After you file

If you did not save the tax files on a removable storage medium like a thumb drive  then the files are lost.  If you need a copy : 

 

You can get a return transcript from the IRS for free :  http://www.irs.gov/Individuals/Get-Transcript

 

For a $50 fee you can get a copy of the return from the IRS:  https://ttlc.intuit.com/questions/1901218-can-i-get-a-copy-of-my-tax-return-from-the-irs