You make absolutely sure that each retirement plan, IRA, Roth IRA, 401(k) or other tax preferred retirement account has been reviewed as to the successor beneficiaries at your death. Each account or plan will have a unique form to be completed to appoint successor beneficiary(ies) at your death. Be certain that each plan has a signed beneficiary designation form and retain a copy of the form in your master file. The designation should have first, second and third beneficiaries if necessary or desired. For example, at my death, the beneficiary is my spouse, or if he/she died before me, my son or his children equally, or finally, your favorite charity. One thing that you never want to happen is for a retirement account to be paid to your estate or the estate of a beneficiary. When the beneficiary of the retirement account is an estate, the entire value of the plan is taxed immediately at the highest rate of income tax and if there is no will, the net proceeds are paid to your heirs at law, not necessarily the persons who you wish to benefit.
No document prepared for your estate plan (trust or will) will control the disposition of a retirement account. If the proper form is not completed and signed by you, the full amount of the plan will be paid out at your death and taxed at the highest income tax rate.