@phildonniain the situation discussed in this thread, if you use summary entries and have not individually entered each adjustment transaction and any with cost basis not reported to IRS, then you are required to provide a statement of those transactions. You do have the option of creating "the statement" yourself in whatever format you like so long as the necessary entries are provided. However, again, in the case of hundreds or thousands of transactions that may need to be individually entered you may in fact need to send the 1099-B as the supporting statement along with 8453. Again - Turbotax correctly instructs when 8453 must be mailed in and when you mail it you cannot send a note saying "Hey guys, you already have the 1099-B, go look at it" - you must attach the statement to it.
