At tax time, you have the option to summarize your activity by Sales Category.
As an active investor, be aware that your category Box A or Box D sales without adjustments do not require Form 8949, so there is no reason to import or key in those transactions.
Instead use the "enter a summary" option to put your numbers on Schedule D Line 1a or Line 8a.
Category A and D are the covered transactions.
IRS calls it aggregating transactions.
TurboTax calls it "entering a summary"
Form 8949 forces you to group your activity according to the Box A-F Sales Category.
This is not really complicated.
Many of the answers on the forum have misinformation.
At tax time, you have the option to summarize your activity by Sales Category.
IRS requires details of all sell transactions to be listed on a Form 8949,
or on your other forms (e.g. consolidated 1099-B) which have the same information and in the same manner as Form 8949.
Either way, if you choose to summarize, you have to mail the transaction details to the IRS within three business days of IRS accepting your e-Filed tax return.(unless you have attached a PDF of the transactions details to your e-Filed return. TurboTax seems to be adding this feature now).
Exception: if you summarize Category A or Category D, Form 8949 is not needed for transactions without adjustments. No mailing is necessary.
If you summarize (recommended),
you only need to supply details of 1099-B covered transactions with adjustments that are not listed on your e-Filed Form 8949. and all non-covered transactions not listed there.
In other words, for active investors, generally this is a list of the Wash Sales.
Note: turboTax may suppress some covered transactions without adjustments. For those, no mailing is required !
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If you have two pages (for example) of Wash Sales,
use Adobe Reader to print those two pages. That's all you have to mail to the IRS, given that those wash sales are not on your e-Filed form 8949 already.
(you might enter them manually if they are few in number.)
If you were wise enough to avoid wash sales, you won't have to list or mail anything.
