one of the girls i work with has health insurance through her husband, who works for the union, and had a couple of problems recently. she got a bill from her daughters ped. charging her for routine immunizations saying insurance wouldn't pay for it and had to fill out this strange form explaining why she had to go to the emergency room a few weeks back, as if they still hadn't "decided" if they would cover it. we live in nj. so, i dunno.
I have health insurance through my husband but our insurance tells you ahead of time if they will cover something. some times you can request a list of what they do and do not cover. but i live in oregon, so it could be really different. good luke to you.