all the transactions and still not need to send a form 8453 afterwards, but this is only valid for transactions that are listed as already reported to the IRS in your 1099-B. If any of those transactions is of type “not reported”, you need to detail them in form 8949 otherwise you will have to send the 1099-B’s with form 8453.

@MH  some tax preparers here have posted in agreement with your argument.
However, that's not what the IRS instructions say, nor is it what the TurboTax instructions in the pop-up box say.
If you were right, hardly anyone would ever Import from a Turbotax Financial Partner. Probably 95 percent of reported sales are in category A or D and on a form that is also supplied to the IRS.

PS, for category A or D it is the adjusted sales that have to be itemized.
Turbotax default action  takes the easy way out and marks the whole pile "M" (mail it in), putting you in an inconvenient position..

The 1099-B worksheet tells me I need form 8453, but TurboTax does not generate this form for me.  I found the blank form but it was not autofilled with my taxpayer id info, I was not able to enter it, and further, I was not able to print it out blank. 

I ended up needing to go to the IRS site to print out a blank form, but I think TurboTax should generate and print out this form for me, noting that I need to attach my 1099B and to mail it in even though I am otherwise e-filing.

I understand what you said happened but below is what TurboTax does so therefore there must be some type of information not translating properly.  However, you solution works for you.

Yes, the 8453 is automatically generated by Turbo Tax and is sent after the return has been e-filed. In answer to your question about the 8949, if this is a form in your return, then it did get e-filed with the remainder of the return.

Yes, you do need to mail your supporting statements, such as your brokerage statements (Form 1099B) and Form 8453, but you don't need to include Form 8949 since TurboTax filed this form electronically with your tax return. You can include it for reference purposes, if you like.

@LadyGoGo

Is there a way to amend and do it electronically?  Do I need to fill out a 8949? 

This is first time that I have ever had this come up.