"Please don't tell me my only option is mailing my 1099b."
@abra-shi
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.
No mailing is necessary.
