From IRS: "If a surviving spouse receives a distribution from his or her deceased spouse's IRA, it can be rolled over into an IRA of the surviving spouse within the 60-day time limit, as long as the distribution is not a required distribution, even if the surviving spouse is not the sole beneficiary of his or her deceased spouse's IRA". It makes no mention of it being a 2nd, 3rd, of 4th spouse, only spouse. I suppose there might be time limits in the actual code.