Do I have to file an amended return for a forgotten 1099-R (qualified rollover) that was not taxable and since it won't effect the outcome?

[rjcesar]

I found the 1099-R after I had already filed my return.

[KittyM · Accepted solution]

Yes, you will need to amend your return to report your 1099-R.  This is because the IRS also receives a copy of your 1099-R and they will send you a CP2000 in the next year or two treating it as fully taxable unless you have reported it as not being taxable.  

Amending your return is preferable to dealing with a CP2000.  Here's how to Amend My Return in TurboTax.