All property owned by the deceased at the time of death should be generally included into the estate. It is possible that only part of estate goes through probation - not the total estate.
Actually for inherited IRA you have two options:
You can begin making the minimum required distributions (MRD) by Dec 31 of the year following the IRA owner's death. Your MRD are based on your life expectancy or the 5-year rule depending on whether or not you are a designated beneficiary.
If an IRA owner dies before age 70 ½ or has not started withdrawing the minimum distributions, beneficiaries of the IRA must follow either rule:
As you can see, these rules are not simple and you should plan the distribution carefully to minimize tax impact. From tax purposes it might be better to spread distribution over several years - otherwise you will be pushed into higher tax bracket and your tax liability might be huge.
If you are looking to compare the value of the inherited funds in IRAs with other tax-free inherited property - you need to consider potential tax liability.
Thus, assuming 25% federal and 5% state income tax rates on IRA distribution - $1000 in IRA account - if distributed - will be equal to $700 after-tax money.
That depends how do you structure the distribution: