Am I correct in assuming that estimated Federal taxes on required minimum distributions from certain retirements accounts are not due until after the RMD is taken?

it depends. There is a 50% penalty tax if you were required to take an RMD but didn't.  Please view this IRS source for further details.  Also there is a special COVID provision now that might be pertinent to you. You may read about that here.

Thank you for your response.  

My question simply relates to when must make estimated tax payments on an RMD that is taken on a timely basis.  Does one need to make estimated tax payments due on the anticipated amount of the withdrawal on a quarterly basis, or if one takes the withdrawal in the fourth quarter of the calendar year, does one need to make the estimated tax payment in that quarter and not in the other three?

If you will not have tax withheld directly from the distribution then the estimated payment is due for the quarter that the distribution was taken.  So if you don't take a distribution until December then the tax is due would be on  the 4th quarter estimated payment.  

It depends. My suggestion is to make 4 equal quarterly estimated tax payments to avoid being assessed a possible estimated tax penalty.  You may also request that the trustee of your account take out a suitable amount of tax to reduce the tax liability at the end of the year.

Thank you for your response.

It was very helpful.

Thank you.

My understanding is that estimated taxes are due when Income is received  So, taking the entire RMD in the 4th Q means it is fine to make a 4th Q estimated tax payment to cover tax liability. 

JTM