After you file

petergabp:
You are posting in an already-answered thread from last year that won't show up in the forum as needing help.   No one but the IRS will know what specific things they are looking at in your return.     The term "documents" used above can mean W-2 forms, 1099's, etc.   Those are things the IRS receives from payers.  A copy is sent to you, and another copy is sent by the payer to the IRS.  But the IRS can pull a return for review for any number of things, including at random.

If you have a question about your IRS letter, there may be an IRS phone number on it.  The TurboTax free Audit Support Center can also answer questions about IRS letters during business hours.   To get the phone number click the blue "Get Help" button at this link and follow the prompts.
<a rel="nofollow" target="_blank" href="https://support.turbotax.intuit.com/irs-notice/audit-support/">https://support.turbotax.intuit.com/i...>