How do I stop a return? Went to print and the 1099-R income never made it.

If you've already filed your return, it's not possible to retrieve it, unfortunately.

If you filed your 2020 tax return with TurboTax, it can't be stopped and pulled back.  It's as if the return were dropped into a mailbox and already on the way to the Post Office.   

The IRS will begin processing returns on February 12 on a first-come-first-serve basis.  To make any changes, you'll have to wait until your return is either accepted or rejected before you can make any changes.

• If rejected, you can make any necessary changes regarding your 1099-R.
• If accepted, you'll need to amend your return. 

Here is a TurboTax FAQ that explains the process of amending.