You have to reach out to the providing company (American Funds, Fidelity, Transamerica) and they MAY have a form that can be filled out for another person to have authorization to receive information.
An IRA or 401(k) belongs solely to an individual. Beneficiaries cannot gain access or receive information until a death certificate or probate documents have been supplied.
As stated previously by Christopher, you may need a special form, a power-of-attorney, or both to gain access. Often-times custodians will not honor a power-of-attorney until it has been recorded in the county records or issued by a judge.
Regards John Essigman www.bluecreek.net