Durable Power of Attorney (DPOA)- Health Care: A legal advance directive that names a person (Patient Advocate) to act on the signer’s behalf in enacti...
In the event of your incapacity, without such a DPOA, you would not be able to continue carrying out actions that you intended, such as a Roth conversion.
Having a DPOA in place would have allowed the power-holder to complete the process of converting the funds to Roth, and paying the tax from the investment account, even though the gentleman in question was incapacitated.