Did not take RMDs

[MacJazzM]

Yikes! I just learned that we probably should have been taking RMDs for years from my husband's IRA and two of mine. He has an MBA and Master's in Physics and was very careful when preparing our taxes.  Now he has Alzheimer's and I must do the taxes.  Is it possible there was a legitimate reason for not taking the RMDs? 
What now?

I really want to get this cleared up even if it means paying oodles.  'Hate to be arrested for not paying taxes.

Thanks for any suggestions. 

[DoninGA]

It would be best for you to seek out a local tax professional to get assistance with this situation.

[Mike9241]

with multiple years involved it's best to use a pro. to give you an idea of what you'll probably have to do is to take all missed RMDs immediately.  file amended returns for every year the RMD was missed and include form 5329, requesting abatement of the penalties. you'll have to explain the reason they were missed and include a statement that the missed RMDs have been taken. then cross your fingers and hope the IRS does abate the penalties which can be 50% of the amount that was not timely distributed.