His & Her Benefits: Getting Ex's Social Security

Is it true that as a 64-year-old divorcee, who was married for 13 years and hasn't remarried, I would be eligible to collect half of my ex-husband's Social Security benefit? My ex-husband is 67 and has been collecting full Social Security for more than a year. I have been waiting to collect my full retirement benefit from Social Security until age 66, rather than taking reduced benefits early.

If I could collect half of his benefit now, could I switch to my own full benefit at 66? Then, could I switch again, to collect my ex-husband's full benefit, if he dies before I do? Also, could I collect his benefits retroactively?

S.A. Reagan

You don't have a choice between collecting your own benefit or your ex-spouse's until you reach your full retirement age.

If you are between age 62, which is the youngest age at which you can collect reduced retirement benefits through Social Security, and your full retirement age, which varies based on the year you were born, your application for benefits generally will be based on your earnings record, says Dorothy Clark, a spokeswoman for the Social Security Administration in Baltimore. If the portion of your ex-spouse's benefit to which you are entitled at the age you apply is greater than your own, you could receive a benefit equal to that amount.

But if you wait until your full retirement age to file for Social Security, you can restrict the scope of your application to your ex-spouse's benefit only, and continue to accrue credits for delaying your own retirement benefit up to age 70, Ms. Clark says.

Generally, here are the requirements for collecting based on an ex-spouse's earnings record: Your marriage had to have lasted at least 10 years; you can't be remarried; you have to be at least 62; and your ex-husband has to be entitled to Social Security retirement or disability benefits. Finally, unless you have postponed your own retirement benefit as described above, the benefit you are entitled to receive based on your own work has to be less than the benefits you would receive based on your ex-spouse's work.

If your ex-spouse has died, you can receive survivor benefits at age 60 (or age 50 if you are disabled), if your marriage lasted at least 10 years, and you aren't entitled to a higher benefit based on your work record. (You may be eligible if you still have a child at home as well.)

If you are at full retirement age or older when your ex-spouse dies, you generally would be entitled to up to 100% of his or her basic benefit amount. But you would continue to get your own amount, plus the difference between yours and his—and only if it is greater than what you are entitled to based on your own earnings record.

So, if the reader above waits until her full retirement age to file for Social Security and elects to receive half of her ex-husband's benefit at that point, she could switch to her own maximum benefit at age 70. And then, if her ex-spouse dies first, she could switch to his benefit again, as long as his benefit was greater than hers at that point.

However, if she starts collecting Social Security before her full retirement age, she is stuck with her own reduced amount, plus any portion of his to which she is entitled (whichever is greater), throughout her retirement. If her ex-spouse dies and she hasn't yet reached her full retirement age, she also could get a portion of his benefit amount (the percentage would be based on her age), if the amount were greater than what she was receiving at that point.

Write to Kelly Greene at kelly.greene@wsj.com