I have had a client for 4 years and was notified today that there is missing RMDs from years back to 2012. She retired the first time (age 75) in 2012 but went back to work in 2016. The city that she works for switched from a 457 Plan to a 414(h) during that time and she never paid into the 457 again after the 2012 separation. 

Known: She missed her RMDs for 2012, 2013, 2014, & 2015.

Unsure: Would she still be required to take RMDs from the plan during the years that she was re-employed with the city? 2016-2019 

She retired the 2nd time in October 2019. 2020 was waived for COVID but she did miss 2021.

I plan on having her take the missed RMDs and file Form 5329 (for each year) to request a waiver of the 50% penalty.

Should I go all the way back to 2012 or just address the 6 years that would be auditable?

Thanks for any input.