After reading around it seems some people file one form 5329 and then attach a separate letter explaining what happened, while others submit form 5329 for each of the years they miss. In the IRS instructions it says "If you are filing Form 5329 for a prior year, you must use the prior year's version of the form."
In my case I missed RMDs for 2012-2017 because the Inherited IRA stayed with the original custodian but they never sent me an RMD notice, and I didn't know about the RMD rules. I discovered the missed RMDs in 2018 when I rolled it over to a new custodian. I calculated and took the RMDs from 2012-2017, then took the 2018 RMD separately in December of 2018.
The question is - since I took the 2018 RMD (in a separate transaction), do I even need to file a 5329 this year? The wording on the form says "Minimum required distribution for 2018" and "Amount actually distributed for 2018" which will be the same number... so the math for lines 54 and 55 won't even work.
You must file 2012, 2013, 2014, 2015 2016 and 2017 Forms 5329 requesting waiver of the 50% excess accumulation penalties for those years. You can send these together in a single envelope, but they must be sent separately from your 2018 tax return.
Your 2018 tax return will not include Form 5329 unless there is some other reason it is needed. You aren't requesting a waiver for 2018 because you took the 2018 RMD timely.
You must file 2012, 2013, 2014, 2015 2016 and 2017 Forms 5329 requesting waiver of the 50% excess accumulation penalties for those years. You can send these together in a single envelope, but they must be sent separately from your 2018 tax return.
Your 2018 tax return will not include Form 5329 unless there is some other reason it is needed. You aren't requesting a waiver for 2018 because you took the 2018 RMD timely.
So I wonder if it will hurt my case to e-file the 2018 return?