Social security benefits can be confusing, especially if you’re divorced and unsure of how much you’re really entitled
to. However, the rules for collecting after divorce are pretty straightforward. You qualify to collect on an ex-spouse’s social security if: your marriage lasted at least 10 years, your ex-spouse is unmarried, your ex-spouse is age 62 or older (however, FULL retirement age is 66 for those born before 1955 and 67 if born beginning in 1955), the benefit you would receive on your ex-spouses benefits would be less than what you would receive on your own, and finally the last requirement is that you would receive social security benefits separate from your ex.
Source: Mediation and Counseling Blog