@MH - You don't have to send the IRS copies of 1099-B forms. They do already have that. But 1099-Bs do not always have complete information. If there were sales for which basis was not reported on the 1099-B, (box B, C, E, or F is checked on Form 8949), then you have to either enter each transaction individually on your tax return, or send the IRS a statement showing all the information that would be on Form 8949 for the individual transactions. What you send with Form 8453 is the statement listing the details of the individual sales.
