Mandatory TSP IRA withdrawals-my wife and I both turn 70 1/2 in mid-year 2020. Can we do our mandatory withdrawals any time in tax year 2020 such as January 2020?

[SteamTrain]

Yes...you can.

The calc and withdraw of the RMD for any TSP must be done completely separate, from the calculation/withdraw for IRAs .

One thing I was not aware of , until I did it, is that in the year you turn 70.5, the divisor used for the RMD depends on your age at the end of the same year you turn 70.5.  Example: IF you turn 70.5 in 2020, and also turn 71 by the end of 2020, then the RMD divisor is different than if you didn't turn 71 until 2021.  But I talked about it with the phone-Rep for my 401k, and when my calc didn't match theirs, I found out why then , and  they did the proper calculation for me

Certainly, for that first year you can delay the first one until the first few months of 2021...but then you end up taking two RMDs in 2021 and that ends up with a pretty large tax bump for 2021 taxes