Diane,
Actually, I think I figured this whole issue out--
Whether you use the summary method to input 1099B information, list each trade individually, or you import the transactions successfully from your broker, it's all about the SALES CATEGORY...that is, Box A thru F. Successfully importing 1099B transactions from a broker should populate the sales category correctly.
If your manually keyed in transactions or summary 1099B transactions indicates a SALES CATEGORY of B,C,E or F (all of those are either "non covered" or "not reported"), just before you hit the DONE button after keying in your data, the program indicates "to finish reporting these sales, follow the mailing instructions" with a link to some confusing (until you figure this all out) instructions. But if your sales category is either A (short term covered) or D (long term covered), you don't "see" the mailing instructions and don't have to complete a form 8453 (unless, of course, your imported data surprises you by indicating something besides sales category A or D).
Finally, you only need to print the 8453 to send to the IRS along with the particular 1099B that has the trade(s) with sales categories B,C,E or F. You do not need to print out form 8949 listing all your transactions. They're waiting to see just the statement of non covered or not reported transactions. Nothing more.
Once I figured this out (the culprit was Bitcoin trades on Robinhood...you can't import the crypto 1099B and the sales category happens to be B--short term non covered), I realized that all I need to do is send a copy of that particular 1099B and a copy of the form 8453. That's it.
Again, all my summarized transactions, manually input individual transactions, and imported transactions (from broker) had "short term covered" (sales category A) or "long term covered" (sales category D), which does not require supporting documentation to be sent to the IRS. JUST the Bitcoin trades were "not covered" or "not reported".
