I filed a 1040 tax return with form 8949 with e marked for long term realized gain /loss as well as schedule D parts 1 & 2 for long term gains losses and short term gains losses and schedule E -this was all e filed to IRS so I do not understand why my accountant has me mailing I a form 8453 with the box Form 8949 checked and he is attaching copies of my forms 1099B from fidelity investments on my short term and long term transactions - this seems redundant and unnessary to file this form 8453 with attachments when this was all already reported on my 1040 tax return on schedule D, Schedule E, and form 8949? Do I need to also mail in this ??