...

http://www.ssa.gov/retire2/divspouse.htm

If you are divorced, but your marriage lasted 10 years or longer, you can receive benefits on your ex-spouse's record (even if he or she has remarried) if:

* You are unmarried;
* You are age 62 or older;
* Your ex-spouse is entitled to Social Security retirement or disability benefits and
* The benefit you are entitled to receive based on your own work is less than the benefit you would receive based on your ex-spouse's work.

LZ可能（最好）再婚，也可能在美國交的SSN稅多於他，所以SSN這個東西不要太指望。