While the IRA owner is alive, only the IRA owner can change the designated beneficiary of the IRA. Exceptions may apply if there is an attorney-in-fact, in which a power of attorney includes provisions that appoint that agent to act on the IRA owner's behalf. Similar exceptions apply to conservators, who can be appointed by a court to take care of legal matters for an IRA owner who is unable to do so.
After the IRA owner's death, the designated beneficiary, including a trust beneficiary, has the option of disclaiming the inherited assets. If the disclaimer is qualified, the assets will generally pass to the other primary beneficiary. If there is no other primary beneficiary, the contingent beneficiary will be treated as the designated beneficiary. If there is no other primary or contingent beneficiaries, the beneficiary will be determined according to the default provisions of the IRA plan document.
Beneficiaries should consult with their tax professional before disclaiming inherited assets.
For more information about inherited assets, see Disclaiming Inherited Plan Assets, Inherited Retirement Plan Assets - Part 1, Inherited Retirement Plan Assets - Part 2 and Refusing An Inheritance.
This question was answered by Denise Appleby