Presumably there were no beneficiaries designated on the 401(k) and 403(b), otherwise these distributions have nothing to do with the estate. The estate will generally file Form 1041 reporting any distributions paid to the estate, pass Distributable Net Income through to estate beneficiaries on Schedule K-1, take a deduction for the DNI and receive a refund of any tax withholding beyond the tax liability of the estate. The refunded tax withholding will then become part cash held by the estate. Having had taxes withheld might delay the closing of the estate while awaiting the tax refund.
