Generally, the entire interest in a Roth IRA must be distributed by the end of the fifth calendar year after the year of the owner's death unless the interest is payable to a designated beneficiary over the life or life expectancy of the designated beneficiary.
If paid as an annuity, the entire interest must be payable over a period not greater than the designated beneficiary's life expectancy and distributions must begin before the end of the calendar year following the year of death. Distributions from another Roth IRA cannot be substituted for these distributions unless the other Roth IRA was inherited from the same decedent.
If the sole beneficiary is the spouse, he or she can either delay distributions until the decedent would have reached age 70½ or treat the Roth IRA as his or her own.