Check to see if the coverages use the birthday rule. We had that issue where dual coverage the first birthday is first coverage. Inotherwords you don't get to pick. My company coverage was about the same as my husband's but his birthday was first so 2 plans always applied his first. Then my company plan said the other insurance already paid 90% so we pay nothing since our coverage is 90%. They didn't pay 90% of the 10% unpaid. It was a complete racket. We ended up dropping the secondary medical coverage and just using 1 family plan.