Traditional IRAs have always allowed non-spouse beneficiaries to rollover IRAs as a DESIGNATED BENEFICIARY ACCOUNT (DBA). Each of your three beneficiaries have until December 31 of the year following the date of death to 1) make an election to take all of the money and be taxed on the full amount of the IRA with no adjustment for basis (unless there are non deductible contributions a traditional IRA will have zero basis); 2) spread the distribution over 5 years and be taxed OR 3) to rollover the inherited IRA to a designated beneficiary account and be subject to required minimum distributions over the beneficiaries individual life time.
It is important that the new account be title as follows The "Deceased Person" IRA for the benefit of "Beneficiary". For example, if Ned Jones died and left his traditional IRA to me the title of the new account would read "Wells Fargo Bank IRA C/F Max K. McNeal as beneficiary of Ned Jones IRA" or alternatively the "Ned Jones IRA F/B/O Max K. McNeal". This is known as a beneficiary IRA or sometimes an inherited IRA. Failure to properly title the new account will result in immediate taxation to the beneficiary. To my knowledge the IRS has never allowed anyone to redo a botched account title.