How can I get a copy of my 2018 tax return?

To access your prior year online tax returns sign onto the TurboTax website with the User ID you used to create the account - https://myturbotax.intuit.com/

Start the 2024 online tax return by entering some personal information then click on Tax Home on the left side of the screen.

On the Tax Home webpage -

Scroll down to the section Your tax returns & documents.  Click on the Year and Click on Download/print return (PDF)

If you used the desktop CD/Download editions installed on your computer, the only copy of your tax data file and any PDF's will be on the computer where the return was created.  TurboTax does not store online any returns completed using the desktop editions.

Or go to this IRS website for free federal tax return transcripts - https://www.irs.gov/individuals/get-transcript

For a fee of $30 you can get a complete federal tax return from the IRS by completing Form 4506 - http://www.irs.gov/pub/irs-pdf/f4506.pdf

For copies of Colorado return, you will need to apply to the Colorado Department of Revenue. If they don't have them, I guess that answers your question about 2018.

Please see this page where you can apply for old returns online or by mail. I was surprised to see that they say they keep returns for 9 years and 6 months (this is on the DR 5714), so maybe they have your 2018 return laying around.