A marriage that lasts at least ten years leaves a permanent mark on the Social Security system — in your favor. If you were married for ten years or longer, are currently unmarried, and are at least 62, you can claim a benefit on your ex-spouse’s earnings record worth up to half of their full benefit; section “Social Security” covers the mechanics.
The detail that makes people misjudge this: it costs your ex-spouse nothing. Their benefit is not reduced, they are not notified, and a current spouse of theirs can claim on the same record at the same time. Remarry, and you generally forfeit the ex-spousal benefit; if that later marriage ends, it can revive. If your ex-spouse dies, the divorced-spouse survivor benefit can rise to 100% of their benefit. The ten-year line is the date the marriage is legally dissolved, not the date of separation — so if separation arrives at nine years and six months and the earnings records are badly unequal, the simplest negotiation lever in the room is to extend mediation, defer the entry of the final judgment, or let the matter sit on the court’s calendar until the marriage clears the threshold. The lower earner gains a government-backed annuity stream that can run for decades; the higher earner gives up nothing, because their own benefit is not reduced by the ex-spousal claim. It is the rare divorce variable that is positive-sum.