TurboTax Online saves those past year e-filed returns if you filed using online version. But if you e-filed in CD/Download version, you would have to save the copy to your computer for future reference. TurboTax does not save/store copies online when you used the CD/Download version of the software.
If you no longer have that computer or saved copies, the other option you have is to reach out to the IRS to get exact copies. You can request an
exact copy of the returns for a fee instead of requesting a transcript. You can go here
Can I get a copy of my tax return from the IRS? for steps to take to get an exact copy from the IRS.
How do I get a copy of a tax return prepared with the TurboTax CD/Download software?