Should I amend my 2018 tax return if we received a 1099-R? The 2b box has the "total distribution" box checked. And the distribution code is marked G.

[Critter]

You should even though it will not change anything since none of it is taxable but doing so will avoid the IRS letter you will get in a couple of years telling you you missed reporting the form.  

[dmertz]

If the code G Form 1099-R has a nonzero amount in box 2a that indicates a rollover to a Roth account, you must amend.