Coronavirus related distribution partial repayment

[jlew1229]

 A client took a 100K Coronavirus related contribution and is claiming 33K as income each year, (2020,2021 and 2022)  and wants to make a partial repayment.   I am not sure what this partial payment amount will be quite yet, but for example purposes, I am going to say 50K.   Do I have to go back to 2020 and file an amended return for 33K and than an amended return for 2021 of the remaining 17 K repayment balance?   Or since he has not filed the 2022 return yet, apply 33K of the repayment to 2022 and only have to amend 2021 for the repayment balance of 17K.?   

I can't find in the instructions how to apply partial repayments. The examples I can find is if the repayment is in full.  

Thanks for your help.  

[qbteachmt]

It's covered here:

https://www.irs.gov/pub/irs-pdf/p590b.pdf

"If you choose, you can generally repay any portion of a qualified disaster distribution that is eligible for tax-free rollover treatment to an eligible retirement plan."

"If, during a year in the 3-year period, you repay more than is otherwise includible in income for that year, the excess may be carried forward or back to reduce the amount included in income for the year."

And they even provide an example.