Detail Reporting Exception: if you summarize Category A or Category D, Form 8949 is not needed for transactions without adjustments. No mailing is necessary.
If you have wash sales, it gets more complicated since those adjusted transactions have to be itemized on Form 8949 and the summary totals adjusted accordingly.
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.
You may supply details on your separate Form 8949, or other document with the same information and in the same manner as Form 8949.
Note: turboTax may suppress some covered transactions without adjustments that you entered in detail. 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.)
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The relevant box on Form 8453 is the last one, for 8949
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