Except in the case of it being able to be passed over to the successor, holder, beneficiary—and they would continue as if it were their own—the financial institutions, the intermediaries, would have to start tracking it immediately as if it had been converted into a taxable account. That would make it quite difficult, because often it's not until months afterward that you actually find out the holder has passed away, and your systems are not set up to sort of retroactively start tracking value.
