The cost basis of a stock or bond that you inherit is usually the FMV of that stock or bond on the close of trading on the date of death. Check with the executor of the estate to confirm but your are pretty sure the IRA will accept a basis if you can find out what the value of the bonds were on the date of death. Knowing that date, there are websites that can tell you the high, low and close of stocks and bonds for various dates. You need to do a little web hunting, but it's worth it because the option is to use a zero basis which the IRS would love but I doubt if you would. Hope this helps.
