RMD was not distributed in previous years.

[benjamin-olejnik]

I received a letter from a custodian of an inherited IRA that they had an administrative error and neglected to disturb $519.51 for the tax years 2017-2021 ($519.51 is the total for all years). 
I received the letter in November 2022 and immediately contacted them and requested they distribute that amount. The letter from the custodian says 2017-2021 to be distributed $2,373.70, Actual $1,854.19, Differential $519.51 (which I took in 2022 and is included in the total of the 1099-R).

I tried using TurboTax online to create form 5329 and listed an explanation. 5329 is showing up in my tax return (not submitted) but I think it is wrong. It is giving me an error stating “Form 5329-T: Waiver of tax should not exceed the minimum required distribution shortfall.” The original owner would have been 72, Turbo Tax is not recognizing this as an early distribution, and I cannot seem to edit the form.

Turbo Tax populated the 5329 to have Line 52 $2,374, Line 53 $1,854, Line 54 $0. Which is wrong I believe.

How do I edit the explanation that is in my tax return?

Should I delete their form 5329 and file by mail including my own 5329 or can I edit the 5329 form, it currently is locked for editing (font in blue)?

[MarilynG1]

If the failure to distribute your RMD for tax years 2017-2021 is an administrative error, and you received the back RMD in 2022, when you enter your 1099-R indicate that the 'entire distribution is RMD' in TurboTax (unless you rolled over part of your distribution). 

If you indicated in prior year returns that your distribution included RMD, (since you didn't know that it didn't) you won't be assessed a penalty and can delete Form 5329 from your return.  You are paying tax on your prior year RMD this year. 

Save documentation about the administrative error.

Here's more info on Reporting RMD's.