Somebody at a barbecue tells you your ex-wife can claim Social Security on your record.
Your stomach drops. You picture your check getting smaller. You picture your current wife's check getting smaller. You start wondering whether there is a form to file, a lawyer to call, something to stop it.
There is not. And you do not need one.
Here is the whole thing in two sentences.
Yes, a qualifying ex-spouse can claim benefits based on your earnings record. No, it does not reduce your benefit, your spouse's benefit, or anything else by a single dollar.
Their claim is paid out of the Social Security trust fund, not out of your check. It is not a slice of a fixed pie with your name on it. It is a separate benefit calculated from your record, and the existence of that benefit has no effect on yours.
So the barbecue was right about the fact and wrong about the consequence.
Let's go through exactly who can do this, what they receive, what you are entitled to know about it, and the one genuinely legitimate concern that does exist.